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0 Final Report :: C - Fire Codes IITK-GSDMA Project on Building Codes
Handbook on Building Fire Codes
Fire Adviser, Govt. of India {Retd.} Cochin Ex-Chairman CED-22 Fire Fighting Sectional Committee Bureau of Indian Standards.
Asst.General Manager{Retd},TAC/GIC,Ahmedabad Ex-Chairman CED-36 Fire Safety Sectional Committee Bureau of Indian Standards.
• This document has been developed under the project on Building Codes sponsored by Gujarat State Disaster Management Authority, Gandhinagar at Indian Institute of Technology Kanpur. • The views and opinions expressed are those of the authors and not necessarily of the GSDMA, the World Bank, IIT Kanpur, or the Bureau of Indian Standards. • Comments and feedbacks may please be forwarded to: Prof. Sudhir K Jain, Dept. of Civil Engineering, IIT Kanpur, Kanpur 208016, email: firstname.lastname@example.com
Handbook on Building Fire Codes
Page Ref Section-1 Section-2 Introduction Terminology 5-6 7-18 19-39 19-29 30-39
Section-3 Fire Science-Basic Principles Chapter 1 Basic Principles of Combustion Chapter 2 Combustion Process(Relevant to Fire Science) Section-4 Fire Extinction/Suppression Technology
40-174 40-42 43-47 48-65 66-164 165-174 175-185 186-201
Chapter 1 Constituents of Fire Chapter 2 Methods of Fire Extinguishment Chapter 3 Extinguishing Media Chapter 4 Fixed Fire Extinguishing Systems Chapter 5 First-aid Fire Fighting Equipment Section-5 Section-6 Building Fire Hazards Life Hazards in Buildings and Means of Escape / Egress / Exit Fire Safety in Building Design and Construction-Basic Principles
Section-8 Fire Protection/Fire Safety Management for various classes of Occupancies Section-9 Building Codes and RegulationsAn Overview
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Page Ref Annex-A Proposed Contents of Revised National Building Codes Legislation Relating to Fire Safety/ Fire Protection in India List of Indian Standards Relating to Fire Safety/Fire Protection Calorific Values of Common Materials and Typical Values of Fire Load Density Broad Classification of Industrial and Non-Industrial Occupancies as per degree of Hazard Qualifications and Experience Proposed for Fire Protection Engineer/Consultant for Registration/Accreditation Role of Insurance Industry vis-a-vis Risk Management Measures-An Update List of Figures Graphic Symbols for fire Protection Plan Fire Protection - Safety Signs 247
249 -257
258 -260
261 -264
265 -267
268 -271
Annex-H Annex-I
272 -274 275 -279
280 -287
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Handbook on Building Fire Codes
Building, whether used for living, working, entertainment or for other purposes, forms an integral and major constituent of human habitat. As a sequel to the all round socio-economic progress, and the steady urbanisation processes gathering momentum all over our country for the past few decades, there has been enormous increase in the number of buildings of all classifications, including high-rise and special buildings, especially in the urban and surrounding areas. With the technological advances on all fronts, not only the factor of susceptibility, but the complexity of fires, explosions and the hazards which these buildings are exposed to have also increased manyfold. These hazards have been instrumental in causing heavy losses in lives and property throwing up fresh challenges to planners, architects and fire protection services in evolving better and improved methods of design and fire protection in order to mitigate such losses. The first version of the National Building Code was published by the Bureau of Indian Standards in 1970, which was subsequently revised in 1983. The 1983 edition of NBC consists of 10 Parts, of which Part-4 deals with Fire Safety / Fire Protection aspects. All the Parts of NBC, including Part-4, are under revision now.The recently revised version of Part 4, Fire and Life Safety, is under print and expected to be out by June 2005, as per information furnished by BIS. Part-4 of the NBC, dealing exclusively and comprehensively on Fire and Life Safety is the prime Code document on the subject in our country, supplemented by several other State and Local Authority level Development Control Regulations and Building Bye-laws. The whole objective of these regulatory documents is for ensuring the implementation and maintenance of basic minimum standards of construction, structural as well as fire and life safety in buildings of all types of occupancies which is, infact, the social, moral and legal responsibility of the entire community. Building Codes and Fire Protection are two sides of the same coin which serve to alleviate losses of lives and property due to fire. Buildings vary so much in their interior layout, siting, height, area,
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It is also recognised that absolute safety from fire is seldom attained in practice. use and construction. For ensuring proper and adequate implementation of the provisions of the Building Codes and Regulations. To provide necessary guidance and assistance in this regard the proposed qualifications and experience for their registration / accreditation. are also included in one of the Annexures to this Handbook. as well as the long standing experience of the authors in the field.Handbook on Building Fire Codes cubic capacity. Fire Protection / Safety and such other related subjects for all those concerned with the formulation.0 Page 6 . Further. both active and passive. also provide reasonable safety from the effects of fire. Since such topics are seldom taught in any educational or academic institutions. being the first of its kind. the fire protection measures incorporated for the building. The architectural and structural design of a building and construction have a significant effect on its fire safety standards. to be published on the subject. it will be necessary to associate qualified and trained Fire Protection Engineers / Consultants with the building industry right from the planning and design stage of the buildings. an attempt has been made through this Handbook to provide necessary information and guidance for facilitating better understanding and knowledge of various aspects of Fire Science. more exits. including our National Codes. operation and implementation of the relevant Codes and Standards on Fire and Life Safety. This Handbook has been prepared based on latest study material available with internationally accepted technical literature on fire and life safety. and nothing in these documents prohibit better type of building construction. it has to be borne in mind that while implementing the provisions of the Codes and Regulations. IITK-GSDMA-Fire 05-V3. Building Codes and Regulations prescribe only the basic minimum requirements for achieving fire and life safety in buildings. must also be taken into consideration. and Building Codes. All those concerned in the construction activity have to keep an up-to-date track of all the current Building Codes and Regulations as well as the relevant standards on the subject. It is hoped that this Handbook. will be found useful for reference by all concerned. or provision of other safer conditions than what are prescribed in the documents. Similarly. the nature of occupants as well as the activities pursued by them in the building.
4. or by fire resisting construction.TERMINOLOGY 1. should the other be affected by fire. Alternative exit One of two or more exits. Note:. Auto Ignition Temperature (AIT) AIT is the lowest temperature at which substance will ignite spontaneously or by itself without any external source of ignition. building services ducts and stairways are not classified as atria. balcony or flat roof which enables a person to reach a place of safety. 5. IITK-GSDMA-Fire 05-V3. Atrium A space within a building.Enclosed lift wells. to ensure that one is still available. initiating an alarm of fire and initiating other actions as appropriate. 3. Automatic Fire Detection and Alarm System Fire Alarm system comprising components for automatically detecting a fire. 6. passing through one or more structural floors Note:. each of which is separate from the other.A second stair. 2.This system may also include manual fire alarm call points. control and extinguish a fire by discharge of water. Automatic Sprinkler System: A system of water pipes fitted with sprinkler heads at suitable intervals and heights and designed to actuate automatically. Alternative escape routes Escape routes sufficiently separated by either direction and space.Handbook on Building Fire Codes HANDBOOK ON BUILDING FIRE CODES SECTION 2 .0 Page 7 . not necessarily vertically aligned. enclosed escalator wells. Note:.
Handbook on Building Fire Codes
Building Any structure for whatsoever purpose and of whatsoever materials constructed and every part thereof whether used as human habitation or not and includes foundations, plinth, walls, floors, roofs, chimneys, plumbing and building services, fixed platform, varandah, balcony, cornice or projection, part of a building or anything affixed thereto or any wall enclosing or intended to enclose any land or space and signs and outdoor display structures. Tents, Shamianahs, tarpaulin shelters, etc, erected for temporary and ceremonial occasions with the permission of the Authority shall not be considered as building Building, Height of: The vertical distance measured in the case of flat roofs, from the average level of the ground around and contiguous to the building to the terrace of the last livable floor of the building adjacent to the external wall; and in the case of pitched roof up to the point where the external surface of the outer wall intersects the finished surface of the sloping roof, and in the case of gables facing the road, the mid point between the eaves level and the ridge. Architectural features serving no other function except that of decoration, shall be excluded for the purpose of measuring heights. Co-efficient of linear expansion The amount by which unit length of a solid substance expands when its temperature is raised by 1oC is called the co-efficient of linear expansion of the substance.
10. Combustion Combustion is an exothermic, self-sustaining reaction involving a condensed-phase fuel, a gas-phase fuel, or both. The process is usually associated with the oxidation of the fuel by atmospheric oxygen with the emission of light. 11. Combustible material The material which either burns itself or adds heat to a fire. when tested for non-combustibility in accordance with accepted standard [c(1)]
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Handbook on Building Fire Codes
12. Compartmentation The division of a building into fire-tight compartments by fire resistant elements of building construction in order to control a fire for a stated period of time within the compartment of origin. 13. Compartment (Fire) A building or part of a building, comprising one or more rooms, spaces or storeys, constructed to prevent the spread of fire to or from another part of the same building, or an adjoining building 14. Compressed Gases Are gases which exist solely in the gaseous state under NTP (Normal Temperature and Pressure) inside the container. 15. Covered Area Ground area covered by building immediately above the plinth level. The area covered by the following in the open places is excluded from covered area (like garden, well & well structures, porch, portico, watchman's booth, security room, pumphouse, sub-stations or such other utility structures). 16. Cryogenic Gases Are liquefied gases which exist in the container at temperatures far below normal atmospheric temperature, but usually slightly above their Boiling Point at NTP, and at correspondingly low to moderate pressures. 17. Dead End Area from which escape is possible in one direction only 18. Down Comer An arrangement of fire fighting within the building by means of down comer pipe connected to terrace tank through terrace pump, gate valve and non return valve, and having mains not less than 100mm internal diameter with landing valves on each floor landing. It is also fitted with inlet connections at ground level for charging with water by pumping from fire services appliances and air release valve at roof level to release trapped air inside. 19. Element of Structure a) a member forming part of the structural frame of a building or any other beam or column; b) a loadbearing wall or loadbearing part of a wall; c) a floor;
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Handbook on Building Fire Codes
d) a gallery; e) an external wall; and f) a compartment wall (including a wall common to two or more buildings). 20. Emergency Lighting Lighting provided for use when the supply to the normal lighting fails. 21. Emergency Lighting System: A complete but discrete emergency lighting installation from standby power source to the emergency lighting lamp(s), for example, self contained emergency luminaire or a circuit from central battery generator connected through wiring to several escape luminaries. 22. Escape Lighting: That part of emergency lighting which is provided to ensure that the escape route is illuminated at all material times (for example, at all times when persons are on the premises), or at times the main lighting is not available, either for the whole building or the escape routes. 23. Escape Route Route forming that part of the means of escape from any point in a building to a final exit. 24. Evacuation Lift A lift that may be used for the evacuation of disabled people in a fire. 25. Exposure Hazard The risk of fire spreading from a building, structure or other property to an adjoining building or structure, or to another part of the same building or structure by radiated heat across the intervening space. 26 Fire Damper A closure which consists of a normally held open damper installed in an air distribution system or in a wall or floor assembly and designed to close automatically in the event of a fire in order to maintain the integrity of fire separation.
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Handbook on Building Fire Codes
27. Fire Detector A device which gives a signal in response to a change in the ambient conditions in the vicinity or within the range of the detector, due to a fire. 28. Fire Door A fire-resistive door approved for openings in fire separation walls. 29. Fire Exit A way out leading to an escape route. This can either be a doorway or even a horizontal exit. 30. Fire fighting Access Approach facilities provided to or within a building to enable fire service personnel and equipment to gain access thereto for fire and rescue operations. 31. Fire fighting Shaft A protected enclosure containing a fire fighting stair, fire fighting lobbies and, if provided, a fire fighting lift, together with its machine room. 32. Fire Lift The lift installed to enable fire services personnel to reach different floors with minimum delay. 33. Fire Load Calorific energy, of the whole contents contained in a space, including the facing of the walls, partition, floors and ceilings. 34. Fire Load Density The fire load per unit area. 35. Fire Point Is the lowest temperature at which the heat from the combustion of a burning vapour is capable of producing sufficient vapour to enable combustion to be sustained.
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36. Fire Prevention The whole set of precautions to prevent the outbreak of fire and to limit its effects. 37. Fire Protection Design features, systems or equipment in a building, structure or other fire risk, to minimise the danger to persons and property by detecting, containing and/or extinguising fires. 38. Fire Resistance Fire resistance is a property of an element of building construction and is the measure of its ability to satisfy for a stated period some or all of the following criteria: (a) Resistance to collapse (b) Resistance to penetration of flame and hot gases, and (c) Resistance to temperature rise on the unexposed face upto a maximum of 180oC and / or average temperature of 150oC 39. Fire Resistance Rating The time that a material or construction will withstand the standard fire exposure as determined by fire test done in accordance with the standard methods of fire tests of materials/ structures. 40. Fire Separation The distance in meters measured from the external wall of the building concerned to the external wall of any other building on the site, or from other site, or from the opposite side of street or other public space to the building for the purpose of preventing the spread of fire. 41. Fire Separating Wall: The wall provides complete separation of one building from another, or part of a building from another part of the same building, to prevent any communication of fire or heat transmission to wallitself which may cause or assist in the combustion of materials on the side opposite to that portion which may be on fire.
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and open to the outer air.) and the construction is undertaken by one Agency/Authority.Handbook on Building Fire Codes 42. all buildings 15m and above in height shall be considered as high rise buildings. IITK-GSDMA-Fire 05-V3. High Rise Building As per NBC Part-4. ceilings and the like as per the laid down criteria. Gallery An intermediate floor or platform projecting from a wall of an auditorium or a hall providing extra floor area. Fire Tower: An enclosed staircase which can only be approached from the various floors through landings or lobbies separated from both the floor areas and the staircase by fire-resisting doors. etc. 45. Fire Stop: A fire resistant material or construction having a fire resistance rating of not less than the separating elements installed in concealed spaces or between structural elements of a building to prevent the spread/propagation of fire and smoke through walls. Flash Point Is the lowest temperature at which the vapour produced by a substance will flash momentarily when a flame is applied. 48. It shall also include the structures provided for seating in stadia. 43. where land is owned jointly (as in the case of co-operative societies or the public agencies.0 Page 13 . additional seating accommodation etc. Group Housing Group or multi-storeyed housing for more than one dwelling unit. Floor Area Ratio The quotient obtained by dividing the total covered area (plinth area) of all floors by the area of the plot. FAR = Total covered area of all floors Plot area 46. 44. 47. such as local authorities or housing boards.
IITK-GSDMA-Fire 05-V3. 51. Latent Heat The thermal energy or the heat of a substance absorbed when it is converted from a solid to a liquid. Latent Heat of Fusion The heat which is absorbed during change of state from solid to liquid is called the latent heat of fusion.Handbook on Building Fire Codes 49. is called latent heat. It is measured in Joules per unit mass(J/kg). Inhibition A process of fire extinguishment in which the extinguishing agent used prevents the development of chemical reactions in the flame initiating and sustaining the fire. Interior Finish Generally consists of those materials or combinations of materials that form the exposed interior surface of walls and ceilings. 53. Latent Heat of Vapourisation The heat which is absorbed by a liquid for conversion to its vapour stage is the latent heat of vapourisation for that liquid. 55. 54. Liquefied Gases Are gases which. or from a liquid to a gas / vapour. When ice melts to form water and heat is absorbed. The heat which is absorbed by water for conversion to steam is the latent heat of vapourisation of water. it is called as the latent heat of fusion of ice. as long as any liquid remains in the container. 50. 52. at normal atmospheric temperature inside the container exists partly in the liquid state and partly in the gaseous state and under pressure. Horizontal Exit An arrangement which allows alternative egress from a floor area to another floor at or near the same level in an adjoining building or an adjoining part of same building with adequate fire separation.0 Page 14 .
registered Charitable Trusts or such other organisations for their non-profitable public activities. 60. Mezzenine Floor An intermediate floor. semi-government organisations. accessible only from the lower floor 58. Means of Egress A continuous and unobstructed way of travel from any point in a building or structure to a place of comparative safety. 63. IITK-GSDMA-Fire 05-V3. an occupancy shall be deemed to include subsidiary occupancies which are contingent upon it. 62. Occupant Load The number of persons for which the means of egress of a building or a portion thereof is designed. Occupancy or Use Group The principal occupancy for which a building or a part of a building is used or intended to be used. 59. Plenum An air compartment or chamber to which one or more ducts are connected and which forms part of an air distribution system. between two floors. amplifiers. Plinth Area The built-up covered area measured at the floor level of the basement or of any storey.Handbook on Building Fire Codes 56. Public Address System (PA System) The complete chain of sound equipment (comprising essentially of microphones. 57. above ground level. 64. Public Building A building constructed by government. public sector undertakings. and loud speakers) required to reinforce the sound emanating from a source in order to provide adequate loudness for comfortable hearing by the audience. Pyrolysis Irreversible chemical decomposition of a material due to an increase in temperature.0 Page 15 . 61. For the purpose of classification of a buliding according to the occupancy.
by walls. partitions. physically separated(eg. lobby escape route. 73. (J/kg per oC) 71. Pressurisation The establishment of a pressure difference across a barrier to protect a stairway.0 Page 16 . Stairway (Enclosed) A stairway in a building. 69. Specific Heat The heat energy required to raise the temperature of unit mass of a substance through 1oC is the specific heat of the substance. but not necessarily a protected stairway. Protected Shaft A shaft which enables persons. Pressurisation Level The pressure difference between the pressurised space and the area served by the pressurised escape route. 66. screens. 70. Smoke A visible suspension in air of a mixture of gaseous and particulate matter resulting from combustion or pyrolysis. expressed in pascals(Pa) 67. and which is enclosed with fire resisting construction. Stairway (Protected) A stairway having the required degree of fire protection and forming the vertical component of a protected escape route or means of egress. or room of a bulding from smoke penetration. The exit shall have adequate cut-off within the building from staircase below. IITK-GSDMA-Fire 05-V3. barriers etc. Roof Exits A means of escape on to the roof of a building where the roof has access to it from the ground.Handbook on Building Fire Codes 65. 72.) from the accommodation through which it passes. 68. air or objects to pass from one compartment to another. Refuge Area An area where persons unable to use stairways can remain temporarily to await instructions or assistance during emergency evacuation.
an exhibition hall. chimney or enclosure. (i) is structurally unsafe. stadium. (ii) is insanitary. Ventilation: Supply of outside air into. lecture hall. Unsafe Building A building which. (iii) is not provided with adequate means of egress. marriage hall. (iii) An Institutional Building. dilapidation or abandonment. This stack effect plays a vital role in smoke movement. community hall. motion picture.Handbook on Building Fire Codes 74. Stack Pressure Pressure difference caused by a temperature difference creating an air movement within a duct. town hall.0 Page 17 . 79. theatre museum. or the removal of inside air from an enclosed space. (v) A Storage Building (vi) A Multi-purpose Building or Multiplex 75. Special Building (i) A building solely used for the purpose of a drama or cinema theatre. external escape route or final exit. and (vi) in relation to its existing use constitutes a hazard to safetly or health or public welfare by reasons of inadequate maintenance. Stack Effect Is the vertical natural air movement from the building caused by the differences in temperature and densities between the inside and outside air. a drive-in theatre. IITK-GSDMA-Fire 05-V3. 76. (v) is dangerous to human life. 78. 77. Travel Distance The distance to be travelled from any point in a building to a protected escape route. (iv) constitutes a fire hazard. (ii) A Hazardous Building. (iv) An Industrial Building. an assembly hall or auditorium.
82. IITK-GSDMA-Fire 05-V3. fire fighting operations are facilitated and minimum fire damage is caused. 81. Wet Riser An arrangement for fire fighting within the building by means of vertical rising mains of not less than 100 mm diameter with landing valves on each floor/landing for fire fighting purposes and permanently charged with water from a pressurised supply.Handbook on Building Fire Codes 80. Venting Fire The process of inducing heat and smoke to leave a building as quickly as possible by such paths so that lateral spread of fire and heat is checked. Volume to Plot Area Ratio (VPR) The ratio of volume of building measured in cubic metres to the area of the plot measured in square metres and expressed in metres.0 Page 18 .
whereas wood floats on water. Some substances are heavier than others. VD of gases and vapours are compared with the density of dry air. Relative density or specific gravity = mass of any volume of the substance mass of an equal volume of water (The specific gravity of water is taken as 1 at 4oC) Vapour Density. These states are interchangeable by alteration of the temperature and pressure exerted on them. as ice(solid state) at 0o C. which is the lightest gas.BASIC PRINCIPLES OF COMBUSTION 1.. for ease of practical application. and as vapour above 100o C. Water has a density of 1g/cm3.3 The ratio of the mass of any volume of a solid or a liquid substance to the mass of an equal volume of water is known as relative density or specific gravity. 1. for fire service purposes.0 Page 19 . The following are the VDs of a few gases as compared with air: IITK-GSDMA-Fire 05-V3.1 Matter can exist in three states-solid. However. liquid or gas/vapour.The vapour density(VD) of a gas or vapour is generally denoted in relation to the density of equal volume of hydrogen. water can exist in all three states-liquid at normal temperature. 1.FIRE SCIENCE BASIC PRINCIPLES CHAPTER -1. This is because wood has a lower density(mass per unit volume) than iron. which is 1.2 Matter possesses mass and occupies space. For eg: Iron sinks in water.Handbook on Building Fire Codes HANDBOOK ON BUILDING FIRE CODES SECTION 3 . Density of a substance can be calculated by dividing the mass of the substance by its volume: Mass Density = Volume Density is measured in kg/m3 or g/cm3. For instance.
1. 1.07 1. it will accumulate at lower levels and will present a serious fire and explosion hazard. Water miscibility of the liquid is also a matter to be reckoned with. and hence. the density or specific gravity of a burning liquid determines partly whether water can be used as a extinguishing agent on it.4 Density of liquids and gases have a significant bearing on fire protection technology applications. Melting Point (MP) is the temperature at which a solid melts. If propane(C3 H8). The MP. it is lighter than air. of some substances are listed below: IITK-GSDMA-Fire 05-V3. it is heavier than air and will tend to sink.Handbook on Building Fire Codes Gas/Vapour Hydrogen Methane Ammonia Carbon-di-oxide Chlorine Petrol V.0 Page 20 .47 2.D as Compared with Air lighter 0.6 1.5.556 than air 0. Freezing point and Boiling point 1. and will tend to rise. For instance. It is a well known fact that petrol and other flammable liquids float on water.5.5 Melting point. water jets which are effective for extinguishing ordinary fires will be ineffective in extinguishing a burning petrol tank fire.2.53 2. If it has negative buoyancy. the density of a gas or vapour determines whether it will be accumulating at higher or lower levels of a building. The temperature at which a liquid turns into a solid is termed as its Freezing Point(FP).The temperature at which a liquid boils and becomes a vapour is the Boiling Point(BP) 1. These two temperatures are identical for the same substance. the main component of Liquid Petroleum Gas(LPG). Likewise. If a volume of a gas has positive buoyancy.5 heavier than air 0. leaks from a cylinder.
The heat energy required to raise the temperature of unit mass of a substance through 1oC is referred to as specific heat capacity of the substance(J/kg per oC). Specific heat capacities of some substances are given below: Substance Steel Aluminium Copper Ice Methylated Spirit Water Specific Heat Capacity(J/kg per oC) 460 900 400 2100 2400 4200(4. This phenomenon is called evaporation.5.6.Handbook on Building Fire Codes Substance Aluminium Steel Sulphur Cast Iron Glass Carbon MP(approx) 650oC 1382oC 109oC 1200oC 1300oC 3600oC(C has the highest MP) 1. Low specific heat capacities are of considerable importance in promoting fire risks. 1.3 Materials with a low specific heat capacity will heat up more rapidly in a fire situation than those of high specific heat capacity.0 Page 21 . 1.6.2kJ/kg) per oC.2 kJ/kg/oC) 1.1 When heat is applied to a body.2. its temperature rises..3kPa) 1.6. viz. The liquid boils when the saturation vapour pressure equals atmospheric pressure(101.3. This is one of the reasons why water is effective as an extinguishing agent.4.6 Specific Heat 1. Even below the boiling point some molecules of the liquid may reach the surface and escape into the surrounding air. 4200j/kg(4.6. Alcohol etc. IITK-GSDMA-Fire 05-V3. The specific heat capacity of water is unusually high. Petrol. have low specific heat capacity and also vaporise readily.
2. Latent heat: A substance absorbs heat when it is converted from a solid to a liquid. Solid expands when heated.8. unless prevented by some external cause. Likewise. This is the main reason why water is chosen as an extinguishing agent. It takes 336 kJ to convert 1kg of ice at 0oC to water at the same temperature. when water at 0oC freezes to form ice. Gases expand about 100 times more than liquids. Other substances also exhibit the same phenomenon of absorbing latent heat when they melt. the temperature remains constant at 100oC. and giving out latent heat on solidifying. approx. Thermal expansion 1. 1.7. This is called the latent heat of fusion of ice. 1. the temperature of the water goes on rising until it reaches 100oC. the BP of water.Handbook on Building Fire Codes 1. Ice melts to form water and heat is absorbed.2. 2260kJ/kg. or from a liquid to a gas/vapour. breadth and thickness. It is measured in Joules per unit mass(J/kg).7.1 When a container with water is heated. The amount by which unit length of a solid substance expands when its temperature is raised by 1 degree is called the co-efficient of linear expansion of the substance. the same quantity of heat is given out for every 1kg of ice formed. although heat continues to be applied to the container.1 A substance expands when heated. This thermal energy is called latent heat.8. increasing in length. At this temperature the water boils.0 Page 22 . The typical values of linear expansion for a few other solids are: IITK-GSDMA-Fire 05-V3. the co-efficient of linear expansion is 0. 1. The heat absorbed by water while evaporating from the surface of a burning solid reduces its temperature as well as the rate of pyrolysis.000012 peroC. in all three dimensions.8. For steel. The latent heat of vaporisation of water is extremely high. 1. and ultimately achieves extinguishment of the fire. More often the increase in length is more predominant. On heating liquids expand about ten times more than solids. Heat is absorbed during the change of state from solid to liquid also. However.7. This heat which is absorbed by water for conversion to steam(vapour stage) is what is known as latent heat of vaporisation of water.
or even leading to collapse. provided its volume is kept constant.9.000017 per oC 0. It is expressed as: Vi V2 = Ti T2 b) Boye's Law: The volume of a Gas is inversely proportional to the pressure upon it provided the temperature is constant. in the case of gases. there are three variables involved in thermal expansion process .3. It is expressed as: P1 P2 = T1 T2 d) The General Gas Law: The above three Gas Laws can be combined and expressed in a single equation: IITK-GSDMA-Fire 05-V3.0 Page 23 . provided its pressure is kept constant. It is expressed as : V2 P1 = and P1 V1= P2 V2 V1 P2 c) Law of Pressures: The pressure of a given mass of gas is directly proportional to its absolute temperature. In other words.1. 1. The heat on the inner side of a wall of a burning building may cause it to expand at a higher rate than the other side. thus causing the wall to bulge outwards.000012 per oC This thermal expansion phenomenon has to be kept in view for building design and construction. More than in solids and liquids.temperature. Thus. thermal expansion is more apparent in gases. pressure and volume.9. Gas Laws: Gas particles more freely and fast and can produce significant effects if their temperature volume or pressure are changed.000023 per oC 0. These changes are expressed in what are known as Gas Laws. volume of a given mass of gas increases by 1/273 of its volume at 0oC for every 1oC rise its temperature provided the pressure remains constant. and is quite relevant while a building gets involved in fire. Hence the pressure exerted by a gas increases when heated.Handbook on Building Fire Codes Copper Aluminium Concrete - 0. Gases and Gas hazards. 1. 1. and are explained below: a) Charles Law: The volume of a given mass of gas is directly pro portional to its absolute temperature.8.
CO2.. CO2. but usually slightly above their BP at NTP. 1. He.. Cl2 (iv) Inert Gases . H2. N2... C2H2. N2 (iii) Reactive Gases . CO..Eg. chemical processing. refrigeration etc. O2. Liquified Petroleum Gases(LPG). Propane. Methane (C3H8. as long as any liquid remains in the container) Eg.9. and at correspondingly low to moderate pressures.Eg. Ar. N2.2.. IITK-GSDMA-Fire 05-V3.Eg. Classification of Gases (a) Classification by chemical properties: (i) Flammable Gases .Eg. H2S. SO2 (b) Classification by physical properties: (i) Compressed Gases (which exist solely in the gaseous state under pressure at normal atmospheric temperature inside the container) Eg. Air (BP _194.. NH3. O2(BP_183oC) (c) Classification by usage: (i) Fuel Gases . F2 (most reactive). (ii) Liquefied Gases (which. welding and cutting. CH4) (ii) Non-flammable Gases . SO2. at normal atmospheric temperatures inside the container. which exist in the container at temperatures far below normal atmospheric temperature.Handbook on Building Fire Codes P1 V1 P2 V2 = T1 T2 e) It is important to note that when the temperature and pressure levels of liquifaction point are attained. and under pressure. the Gas Laws are no longer applicable.) Eg. NH3. LPG (ii) Industrial Gases (Comprising entire range of gases utilised for industrial processes.Eg. exists partly in the liquid state and partly in the gaseous state.Eg. N2 (v) Toxic Gases . Eg..0 Page 24 . Liquified Oxygen(LOX) (iii) Cryogenic Gases (liquified gases. Cl2. Natural Gas(NG)..4oC). O2.
respiratory therapy etc. can mix with air. Flammable vapours. Transfer of heat governs all aspects of fire.Handbook on Building Fire Codes (iii) Medical Gases (Anaesthesia. Under fire conditions. 1.10. including LPG.0 Page 25 .3. with great damage potential. meaning Boiling Liquid Expanding Vapour Explosion. and when in correct proportions. O2.Containers can fail due to metal fatigue. liquifiable gases are more hazardous than permanent gases. from ignition through to extinguishment. (ii) Convection or (iii) Radiation.1 Heat is transferred from regions of higher temperature to regions of lower temperature. and can result in explosion. (i) Conduction (ii) Convection (iii) Radiation Fig-1 Showing methods of Heat Transmission (i) Conduction (ii) Convection (iii) Radiation IITK-GSDMA-Fire 05-V3. meaning Unconfined Vapour Cloud Explosion. Transmission of Heat 1. in containers/vessels.10. can result in violent explosion known by the term UVCE. (b) Hazards of fire . BLEVE. 1. can result in violent explosion. The primary hazards of gases arise from: (a) Hazards of confinement .(i) Conduction. when released into the air. Flammable liquids.Gases expand when heated leading to pressure increase resulting in gas release and (or) container failure. This transmission or transfer of heat is achieved through three methods . a phenomenon known by the term. which has immense damage potential. N2O. when exposed to fire.) Eg.9.
good conductors of electricity are good conductors of heat also. The conductivity of building materials has an important role in the fire resistance capability of elements of structure.0 Page 26 . thermal conductivity is relevant in terms of the danger of fire spread. Most metals are good conductors. or the ability to conduct heat.Handbook on Building Fire Codes (a) Conduction (i) Solids are better heat conductors than liquids or gases. whereas a wooden door will not. (ii) In fires. A steel beam passing through a wall can be the cause of fire spread from one room to another. the best conductors being silver and copper. Convection also causes the up-draft in chimneys or the 'stack effect'. since wood is a poor conductor. varies between materials. and vice-versa. (b) Convection (i) Convection requires a circulating medium for transmission of heat and occurs only in liquids and gases. Thermal conductivity. Convection is used in domestic heating systems or radiators. Generally. It transports the enormous amount of chemical energy released during a fire to the surrounding environment by the movement and circulation of hot gases. Fig-2 Fire spread in a building due to Conduction of heat along an unprotected steel beam/girder A plain metal door can conduct heat from one side to another. IITK-GSDMA-Fire 05-V3.
radio waves.90%) released in the combustion process. Roughly. It is through the same method by which heat from the sun passes through the empty space to warm the earth. upward travel of hot gases Fig-3 Showing how fire on a lower floor can spread to upper floors by convection (c) Radiation (i) Radiation is a form of energy that travels through a space without an intervening medium. such as a solid or a fluid. The rest of the heat is transmitted as radiation. H2O and CO2. (ii) In a fire. When it falls on a body.0 Page 27 . all electro-magnetic waves travel at the speed of light (300. convection currents can convey hot gases and smoke upwards through stairwells and open lift shafts. Some radiation also comes from the gaseous combustion products. It travels as electromagnetic waves. about 10% of the heat of combustion is lost IITK-GSDMA-Fire 05-V3.). reflected and / or transmitted. spreading the fire to the upper floors through open doors and false ceilings. the hot gases rise vertically upwards in a plume that carries with it most of the heat(70% . and x-rays. In a vacuum. depending upon the fuel.000 km/sec. similar to light.Handbook on Building Fire Codes (ii) In a multi-storey building fire. it can be absorbed.
IITK-GSDMA-Fire 05-V3. the intensity is one-ninth. Water vapour and CO2 in the atmosphere. 2m 2m 1m 2m 2m 1m 2m 2m Fig-4 Showing the inverse square law in radiation (iv) Radiation has been the cause for many fires. This is the reason why fire fighters normally enter a burning building or room with hose handlines fitted with water spray/fog nozzles. But the intensity of radiation decreases with distance. and so on. Water droplets are capable of absorbing almost all the incident infra-red radiation thereby cooling to surroundings. intensity becomes one quarter. A common cause of home fires is clothing getting ignited by radiant heat when it is placed too close to a source of radiation. This is the reason why forest fires or large LNG fires are relatively less hazardous when humidity is high.Handbook on Building Fire Codes from the flame by radiation in these cases. larger fires involving ordinary fuels may release 30 to 50 percent of the total amount of energy as radiation. This is known as the inverse square law of radiation. absorb appreciable amount of thermal radiation emitted from large fires. at three times the distance.0 Page 28 . Twice the distance. which will generally be present in fires. (iii) All forms of radiant energy travel in straight lines. However. exposing nearby surfaces to high levels of radiant heat transfer.
Handbook on Building Fire Codes Fig-5 Clothing can get ignited if placed too close to a source of radiation Similarly. which acts as a lens. IITK-GSDMA-Fire 05-V3. had also been the cause of fires. radiant heat from the sun passing through a glass window or a bottle.0 Page 29 .
(a) The heat of a chemical reaction is the energy that is absorbed or emitted when a given reaction takes place. the new substances formed contain more energy than the reacting materials. Exothermic reactions produce substances with less energy than was in the reacting material. a gas phase fuel.2 . actually involves many intermediate steps(elementary reactions).3. the hyroxyl radical (OH). 2. Combustion is an exothermic. The reaction stated above. 2. Free radicals include atomic Hydrogen(H).3. (comparatively slow oxidation) generally occurs as glowing combustion or smouldering. The process is usually associated with the oxidation of the fuel by atmospheric oxygen with the emission of light.Handbook on Building Fire Codes CHAPTER. which create a chain reaction. and many more.COMBUSTION PROCESS (RELEVANT TO FIRE SCIENCE) 2. Condensed phase combustion.phase fuel. In endothermic reactions. COMBUSTION 2. so that energy in the form of heat is released by the reaction. They are mostly vapour phase reactions or reaction between two or more gases. (b) All reactions get faster as the temperature is increased. one of which usually is Oxygen.0 Page 30 . while gas phase combustion (representing rapid rate of reaction) usually occurs with a visible flame(flaming combustion). though appears simple. self sustaining reaction involving a condensed .2 Heat of Reaction . and so energy in the form of heat is absorbed by the reaction.1. the speed of chemical reaction doubles for every 10 oC rise of temperature. As a rough rule. IITK-GSDMA-Fire 05-V3.1 Chemical Reaction A chemical reaction is a process by which reactants are converted into products. Thus the oxidation of propane is represented by the equation C3H8 + 5O2 = 3CO2 + 4H2O The mechanism in the above reaction is quite complex and involves reactive species called free radicals. Oxygen(O). or both. Some over-exo-thermic reactions are of direct concern to fire service.
and (ii) Diffusion flame in which combustion takes place in the regions where the fuel and air are mixing.Handbook on Building Fire Codes 2. as in the combustion of carbon. The rate of diffusion of the reacting gases to some extent controls the size of the flame. Basically. such as most combustible solid organic materials and flammable/combustible liquids. Fuels which can be oxidised comprise of numerous materials.3.4.(i) Pre-mixed flame in which gaseous fuel is mixed intimately with air before ignition. The reactions can be maintained in a flame only when sufficient heat is being transferred to the unburned gases to raise them to flame temperatures(commonly between 1500 oC to 2000oC) 2. Fig-6 A diffusion flame Fig-7 A premixed flame 2. Nearly all the flames seen by the fire fighters are diffusion flames.3. Oxidation Reactions: To the fire fighter. Eg: Candle flame. the term oxidation means a combination of substance with O2. Sufficient thermal energy is released in the combustion process.0 Page 31 . The flame becomes luminous because of the presence of carbon particles.3. Oxidation reactions involved in fires are complex and exothermic.3. A flame is the visible part of an exothermic vapour . IITK-GSDMA-Fire 05-V3. There are two types of flaming combustion . which consist primarily of carbon and hydrogen.2.phase reaction zone. more often with turbulence. a combustible material (fuel) and an oxidising agent(more often air) are essential requirements for an oxidation reaction to take place.
There have been several cases of cotton waste smeared with linseed oil or paint igniting in a few hours. Ignition can be caused by the introduction of small external flame. generating heat which increases the rate of reaction.5 For most combustible solids and liquids.is the lowest temperature at which the heat from the combustion of a burning vapour is capable of producing sufficient vapour to enable combustion to be sustained. nitrogen and some other gases without oxygen being supplied.6. it is called auto-ignition.is the lowest temperature at which the vapour produced by a substance will flash momentarily when a flame is applied. Generally. initiation of the flame reaction occurs in the gas or vapour phase.3. Once ignition has started. 2.7 Fire Point .5 Certain combustible materials such as pyroxylin plastics contain their own oxygen so that partial combustion may occur without oxygen from any external source. Flash Point . Certain organic materials can react with oxygen at room temperatures. 2. it will continue until all the available fuel and /or oxidant has been consumed. spark or glowing ember when it is known as piloted-ignition. or until the flame is extinguished. Eg. 2. carbon-di-oxide.9. Usually the piloted ignition temperature of a substance is considerably lower than its auto ignition temperature. Linseed Oil has the property of reacting with atmospheric oxygen.1. IITK-GSDMA-Fire 05-V3. 2.0 Page 32 .8 Spontaneous Ignition Temperature / Auto Ignition Temperature .is the lowest temperature at which a substance will ignite spontaneously or by itself without any external source of ignition. 2. Ignition is the process of initiating self-sustained combustion. the solids and liquids have to be heated for generation of combustible vapour-air-phase mixture. Exceptions to this are carbon and certain metals where direct surface oxidation occurs. 2.9 Spontaneous Combustion 2.4. When it occurs without the assistance of an external source. Combustion may also occur in certain special cases in an atmosphere of chlorine.Handbook on Building Fire Codes 2.
Oily rags high high bulk bales 2.10. Such heating can initiate oxidation reaction may result in ignition within three to six weeks of storage.1 A combustible or flammable gas or vapour . drums keep dry. Thermal insulation factor plays an important role in causing spontaneous combustion. Menhaden Oil 7. Table showing the list of substances liable to spontaneous combustion is given below.9. or IITK-GSDMA-Fire 05-V3.2. Supply ventilation no contact with rags etc. Flammability Limits(F.Handbook on Building Fire Codes especially in confined conditions. Action of bacteria on certain organic materials and agricultural products like wet or improperly cured hay can also result in spontaneous combustion. avoid contact wet rags. bags containers barrels. This kind of ignition is known by the term spontaneous combustion. cotton or other fibrous combustible materials -doavoid storing in bulk in open 4.Charcoal 2. 2. Iron pyrites 5. tank cars 6. Fish oil high high high bulk. keep dry and cool. avoid contact of leakage with rags etc. powdered or pulvurised coal or some metal powders are also prone to spontaneous combustion.air mixture can burn in air only if the mixture is within certain proportions.L) 2. Linseed oil moderate high bulk drums.0 Page 33 .10. Table-1 SUBSTANCES LIABLE TO SPONTANEOUS COMBUSTION Substances Tendency Method of Storage Precautions 1. Likewise. Cod liver oil 3.
and will not burn. These limits are referred to as lower and upper limits of flammability (flammable limits or FL) for the substance.4% 12. Sometimes these limits are also called as lower and upper explosive limits. A Table showing the Flash Point (FP). Benzene 5.3% 1. Auto Ignition Temperature(AIT) and Flammable Limits(FL) of certain chemicals is appended below: Table-2 FP.9% 8. Acetylene 3.8oC _ o 9C _ o 60 C _ 104oC _ o 20 C _ 42. the mixture is said to be a rich mixture. and it will not burn.10.8 651oC 335oC 535oC 535o 585oC 430oC 473oC 650oC 16% 2% 2.2. 2. Ether 245oC 180oC 1. Ammonia 2.3% 22% IITK-GSDMA-Fire 05-V3. Similarly. Hydrogen 6. Cyclohexane 10.5% 35% 85% 13% 8% 74% 8. the mixtrue is said to be a lean mixture. If the proportion of the gas/vapour in air is too little.5% 74% 8. Butane 7.Handbook on Building Fire Codes limits. Propane _ 17.7oC _ 17. AIT AND FL OF CERTAIN CHEMICALS Chemical FP AIT Lr FL Ur 1.5% C1.5% 9. if the proportion of gas/ vapour in air is too much.0 Page 34 .9% 2. Acetone 4. Carbon Monoxide (CO) 9.5% 4% 1.
5% 6% 12.11.8oC to 38oC 3. the lower limits can be slightly lowered still further.10. for chemicals are not very rigid. Oxidation in its most simple form is combination of a substance with oxygen.that is. which is also oxidation. The above values. There are variable factors which may slightly alter the values. increase in temperature and pressure can make the flammable limits slightly elastic . Kerosene 19.% 40% 482oC 1. 0. 2.6% 19.7% 112. Oxidising agents 2.5% 5.7% spontaneously) 2.6oC 246oC to 456oC 371o .8oC 13. dimensions of container. H2S 20.P. Sulphur(S) 18.11. Hydrocyanic Acid(HCN 14. Ethyl Alcohol 12. The factors which influence FL are pressure. Petrol _ 45. flame propagation.3. or the upper limit can be raised slightly.1% 4.5oC 207oC 31oC 32oC 125oC 1% 50% 552oC 232oC 227oC 270oC 1. Certain elements other than oxygen also act as oxidising agents.427oC 538oC 1. and moisture content of the mixture. Carbon-di8C sulphide (CS2) 16.8oC _ 17.5% 4% 6. IITK-GSDMA-Fire 05-V3.0 Page 35 . Hydrazine (N2H4) 4. For instance.Handbook on Building Fire Codes Chemical FP AIT Lr FL Ur 11. especially FL.8% _ o 15.1.3% M. most metals will react with chlorine or other halogens.8oC 9% 44% 100% (May ignite 4. Naphtha _ 17. Toluene 17. temperature. For instance.
besides organic nitrates. Eg. 2. and the vapour density(VD) is around 1. There are numerous combustible organic substances. are also strong oxidising agents. which is commonly used cooking gas. Methane(CH4). inorganic nitrates. but are highly explosive also. organic peroxides and hyperoxides. (b) Aromatic compounds. Apart from some acids.13. It is estimated that there are over a million such carbon compounds.Handbook on Building Fire Codes Eg: Mg +Cl2 = Mg cl2 ( Cl2 acts as an oxidising agent) 2.11.12. Organic chemicals are of two classes: (a) Aliphatic compounds (paraffins). both being highly flammable gases. which contains chains of carbon atoms. which are essentially carbon compounds.0 Page 36 . the gas/vapour collects at the lower levels. Ethane(C2H6). which are also powerful oxidising agents. 2. IITK-GSDMA-Fire 05-V3. Some of them are not only flammable. The expansion ratio of liquid to gas of LPG is approx. 1 to 270. Propane(C3H8) etc. Toluene(C7H8) etc.5 to 2. Liquefied Petroleum Gas (LPG). and in case of leakage. like Nitric acid. nitro-compounds. permanganates. Benzene(C6H6). peroxides etc. Eg. which contain rings of carbon atoms.2.. is a mixture of propane(C3H8) and butane(C4H10). Perchloric acid etc.
Br2.(i) Gunpowder (charcoal + any oxidising agent like pot. Oxidising Agents . Alkalis. (ii) Thermite (Al + Fe oxide) which is used in thermite bombs (iii) Nitrous oxide (N2O) or laughing gas.5. Tear gas. the fire fighting party will be exposed to considerable danger from poisonous fumes and gases (a) Irritants:-Cl2. Certain chemicals which have O2 content in them and in case they catch fire they will burn without the aid of air or O2. 2.A chemical fire is a fire in which the material is a chemical.CO (c) Injurious by touch or contact . chlorate) which is very sensitive to shock and heat. dissolve and cause danger to IITK-GSDMA-Fire 05-V3.0 Page 37 .14. but can be liquified by the application of pressure since their critical temperatures are well above room temperature(critical temperatures propane and butane are 96. If there is a rise in temp. Chlorates.14.When fighting chemical fires.Handbook on Building Fire Codes 2.Chlorates or other oxidating agents when mixed with water used for fire fighting. 2.1. Hydrocyanic acid gas (d) Danger of fire spread .Acids. I2. Chemicals which contain O2 and highly flammable are: a) Solitary compounds: Such as celluloid (cellulo-nitrate).14. Phosphorus. NH3 (Ammonia) (b) Toxic . or due to any reason spark falls on them. Chromates etc. Permanganates. nitro-glycerine. Combustible materials + a supporter of combustion (which may not be O2) such as Cl2. They are compounds of C. 2. 2. These are gases at room temperatures and pressures. they catch fire. LPG cylinders heated above the critical temperature are likely to explode due to enormous pressure increase.1.6. Chemicals which in contact with organic substances react easily .Nitrates. Chemical fires 2.7 o C and 152 o C respectively). 2.3. Peroxides.Eg: acid. S. Risks at chemical fires . of the halogen group.14. N&O2 b) Mixtures .14. H2.13.14. 2.14.4. 2. Hence they are highly dangerous in storage.
Never use ferrous tools (which cause sparks) to open sealed drums of Cal. liberates O 2 and generates heat which can iginite surrounding combustible materials.Reacts with water and produces acetylene gas which is highly flammable. Large quantities of steam are also produced. Water is not normally used on flammable liquids whose specific gravity is less than water itself . Walls of the godowns should be thick. dissociate water into its elements with generation of heat. 2. starts burning and causes fire to other stores.With moisture of water. when gets exposed to air. 2. carbide. (c) Cal. but water could be successfully used on it. There are some others on which water should not be used as an extinguishing medium.At certain temperatures.A list of substances on which use of water is restricted is given in Table-3. Carbide . (b) Calcium Oxide (Quick lime) Water on cal. oxide results in generation of heat which is enough to ignite nearby materials. which is normally kept under water. In tackling oil fires -use jet of water with discretion to cool down drums (and surroundings) which are near the fire. Petrol). (d) Sod. The state of reaction for certain metals when in contact with water is shown under Table-3. Peroxide . since they are lighter than water.1. IITK-GSDMA-Fire 05-V3. and use foam on fire itself.0 Page 38 . carbide godowns should be away from other stores. There are certain metals which react with water even at ordinary temperatures. Leaky drums may contain acetylene gas produced by reaction of the chemical with moisture and one spark caused by ferrous tools might cause an outbreak of fire. danger is more.(eg. different metals react with water. Phosphorus(P). Cal.15. and O2 is a supporter of combustion. When these metals are in powder form. Finely divided water spray is also efficacious on small oil fires. (a) Metals:. Carbon-di-sulphide (CS2) has specific gravity more than water and is flammable.Handbook on Building Fire Codes other stores nearby. thereby promoting combustion. (e) Other Substances . There are some substances which react with water.15 Chemicals on which use of water is restricted.
0 Page 39 .Handbook on Building Fire Codes Table-3 METALS WHICH REACT WITH WATER Metals State of Temperature Metal Potassium Sodium Barium Strontium Calcium Magnesium Aluminium Zinc Iron Manganese Lead Copper Tin Water Cold Cold (a) burning (b) red-hot (a) cold (b) Steam no appreciable action no appreciable action IITK-GSDMA-Fire 05-V3.
2. Triangle of fire 2.0 Page 40 . Unlike slow oxidation. Combustion usually involves an exothermic chemical reaction between a substance or fuel and oxygen. a combustion reaction occurs so rapidly that heat is generated faster than it is dissipated. oxygen(or air) and a combustible substance (or fuel). causes and sources of ignition. 2. causing a marked increase of temperature. Fire or combustion will continue as long as these three factors are present. even upto a few hundreds of degrees. the temperature reaches so high that visible light or flame is generated.FIRE EXTINCTION / SUPPRESSION TECHNOLOGY CHAPTER -1.CONSTITUENTS OF FIRE 1. (old concept) IITK-GSDMA-Fire 05-V3. 1. One way of discussing fire or combustion is in terms of the 'triangle of fire' or combustion. Removal of one of them leads to the collapse of the triangle and the combustion process stops. Combustion Process 1. heat.1. It has been seen that for combustion to occur three factors are essential.Handbook on Building Fire Codes SECTION 4 .1 An understanding of the basic principles of combustion or fire. Very often. fire growth and fire spread is necessary for understanding the principles of fire control and extinguishment. Fig-8 Triangle of Fire showing the three constituents of fire.
A small decrease in temperature causes a disproportionately large decrease in the rate of the reaction.2. is a type of chain-reaction. therefore. A form of chemical reaction is set-up in the layer of gas adjacent to this source with the result that heat and what are called 'chain carriers' pass into the next layer of gas and continue the cycle of the operations there.2 Nature of flame 2. Combustion. Chain carriers are believed to be atoms or part of molecules. A single H atom.Handbook on Building Fire Codes 2. Fig-9 Uninhibited / Unbroken Chain Reaction showing active radicals like H*. known as 'free radicals' and these are extremely reactive. As has been stated. O* & OH* in the flame 2.0 Page 41 .2. The flame temperature is very important because the rate of a key combustion reaction (H+O2 = OH+O) is very sensitive to temperature.1. rather like runners in a relay race.2. the burning of most materials produce a flame. when introduced into an H2-O2 mixture at an elevated IITK-GSDMA-Fire 05-V3. A flame front stemming from a local ignition source is established in a flammable medium.
(ii) Adding a chemical inhibitor to interfere with the chain reaction.2. H is present in the vast majority of combustibles except for metals and pure carbon. O and OH species recombine according to the reaction H+O = OH and H+OH = H2O Similar chain reactions occur in flames of any H containing fuel. The flame temperature is generally around 1900oC and above.4. In other words. there are two fundamental ways of reducing combustion intensity in a flame.2. flame is unable to continue burning. 2. 2.0 Page 42 . which continues until the reactants are consumed. Thus. below a critical temperature (1200oC to 1300oC). smoke is generated. ultimately causing extinguishment: (i) Reducing the flame temperature. carbon monoxide is also formed due to incomplete combustion. 2. resulting in a branching chain reaction. By bringing the flame temperature to below around 1200oC to 1300oC. the organic (carbon containing) materials are decomposed by heat giving rise to tarry and sooty decomposition products. The remaining H. Hence.3. the chain breaking reactions will dominate and the flame can no longer burn. that is by an extinguishing agent capable of chemical inhibition. Each of these H atoms can immediately initiate the same sequence.2. Besides. H atoms or other active species (radicals) may also be removed from the flame by purely chemical means.5. In the absence of oxygen within certain zones of the flames. IITK-GSDMA-Fire 05-V3.Handbook on Building Fire Codes temperature will be transformed in a fraction of a millisecond to form 2 molecules of H2O and 3 new H atoms.
(b) Smothering / Blanketing (or the limitation of oxygen). but it will be convenient to consider them according to the main principle involved. It has been shown from the triangle of fire that three factors are essential for combustion. ii) the presence of oxygen(usually as air) or other supporter of combustion. in principle. specific methods of fire extinction often embody more than one of these principles. consists in the limitation or elimination of one ore more of these factors. and the methods of extinguishing fire may be classified conveniently under the following headings: (a) Starvation (or the limitation of fuel). namely. FIRE EXTINCTION METHODS 3.1. or combustible substances.Handbook on Building Fire Codes SECTION-4 CHAPTER -2. STARVATION OX YG EN AT HE (B ) SMOTHERING AT HE HE OX YG EN ) (C AT COOLING OX YG EN FUEL FUEL (A) Fig-10 Fire Extinction Methods FUEL Fig-11 Triangle of Fire showing the three conventional methods of fire extinguishment-Starvation(A). In practice. and Cooling(C) IITK-GSDMA-Fire 05-V3.2 Fire extinction. i) the presence of a fuel.METHODS OF FIRE EXTINGUISHMENT 3. 3.0 Page 43 . Smothering(B). and iii) the attainment and maintenance of a certain minimum temperature. and (c) Cooling (or the limitation of temperature).
A typical example is the emulsification of the surface of burning oil.4. the drainage of fuel from burning oil tanks. usually sodium bicarbonate. Starvation 3. in so far as it is complete. from a pressurised extinguisher.4. for instance. the working out of cargo at a ship fire. when the smaller fires produced may be left to burn out or to be extinguished more easily by other means. Examples of these are. As the fusing temperature of the powder is IITK-GSDMA-Fire 05-V3. An important practical application of the smothering method is the use of foam. heath. such as uranium and plutonium.4. This forms a viscous coating over the burning material and limits. This powder (ternary eutectic chloride)is applied by means of a gas cartridge pressurised extinguisher. the demolition of buildings to create a fire stop. whilst the beating out of a heath fire owes much of its effectiveness to this. and allow the combustion to reduce the oxygen content in the confined atmosphere until it extinguishes itself. Another method of smothering is by the application of a cloud of finely divided particles of dry powder. 3. The general procedure in methods of this type is to prevent or impede the access of fresh air to the seat of the fire.4. pulling apart a burning haystack or a thatched roof.0 Page 44 .1. iii) By sub-dividing the burning material. It also tends to prevent the formation of flammable vapour.3. and forest fires.3. The extinction of fire by starvation is applied in three ways: i) By removing combustible material from the neighbourhood of the fire. the cutting of trenches in peat. 3. 3. thorium and magnesium. A further development in the smothering method has been the discovery of a powdered compound for use on metal fires.4. ii) By removing the fire from the neighbourhood of combustible material as. counter-burning in forest fires.4. Smothering 3. If the oxygen content of the atmosphere in the immediate neighbourhood of burning material can be sufficiently reduced combustion will cease.Handbook on Building Fire Codes 3.2.1. 3.3. the supply of air.
0 Page 45 .2.5. Carbon-di-oxide and nitrogen are familiar examples of this. In the interests of efficiency.5. while changing from liquid (water) to vapour state(steam) water expands about 1760 times which also contributes to its smothering effect. IITK-GSDMA-Fire 05-V3. forming as it does the basis of the application of water and other liquids to burning materials. Thus it takes about six times as much heat to convert a certain weight of water at its boiling point into steam as is required to raise the temperatures of the same amount of water from the usual atmospheric temperature to its boiling point. Cooling 3.4. The action of water depends predominantly on its thermal capacity and latent heat of vapourisation.5.Handbook on Building Fire Codes in the region of 580oC it forms a crust over the burning metal and this excludes the oxygen of the air. Another example is the emulsificaton of the surface of oil by means of the emulsifying type of spray nozzle producing an oil-in-water-emulsion.5. combustion cannot persist. The smothering effects of the steam produced at the seat of the fire is thought to play a part in assisting in the extinguishig process. The vigorous discharge of an inert gas in the immediate vicinity of the fire may so reduce the oxygen content of the atmosphere for the time being that combustion cannot be maintained. A group of extinguishants consisting of volatile liquids based on the halogenated hydrocarbons are also in use. If the rate at which heat is generated by combustion is less than the rate at which it is dissipated through various agencies.5. 3. These evaporating liquids act partly as inerting blankets similar to those mentioned in the preceding section. 3. 3. In fact.5.1. 3. the latter being by far the more important. 3.3. it is clearly desirable that water should be applied to a fire in the liquid condition and in such a way that as much as possible is converted to steam. The cooling principle in fire extinction is the one most commonly employed.4. The application of a jet or spray of water to a fire is invariably based on this simple but fundamental principle. There are many variations. and partly by chemical interference with the chain reaction of flame propagation.
2 kJ/kg/oC and latent heat of vapourisation is 2260 kJ/kg This fact.5. each of its four sides representing one of the four basic requirements: fuel. Fig. Fire scientists have now found that there is a fourth constituent in all flaming fires which plays a vital part in the fire growth and sustenance.2. This last factor comes into play only in flaming mode of combustion which is normally applicable in the case of flammable liquids and gases. This is the unbroken or uninhibited chain reaction. the previous figure of triangle of fire has been transformed into a tetrahedron of fire. (Ref. active free radicals of OH*. combined with its availability in large quantities. temperature. 4. the flame becomes inhibited and extinguishment is achieved.1. water is an excellent fire extinguishing agent since both figures are high.0 Page 46 . On application of these agents. The extinguishing agents used for this purpose are halogenated hydrocarbons or halons/halon alternatives and several types of dry chemical powders. H* and O* species are produced which act as 'chain carriers' which help to sustain the flame. Thus. the thermal capacity or specific heat of water is 4.5. as per modern concept.10) Extinguishment of fire by flame inhibition or breaking the chain reaction is achieved when these active free radicals or chain carriers are inhibited or eliminated. due to chemical reaction. IITK-GSDMA-Fire 05-V3. makes it by far the most useful fire extinguishing agent for general purposes. In the flame front. On the basis of thermal capacity and latent heat of vapourisation. The triangle of fire representing three basic constituents of fire is the conventional concept. Fig-12 Tetrahedron of Fire 4. For instance. Tetrahedron of Fire (Fourth factor contributing to fire) 4. oxygen and unbroken or uninhibited chain reaction.Handbook on Building Fire Codes 3. This principle of fire extinguishment is known as 'breaking the chain reaction" which is achieved by removal/ suppression of the free radicals.
0 Page 47 .Handbook on Building Fire Codes STARVATION FUEL COOLING HEAT FIRE OXYGEN SMOTHERING UNBROKEN CHAIN REACTION INHIBITION / BREAKING CHAIN REACTION (BY REMOVAL / SUPPRESSION OF FREE RADICALS) Fig-13 Fire Extinguishment(Fourth Factor) IITK-GSDMA-Fire 05-V3.
limestone and dry sand are normally suitable for class 'D' fires. etc. and ii) Those that are immiscible with water. butane.0 Page 48 .Handbook on Building Fire Codes SECTION-4 CHAPTER -3. For the purpose of choosing effective extinguishing agents. Class 'A' fires are the most common. propane. Special fusing powders have been developed for fires involving some metals. or a liquid or gas leak. in which combustion generally occurs with the formation of glowing embers. (water in the form of spray is generally used to cool the containers. powdered talc. especially the radioactive ones. Powdered graphite. soda ash. Class 'A' These are fires involving solid materials normally of an organic nature (compounds of carbon). foam. vapourising liquids. and these include methane.EXTINGUISHING MEDIA 5.1 Internationally accepted classification of fires is as follows. carbon dioxide and chemical powders. Class 'B' These are fires involving liquids or liquefiable solids. the extinguishing agents include water spray. Classification of fires 5. flammable liquids may be divided into two groups: i) Those that are miscible with water. Foam or dry chemical powder can be used to control fires involving shallow liquid spills. Extinguishing agents containing water are ineffective. Depending on (i) and (ii). Presently special dry chemical powders have been developed for extinguishing metal fires. and even dangerous. Class 'C' These are fires involving gases or liquified gases in the form of a liquid spillage. IITK-GSDMA-Fire 05-V3. Effective extinguishing agent is generally water in the form of a jet or spray.) Class 'D' These are fires involving metals. Carbon dioxide and the bicarbonate classes of dry chemical powders may also be hazardous if applied to most metal fires.
The method of applying water to a fire varies according to the size of the fire. 6.1. Some of the special properties which make water as the most efficient and generally accepted extinguishing agent are: Water has a high sepecific heat capacity are 4. must. A variation in the application of water can be made by means of nozzles that produce jets or sprays ranging from large sized droplets down to atomised fog effects. 6. 6.1.2. atleast 4 times higher than that of any other non flammable liquid It is outstandingly non-toxic Its B. The normal procedure in such circumstances is to cut off the electricity and use any extinguishing method appropriate to what is burning. according to present-day ideas. in fact. that electrical fires constitute a separate class. be a fire of class A. These include vapourising liquids. B or D. or started by. EXTINGUISHING AGENTS / MEDIA 6.3. Judicious use of this type of application can not only cut down the amount of water used. water is still the most efficient.1. and the built-in pumps driven by the vehicles' engines are often capable of pumping 4500 litres (1000 gallons) per minute (or more) giving the necessary energy to the water to provide adequate striking power. (100oC) is well below the 250o C to 450oC range of pyrolysis temperatures for most solid combustibles IITK-GSDMA-Fire 05-V3. For major fires. and other gaseous extinguishing agents.1.2 Electrical fires It is not considered. but will ensure that it is used to greater effect. cheapest and most readily available medium for extinguishing fires of a general nature.1. 6. electrical equipment. since any fire involving. minimising water damage. dry powders carbon-di-oxide.4.2 kJ / kg / per oC Water has a high latent heat heat of evaporation per unit mass. Only when this cannot be done with certainty will special extinguishing agents be required which are non-damaging to equipment.P.1 WATER 6.0 Page 49 .Handbook on Building Fire Codes 5. Despite the many new techniques which have come to the assistance of firemen. greater quantities of water are necessary.
3.5.2. although in most cases it would be rather less than this. it was usual to allow 50 litres per square metre (1 gallon of foam per square foot) of surface area per minute as the ideal rate. The desirable characteristics of foam are resistance to radiant heat.1. 6.Handbook on Building Fire Codes Water extinguishes a fire by a combination of mechanismscooling the combustible substance. generating steam that prevents oxygen access. to fuel vapours and to loss of water content by drainage. In practical fire fighting water has to be applied at 10 to 100 times the rates prescribed in laboratory tests because of the difficulty of ensuring that the bulk of it reaches the burning surfaces.5. Classification Foam concentrates can be classified in two ways:(i) Classification by Expansion Low expansion Medium expansion High expansion (LX) (MX) (HX) Expansion Ratio Low expansion up to 50:1 (Usually between 5:1 and 15:1) Medium Expansion: Between 50:1 and 500:1 (Usually between 75:1 and 150:1) High Expansion: Between 500:1 and 1000:1 (Usually between 750:1 and 1000:1) IITK-GSDMA-Fire 05-V3. without being too sloppy. cooling the flame itself. As per conventional standards.2. It should flow readily and recover a surface if disturbed. FOAM AND FOAM-MAKING COMPOUNDS 6. 184.108.40.206. Foam as used by fire brigades is usually generated by the mechanical agitation of a diluted foam compound solution in the presence of air. and 3.5. Note: Additional information on the special properties which inquality water as an excellent extinguishing agent have already been given in para 3.2.5. and as fog blocking the radiative transfer of heat.2. 6.0 Page 50 . 6. The most satisfactory measure of the efficiency of the foam as a firefighting agent is the minimum rate of application at which a fire is controlled by the agent.
Fluroprotein Foam Concentrate Generally used at 4% concentration for low expansion foam production having an expansion ratio of about 9:1. Makes a stiff foam with good resistance to burnback. Undiluted concentrate may strip paint. Good resistance to burnback and resistant to fuel contamination. like acetone. Expansion Ratio about 8:1.5% to 2% for high expansion foam. Alcohol Resistant Foam Concentrate Usually protein foams with additives used at 4% to 6% concentration for low expansion foam. 75 to 150:1.0 Page 51 . Undiluted concentrate may strip paint and care should be taken not to allow contact with the skin.Handbook on Building Fire Codes (ii) Classification by Constituents Protein Foam Concentrate Generally used at 4% concentration for low expansion foam production. Particularly effective on low boiling point hydrocarbon fuels. and it is susceptible to fuel/foam mixing and breakdown by radiant heat and hot fuel. and 1. More fluid than protein foam giving quicker control and extinction of fires. Very fluid foam. Has the ability to resist water miscible liquids. making it the most suitable type for sub-surface injection for oil tanks. since it provides a film over the liquid surface which prevents vapour formation. Synthetic Foam Concentrate Generally used at 2% to 3% concentration for low and medium expansion foams. Effective on hydrocarbon fuels and some water miscible liquids. but burnback resistance not as good as the protein and fluoroprotein types. and care should be taken not to allow contact with the skin. Fluro-Chemical Foam Concentrate Generally used at 3% to 6% concentration for low expansion foam production having an expansion ratio of about 10:1. IITK-GSDMA-Fire 05-V3. but burnback resistance is not good.Forming Foam' (AFFF). Commonly known as 'Aqueous Film . and 750 to 1000:1 respectively). (Expansion Ratios 11:1. gives rapid control and extinction of fire. Gentle surface application will give quick control and extinction. Effective on most hydrocarbon fuels but not on water miscible liquids. and is the only practical choice for fires in many polar solvents.
5. but there may be a slight detrimental effect on the performance of any one type.0 Page 52 . 6. A hose to deliver water to the required point. Fireground Formula (i) Number of foam making branches / generators required at incidents for a circular tank 4D2 Output of branch in litres per minute i. A means of introducing the foam concentrate into the water stream. Do not mix different batches of the same brand and type of foam concentrate. Do not mix different brands of the same type of foam concentrate. A means of aerating the foam concentrate/water mixture. Branches available FB5x (output . Foam Making Equipment The basic items of equipment required to produce foam are as folows: A pump to impart the necessary energy to the water.e. (ii) Follow manufacturer's recommendations with regard to the combined use of dry powders with foam.6. Some interact severely. but as a broad basic guide. 6.Handbook on Building Fire Codes 6.2.2. Aerating and projecting are often carried out by the same piece of equipment.4. the following points should be borne in mind: Do not mix different types of foam concentrates in the same equipment.A means to project the foam on to the fire. Compatibility of Foam Concentrates and Foams (i) It is important in all cases that the manufacturer's instructions should be adhered to.2.225 lpm foam solution) IITK-GSDMA-Fire 05-V3. Different foams may be used together on the same fire.
) 0-14 5. 10FB No.2.9 Pressure Finished Foam (bars) (Litres/min) 5-7 7 7 7 7 2000-2300 2050 3640 7270 10900 FB5x No.7. 6.2.Chemical Synthetic Alcohol Resistant Overall Average Weight per 100 litres 108 kg 118 kg 102 kg 110 kg 115 kg 111 kg = 4x100 225 = 2 6. (Litres/min. 30FB IITK-GSDMA-Fire 05-V3.Handbook on Building Fire Codes Eg: For a tank of diameter 10m: No.Foam Making Branches (Low Expansion) Type Water (Litres/min) 200-300 225 455 909 1360 Foam Conc.metres) plus reserve 50 for topping up due to natural breakdown and wastage. 20FB No.3 40.7-8 13.6 27. Therefore.8. of FB5x required = 4D2 225 (ii) High expansion foam concentrate required: 1 litre produces approximately 50 ou metres of high expansion foam. Cubic capacity (in cu. approx. 2FB No. Weight of Foam Concentrates Type Protein Fluoro Protein Fluoro . Output .0 Page 53 .
Halogenated extinguishing agents. where fire hazards are high. 3 H A L O G E N AT E D A G E N T S ( H A L O N S A N D H A L O N ALTERNATIVES) 6. required 1600lit 16000 lt (20 tonnes) 160000 lt (200 tonnes) 10000 m2 8000 lpm 20 mins.Handbook on Building Fire Codes 6. though a relatively recent innovation in fire protection.1. (c) In Industrial and Storage Occupancies handling. and the types of foam generator and branchpipes vary considerably with the size of fire. As per guidance. Note: A major fire outbreak in a big oil installation may last for several hours. They have been phased out already in the developed countries from 1st Jan. in addition to trained man power and several fire appliances will be required. large quantities of water and foam compounds. IITK-GSDMA-Fire 05-V3. are already being phased out. Being a highly complex and specialised operation. and will be phased out in the developing countries like India by 2010. lot of pre-planning will be necessary.3. the following figures will be useful: Area of Fire Rate of Application of foam concentrate 100m2 1000 m2 80 lpm 800 lpm For duration 20mins. for tackling major fire outbreaks. 1994. since they have very high Ozone Depletion Potential or ODP (power for depleting the ozone layer above the earth which acts as a shield for protecting mankind from the harmful ultra-violet rays from the sun).2. 6 . or sometimes even for days. (b)The foam concentrate requirements for dealing with large area flammable liquid fires will be considerable.0 Page 54 . 20 mins.6. Hydrocarbon Fires (Amounts of Foam Required) (a) The amounts of foam concentrate and foam solution. processing and storage of large quantities of flammable liquids. Foam Conc.
Handbook on Building Fire Codes 6.3. In so far as India is concerned. Fire Protection-Fire Extinguising Media. in which some or all the H atoms are replaced with Flourine(F).3. HFC-227 ea (FM-200) Total Flooding System. The Halons are chemical derivatives of Methane (CH4) or Ethane (C2H6). Most of the fires could be extinguished with 4 to 6 percent by volume of H1301. since it has the lowest toxicity and highest extinguishing efficiency. Inert Gaseous Total Fire Protection(Total flooding) Systems--Inergen.3. NAF S-III(HCFC Blend A) Total Flooding System. Installation and Commissioning.4. CF3Br) is the most commonly used. during the last decade several Halon alternatives have been developed in the world market. Nitrogen. Because of the phasing out of the Halons.2. Gaseous Fire Extinguishing System--Regular Maintenance. (ix) (x) (xi) (xii) Specification for Halon 1211 and Halon 1301 for essential use(ISO 7201-1:1989) Code of Practice for Safe Handling and Transfer Procedures of Halon 1301 and 1211. They are: (i) (ii) (iii) (iv) (v) (vi) (vii) Gaseous Fire Extinguishing Systems--General Requirements for design. Water Mist Fire Protection Systems. IITK-GSDMA-Fire 05-V3. 12 new Indian Standards on Halon Alternatives are in the process of publication by the Bureau of Indian Standards. Carbondioxide systems. Carbon-dioxide-Quality Assurance Test For Fire Extinguishing CO2 Gas. including high and low pressure and incabinet sub floor system. 6. Of the various Halons. Argonite. Argon.0 Page 55 . Chlorine(Cl) or Bromine(Br) atoms. (viii) Methods for Tests for determining fire extinguishing and inerting concentrations for flammable liquids and gases. Halon 1301(Bromo-trifluoro-methane. or by combinations of these halogen elements. Specification for Powdered Aerosol System.3. 6.
NFPA published NFPA-2001.3. which is the Standard on Clean Agent Fire Extinguishing Systems.5. National Standards on Halon Alternatives have already been published. International Scenario: (i) In developed countries like USA.0 Page 56 .Handbook on Building Fire Codes 6. The relevant Table showing the agents addressed in 2000 Edition of NFPA-2001 is reproduced below: 4 IITK-GSDMA-Fire 05-V3.
testing and training. maintenance. inspection.0 Page 57 . components and system design. IITK-GSDMA-Fire 05-V3. hazards to personnel. guidance and implementation. marine systems. The Gaseous Fire Extinguishing Systems for which ISO has published Standards are listed below: (See next page) (iii) Halons Technical Options Committee(HTOC) under the United Nations Environment Programme (UNEP) is the nodal International Body dealing with all subjects connected with Halon Phase-out and Halon Alternatives. (ii) Similar new Standards have been published by British Standards Institute and Standards Australia and few other countries. besides International Standards Organisation (ISO). safety. use and limitations.Handbook on Building Fire Codes The NFPA-2001 covers all aspects of the HAs like applicability. This expert body issues exhaustive guidelines on these subjects which are meant for global application. tests etc.
0 Table .5 .Handbook on Building Fire Codes IITK-GSDMA-Fire 05-V3.Listed extinguishants (ISO) Page 58 .
which acts as the primary fire suppression factor) (ii) The fine droplets evaporate in the hot environment even before reaching the flame. (d) There are currently two basic types of water mist suppression systems: single and dual fluid systems. and (iii) In portable extinguishers. The three methods of application of Water Mist are: (i) Fixed installation . Water Mist . (c) Analytical studies have indicated that water liquid volume concentrations of the order of 0.3. In addition to clean total flooding gaseous Halon Alternatives.6. This represents a potential of two times effectiveness in extinguishment over application rates for conventional sprinklers. Single fluid systems utilise water stored at 40-200 bar pressure and spray nozzles which deliver droplets of size 10-100 microns diameter range.(a) This is a comparatively recent development as a Halon Alternative. of water per m3 of air is sufficient to extinguish fires in the gas phase.7. new technologies such as Water Mist and Fine Solid Particulates are being introduced. (b) Water Mist extinguishes a flame by adopting the following mechanisms: (i) Mist droplets evaporate removing heat and producing cooling (gas phase cooling.Handbook on Building Fire Codes 6.0 Page 59 . Fine Water Mist technology relies on relatively small (less than 200 microns) droplet sprays to extinguish fires. generating steam and effecting smothering (oxygen depletion) (iii) The mist blocks radiative heat transfer between the fire and the combustible.in a compartment / room for total flooding (ii) Fixed spray nozzles. for local application. 6.3.1lit. IITK-GSDMA-Fire 05-V3.
CARBON-DI-OXIDE 6. 6. Both types are promising fire suppression systems. IITK-GSDMA-Fire 05-V3. (b) Extinguishment is achieved by combined action of two factors such as flame cooling due to aerosol particles heating and vaporising in the flame front as well as a chemical action on the radical level. where it is contained under a pressure of approximately 51 bars (750 1bf/in) at about 15oC. extinguishes by smothering.8. or reducing the oxygen content of the air. It is non combustible. Solid aerosols must act directly upon the flame.4.5 times as dense as air.2.Handbook on Building Fire Codes Dual systems use air.3. It will not conduct electricity and can be used on energised electrical equipment. These take advantage of the well established fire suppression capability of solid particulates. carbon-di-oxide is a gas.1. As the fire extinguisher is discharged. does not react with most substances and provides its own pressure for discharge from the storage container. Being a gas. Nitrogen or other gas to atomise water at the nozzle. toxicity problems about this new technology pose potential concerns. Fine Solid Particulate Technology (a) This technology has also been developed recently relating to fine solid particulates and aerosols. Gases serve as a mechanism for delivering aerosol towards the seat of a fire. it can easily penetrate and spread to all parts (including hidden) of the fire area. extracting heat from the surrounding atmosphere. (c) However.4. the liquid boils off rapidly as a gas.0 Page 60 . Carbon-di-oxide posseses a number of properties which make it a good fire extinguishing agent. (e) Water mist system using pure water do not present a toxicological and physiological hazard and are safe for use in occupied areas. The gas. At normal temperatures.4. It is easily liquified and bottled. Also it leaves no residue. 6. One principle of these aerosol extinguishants is in generating solid aerosol particles and inert gases in the concentration required and distributing them uniformly in the protected space. however. Aerosol and inert gases are formed through a burning reaction of the pyrotechnic charge having specially proportioned composition. 6. Also there are no concerns regarding ozone depletion or global warming or atmospheric lifetime potentials. 1.
Minimum CO2 Concentration required for extinguishment of various materials Materials Acetylene Acetone Benzol. a concentration of 9% in air is the maximum most persons can withstand without losing consciousness within a few minutes 6. The extinguising concentration of CO2 required for various types of fuels vary from approx.4.3. Benzene Butadiene Butane Carbon Disulfide Carbon Monoxide Coal Gas or Natural gas Cyclopropane Dowtherm Ethane Ethyl Ether Ethyl Alcohol Ethylene Ethylene Dichloride Ethylene Oxide Gasoline Hexane Hydrogen Isobutane Kerosene Methane Methyl Alcohol Pentane Propane Propylene Quench. Table 6 . As regards toxicity. 30% to 62% depending upon the fuel.4. Lubricating Oils Minimum Extinguising Concentration required 55 26* 31 34 28 55 53 31* 31 38* 33 38* 36 41 21 44 28 29 62 30* 28 25 26 29 30 30 26 Note: Apart from the above the safety factor concentration has also to be added IITK-GSDMA-Fire 05-V3.4.0 Page 61 .Handbook on Building Fire Codes 6.
Now extinguishing systems based on steam are rarely used. 6. respectively.Handbook on Building Fire Codes 6. CO2 is substantially more effective than N. or CS2 which would require greater dilution. These systems use pressure reducing devices at or near the discharge manifold.4.5. and one blend contains CO2 (approx. A by-pass is opened first to warn occupants. Table 7 on the next page denotes the physical properties of the inert gas agents. A reduction of the O2% in the air from 21% to 10% by volume would make fires and explosions impossible. These systems are not effective for total flooding. both have nearly equal effectiveness as CO2 is 184.108.40.206 times heavier than N 6.1. oil quenching tanks etc. The control valves are opened slowly.6. There have been at least four inert gases or gas mixtures developed as clean total flooding fire suppression agents. They are not liquefied gases. On a volume basis. INERT GASES 6.6. except for a few special gases like H. Hence they require high pressure storage cylinders. 8%).4. C2H2. Discharge times are of the order of one or two minutes. but are stored as high pressure gases. Inert gases are used in design concentrations of 35 to 50 % by volume which reduces the ambient oxygen concentration to between 14% to 10% by volume.0 Page 62 . It is actually the depletion of the O2 level in the air which is responsible for extinguishment in the case of inert gases.5. but only for local application by hand held branches or lances. refineries.6. Steam is taken from boilers through fixed piping.1. Manual systems with flexible tubing and lances are more common. It is known that for most typical fuels oxygen concentrations below 12 to 14% will not support flaming combustion. IITK-GSDMA-Fire 05-V3. However. STEAM 6. These systems may still be seen in some of the benzol plants. Only in certain ship's holds and occasionally in industries involving flammable liquids they are used.2. on weight basis. The inert gas mixtures developed so far contain Nitrogen and / or Argon. 6. Steam is the oldest among the smothering agents. 6.
Kg/m3 Heptane Extinguishing Conc. VOL % Minimum Class B fire design Conc.7 Table -7 .4 1.661 37.3 1. VOL% (i) Handbook on Building Fire Codes Inerting:Methane-Air.8 47.9 35. stored gas Gas Density @ 20oC.0 IG-541 Inergen 52% 40% 8% Inert gas blend Inert gas blend 0% 50% 50% 0% 100% 0% I e tg s nr a Argonite Argotec IG-55 IG-01 IG-100 NN 100 100% 0% 0% I e tg s nr a Compressed gas Compressed gas Compressed gas Compressed 1.8 31.6 1.1 34.412 32.3 36.434 29.0 41..3 41.VOL% Page 63 . design concentration.9 61.6 40.9 33. VOL % (1) Minimum Class A fiire desing Conc.5 45.Physical Properties of Inert Gas Agents Generic Name Trade Name Chemical composition Nitrogen Argon Carbon-di-oxide Chemical Group Agent form.165' 33.IITK-GSDMA-Fire 05-V3..
7. Dry chemical is expelled from containers by gas pressure and. but also for general application in large quantities.7. and enables a relatively close attack to be made. and so new methods of extinction have been evolved. 29% and 51% respectively for the three chlorides) . not only in portable extinguishers. effectively sealing it from the surrounding atmosphere and isolating the fire. and to reduce packing in the cylinder. Special powders have been developed for some metal fires. This.3. Dry chemical powder can also be supplied in polythene bags for metal fires.7. with the addition of a metallic stearate as a waterproofing agent. other additives like silicones are also used to decrease the bulk density. by means of specially designed nozzles. is widely used as an extinguishant. Dry chemical powders are also tested for their compatibility with foam. 6.5. The base chemical of most dry chemical powders is sodium bicarbonate. On most fires involving burning metals. This cloud also screens the operator from the flames. IITK-GSDMA-Fire 05-V3. then flows a little and forms a crust over the burning metal. Apart from stearates. These powders contain an ingredient which melts.7. These powders which are 10 to 75 microns in size are projected on the fire by an inert gas (usually CO2 or N).Handbook on Building Fire Codes 6. 6. 6.7. (Chlorides of Sodium) (Na). and is directed at the fire in a concentrated cloud. as it is more effective to bury the fire under a pile of bags which melt and allow the contents to smother the fire. and the two should complement each other on fires where foam is the standard extinguishant.7. DRY CHEMICAL POWDERS 6. These are known as the 'ternary eutectic chloride' group. 6.0 Page 64 . as it was discovered that the early powders tended to break down foam. especially for the radioactive metals such as uranium and plutonium. Potassium(K) and Barium(Ba) (in the proportions of 20%.1.4.2. the result of applying water can be explosively disastrous.
Carbamate) Formula NaHCO3 NaCl KHCO3 KCl K2SO4 (NH4) H2PO4 NH2CONH2 + KHCO3 Other Name(s) Baking soda Common salt "Purple K" "Super K" "ABC" or Multipurpose Powder "Monnex" 6. They also absorb heat by blocking radiative heat transfer.Handbook on Building Fire Codes The commonly used dry chemical agents are listed below: Chemical Name Sodium bicarbonate Sodium chloride Potassium bicarbonate Potassium chloride Potassium sulffide Monoammonium phosphate Urea + potassium bicarbonate (Pot.7. Any dry chemical powder can cause some degree of corrosion or other damage. These dry chemicals.2.7.9. and that is mono-ammonium phosphate (MAP).8. IITK-GSDMA-Fire 05-V3. Only one among the above is effective against deep-seated fires because of a glassy phosphoric acid coating that forms over the combustible surface on application. by forming a surface coating. 'Monnex' drychemical is approx. of Chapter 1. being acidic. Potassium bi-carbonate based agent.6. can damage delicate electrical / electronic equipment. often known by the name 'Purple K' is approx. 6. twice as effective. like breaking of chain reaction as explained in para 2. Section-4 presumably forming volatile species that react with H atoms or hydroxyl radicals. 3 times as effective as the conventional soda bi-carb. The powders act on a flame by some chemical mechanism.7. corrodes more readily than other dry chemicals which are neutral or slightly alkaline.7. 6.7. and in the case of MAP. based dry chemical. but MAP.0 Page 65 . as conventional soda bi-carb. on unit weight basis. especially MAP.2. based dry chemical. 6.
First Aid Fire Fighting Equipment covers mainly portable fire fighting equipment like Fire Extinguishers.1 The previous 3 chapters under this Section had dealt with: The constituents of fire (What is fire?) The methods / principles of fire extinguishment (How fire can be put out) Extinguishing Media (the extinguishing agents used for putting out a fire) 7. and the third. test. knowledge of the main principles involved in their installation. although it is. General 7. all of which come under the active fire protection sector: (a) Fire Detection and Alarm Systems (Automatic Fire Alarm Systems). Fire Detection and Alarm Systems and Fixed Fire Extinguishing Systems. (a) The first two. (b) Automatic fixed extinguishing systems have proved to be the most effective means of controlling fires in buildings. an essential requirement for ensuring fail-free operation of all types of fire protection systems is that all persons who may be expected to inspect.Handbook on Building Fire Codes SECTION-4 CHAPTER -4.2. (c) Apart from the sound design and installation of the systems. (b) Fixed Fire Extinguishing Systems / Installations and (c) First Aid Fire Fighting Equipment. This Chapter deals with the undermentioned important component items of fire protection requirement of a building or structure or facility. a type of fixed installation. 7. uses and applications are necessary. For understanding the capabilities of these systems. which are normally included under First Aid Fire Fighting Equipment.3. in fact.0 Page 66 . maintain or operate fire extinguishing systems shall be thoroughly trained and kept thoroughly trained in the IITK-GSDMA-Fire 05-V3. are both fixed installations.FIRE SUPPRESSION EQUIPMENT & INSTALLATIONS (ACTIVE FIRE PROTECTION MEASURES) 7. except Hose Reels.
Among the fire protection requirements for a building. For eg. Detectors are designed to detect one or more characteristics of fire (also known by the term "fire signatures". viz. IITK-GSDMA-Fire 05-V3. If properly designed. and the choice will depend on the type of risk to be protected. No one type of detector can be considered as the most suitable for all applications. and is worthy of adoption by our Codes also).. But.18.104.22.168. and secondarily for the protection of property.1. Some materials burn intensely giving out high levels of thermal energy. Different types of fires can have widely different fire characteristics (fire signatures). General 7.1. but with little or no smoke. response time and extinguishment time.4. proper selection and siting of fire detectors are essential for achieving the fire protection objectives.4. (aerosol particles) and flame (radiant energy-IR. (This requirement is invariably emphasised in all NFPA Standards.0 Page 67 .3. whereas smouldering fires have no visible flame and usually have low heat output. the reaction time. it will be good if the designers and builders keep themselves aware of the fact that recent fire research and analytical studies have come to the conclusion that partial detection does not often.4. visible.1. Building Codes may stipulate. provide early warning of a fire condition. FIRE DETECTION AND ALARM SYSTEMS (AUTOMATIC FIRE ALARM SYSTEMS) 7. if ever. 7. UV). sometimes. installed and maintained. the alerting time. This objective can be achieved to any satisfactory level only if the building has been provided with a well designed and reliable automatic fire alarm system. evacuation time.1. partial coverage by detection systems. to the utmost possible extent. automatic fire alarm systems can be a substantial help in minimising losses of lives and property from fires in buildings of all types of occupancies. Under the circumstances. 7.. heat. Automatic fire alarm systems are used primarily for the protection of lives.2. One of the prime objectives of good fire protection in a building is to reduce.. smoke.4. the time delays which follow a serious fire outbreak. as per NFPA). fire detection and alarm system has an important role to fulfil.Handbook on Building Fire Codes functions they are expected to perform. viz. 7.4. 7.
The methods used to detect heat are given below: (a) By fusible metals or metal alloys.1. which have a linear sensing device usually protecting a larger area. designed to operate when the temperature rises abnormally quickly.0 Page 68 . Heat Detectors 7. or when a pre-determined temperature is reached. which are small.2. These can again be subdivided into two types: (i) Point detectors. or (ii) Line detectors. Note: The temperature range normally adopted for heat sensitive (point) detectors is from 55oC to 180oC. 7.4. (b) Rate-of-rise detectors. and which in turn activates the fire alarm. which operates an electrical circuit.4.2. which melt when a pre-determined temperature is reached. There are two types of heat detectors: (a) Fixed temperature detectors.Handbook on Building Fire Codes 7.2. A figure depicting this principle is given below: Fig-14 Fusible Link Detector IITK-GSDMA-Fire 05-V3. each protecting a limited area. inclusive if the rate of rise of the temperature is less than 1oC/min. which are designed to operate when the detecting mechanism or element reaches a pre-determined temperature.2.4.
Handbook on Building Fire Codes (b) Heat sensitive covering in cable assembly(thermostatic cables) In this. Figures depicting these principles are given below: Fig-15 Heat detector using expansion of metal strip principle IITK-GSDMA-Fire 05-V3.0 Page 69 . two conductors are insulated from each other by a heat sensitive covering. (c) Expansion of metals The movements created by expanding metals or bi-metal strips are used to make or break electrical circuits. At the rated temperature the covering melts and the two conductors come into contact initiating an alarm.
Bi-metal strip type Fig-17 Heat detector .Rate-of-rise principle IITK-GSDMA-Fire 05-V3.Handbook on Building Fire Codes Fig-16 Heat detector .0 Page 70 .
Using principle of expansion of air (pneumatic detector) 7.Handbook on Building Fire Codes (d) Expansion of Gases(pneumatic detector) This consists of an air chamber having a flexible diaphragm which can move an electrical contact.4.0 Page 71 . Heat causes the air pressure in the chamber to increase. Smoke Detectors.3. There are two types: 7. making the diaphragm flexed to close the electrical contact.4. A figure of this follows: Fig-18 Heat detector .1. Ionisation Detector Figures depicting Ionisation type of smoke detector under 'non-fire condition' as well as 'fire condition' are shown overleaf: IITK-GSDMA-Fire 05-V3.3.
0 Page 72 .Non-fire condition Fig-19 (b) Ionisation Detector -fire condition IITK-GSDMA-Fire 05-V3.Handbook on Building Fire Codes Fig-19 (a) Ionisation Detector .
2. When smoke particles enter a chamber. An optical detector has two important components.4. in a fire situation. Others are designed so that less light is thrown onto the photo-electric cell in a fire situation.Handbook on Building Fire Codes The basic principles involved in Ionisation detector are as follows: The detector head consists of one (or two) Ionisation chamber(s) connected to form a balanced electrical circuit. and a radio active source (usually an alpha-particle source . The Ionisation chamber contains two electrodes.usually Americium 236) ionises the air producing positive and negative ions which get attracted to the electrodes of opposite polarity. This results in a reduction in the current flow in the chamber which actuates an alarm. small particles of smoke. The figures of these two types are shown below: Fig-20 (a) Optical Detector . reacts to the visible products of combustion. the charged ions attach themselves to some of the particles thereby slowing the movement or flow to the electrodes. Optical Detector While the ionisation detector responds to the invisible products of combustion. This flow of ions creates a current flow across the electrodes. across which a potential difference is maintained. a light source and a photo-electric cell. including.3. These are called the obscuration type. as its name implies. Some optical detectors are designed so that. These are called the light scatter type. the optical detector.0 Page 73 . The critical factor in the operation of this type of detector is the amount of light falling on the photo-electric cell.Light scatter type(Non fire condition) IITK-GSDMA-Fire 05-V3. 7. more light is thrown onto the photo-electric cell.
Obscuration Type-fire condition IITK-GSDMA-Fire 05-V3.Light scatter type(fire condition) Fig-21 (a) Optical Detector .Handbook on Building Fire Codes Fig-20 (b) Optical Detector .0 Page 74 .Obscuration Type-Non-fire condition Fig-21 (b) Optical Detector .
2.4. and (iii) Ultra-violet radiation (see figure 22 below).4. Infra-red Detector (a) The figure given overleaf illustrates the basic components of this detector: IITK-GSDMA-Fire 05-V3. fire releases radiant energy in the form of : (i) Infra-red radiation.4.4. These detectors are designed to respond specifically to(i) Infra-red radiation.Handbook on Building Fire Codes 7. or (ii) Ultra-violet radiation. Flame Detectors 7.1. Apart from producing hot 'gases'. Fig-22 Forms of radiant energy produced in a fire These forms of energy travel in waves radiating from the point of origin. and radiation detectors (flame detectors) are designed to respond to this radiation. (ii) Visible light.4. or (iii)Combination of IR/UV radiation 7.0 Page 75 .4.
The flame has a distinctive flicker. The detector has a neon flasher to indicate which head has been activated. false alarms are avoided or minimised. Thus.0 Page 76 . Fig-24 A typical Infra-red Detector IITK-GSDMA-Fire 05-V3.50Hz. The filter / amplifier will amplify signals in this range as well as filter out signals which are not in this range. The signals in this range are then fed to the integrator / timer which will activate the alarm circuit only if the signal persists for a pre-set period of normally 2-15 secs. normally in the frequency range of 5Hz . The figure of a typical Infra-red radiation detector unit is given below.Handbook on Building Fire Codes Fig-23 Components of an Infra-red Detector b) The lens and filter will allow only Infra-red radiation to fall on the photo electric cell. On getting the radiation. the cell will transmit a signal to the filter / amplifier.
The conventional Infra-red detector is designed to protect small areas. even upto a radius of approx. infra-scan radiation detectors are provided. and hence UV detectors do not normally respond to sunlight. The figure of a typical infra-scan detector is given below: - Fig-25 A typical Infra-scan Detector 7.4. Solar radiation in this range is absorbed by the high altitude ozone layer. period. The components of an ultra-violet detector are shown in the figure overleaf: IITK-GSDMA-Fire 05-V3. and then raises the alarm. and a wide angle on the vertical plane. The moment the photo-electric cell is struck by deflected infra-red radiation. the detector monitors 360 degrees in the horizontal plane. In this.3. to 270 nm. This detector is able to provide protection for a large area. the filter amplifier identifies it and the integrator stops the deflector so that the radiation falls continuously on the photo-electric cell. The timer checks whether the flame flicker persists for more than the 2-15 secs. Ultra-violet detector This detector responds only to ultra-violet radiation emitted from flames.0 Page 77 . and normally operates in the range of wavelengths from 200 nm.4.Handbook on Building Fire Codes (c) Infra-scan radiation detector . For larger areas with a more open plan. 90m.
These detectors are also under use and they are designed as point type resettable multisensor fire detectors installed in buildings. warehouses. and the alarm is raised when there is a change in the current flow. paint spray booths etc. Multi-sensor fire detectors .5. 7. oil rigs.Handbook on Building Fire Codes Fig-26 Components of an Ultra-violet Detector The principle of operation of this detector is very similar to that of the ionisation detector.4.4. The integrator helps reduce false alarms caused by external sources of ultra-violet radiation like lightning or even sunlight. This type of detector is commonly used for specialised applications. General Automatic fire detection system should have detectors suited to the risks and the environmental conditions so that they provide the IITK-GSDMA-Fire 05-V3. When ultra-violet radiation strikes the gas filled tube it ionises the gas in the tube. Choice / Selection of Fire Detectors 7. A small current is set up between the two electrodes.4. fuel storage tanks. and in which the signal(s) of the smoke sensor(s) is combined with the signal(s) of the heat sensor(s) 7.4.1. incorporating atleast one smoke sensor and another sensor which responds to heat. as for aircraft engine nacelles.0 Page 78 . In a smoky fire infra-red detectors are preferable to ultra-violet types because the former can penetrate smoke better.4.5.
This information will help in the choice of detectors for providing protection for various kinds of fire situations as indicated against them: In general.Handbook on Building Fire Codes earliest reliable warning. Optical beam smoke detectors incorporating thermal turbulance detectors are particularly suitable for clean burning fires. but are less sensitive to the smaller particles found in clean burning fires. Smoke detectors cannot detect products from clean burning liquids such as alcohol. ensure operation of detectors on escape routes before optical density exceeds 0. Ionisation smoke detectors are unsuitable for smouldering / PVC / polyurethane foam / clearly burning fires like Hydrogen.0 Page 79 . particles found in optically dense smoke. Each type of detector responds at a different rate to different kinds of fire.5. which do not produce smoke particles. 7. kitchen. optically active.) Heat detectors are not suitable for detection in life safety installations and in slow burning / air-conditioned premises.) and in other unsupervised spaces / areas with low value contents. smoke detectors give faster responses than heat detectors.05 dB / m (visibility falls below 20m.2. Both types of smoke detectors have sufficiently wide range of response for general use.4. Optical smoke detectors are more sensitive to the larger. but may be more liable to give false alarms. Ionisation smoke detectors are suitable for detection of rapidly burning fires In a life safety situation it is essential to pay primary attention to early detection of smoke and to protect escape routes. IITK-GSDMA-Fire 05-V3. pantry etc. certain grades of petroleum fires etc. Heat detectors are suitable in compartments / areas where heat producing equipment are used (eg. The main characteristics of different types of fire detectors are enumerated below.
) are given in relevant national/international Standards like IS : 2189 : 1999. in turn. Detailed guidelines for selection. are connected to Control and Indicating equipment(C&I) (ii) The protected area should be divided into zones. (iv)One of the chief objectives of zoning is to make it easier to determine the location of fire.4. selection/choice of fire detectors etc. system design and maintenance etc. NFPA-72 : 2002 etc. eg. (vi)The distribution of fire alarm sounders should be such that they have a minimum sound level of either 65 dB (A) or 5 dB(A) above any other noise likely to persist for more than 30 secs. BS : 5839 : Part-1 : 1988.0 Page 80 . at pumps.6. (i) The systems consist of fire detectors and manual call points connected by cables to sector / zonal panels which. to 1000Hz. liftwell. or for critical areas where flaming fires may spread very rapidly. and that the alarm is heard at all designated locations in the building. (for fire detection and alarm systems for buildings. each zone covering only one storey of the building or any other prescribed area like stairwell. General requirements for automatic fire detection and alarm systems. and for general surveillance of large open areas in warehouses etc. IITK-GSDMA-Fire 05-V3.. installation. other vertical shafts etc. whichever is greater. 7. (v) The sounders for the fire alarm should be electronic hooters / horns / electric bells having frequency range of 500 Hz.Handbook on Building Fire Codes Heat detectors with rate-of-rise elements are more suitable where ambient temperature is low or vary only slowly. (iii)Individual zones/sectors are necessary if the number of detectors in any area exceeds 20. Flame detectors are particularly suited for outside applications.. valves or pipe work containing flammable liquids etc. while fixed temperature detectors are more suitable where the ambient temperature is likely to fluctuate rapidly over short period.
In this case. The C&I equipment. Copy of the Fire Orders for the premises should be prominently displayed. It should have preferably an independent A/c system. It should have intercom and direct telephone facilities. It should have emergency lighting system. where the following facilities should be made available: The Control Centre should have an area of approx. while the alert signal will be sounding in all areas.. IITK-GSDMA-Fire 05-V3. should be maintained in the Centre. the evacuation signal will be restricted only to the floor area as well as other areas immediately affected by the fire. (x) A Control Centre should be provided especially for high rise and special buildings. power supply units. drinking water facilities and other appropriate furniture etc.20m2. preferably in the ground floor. All relevant records etc. (ix)In large and / or high rise buildings and / or special buildings it may be necessary to have two-stage alarms for facilitating evacuation of the areas involving greater life hazard. 16m2 . It should have a mimic panel of the premises protected and all the fire protection systems. It will be desirable to have a direct hot line to local Fire Brigade Control Room. The Centre should be manned 24 hours by trained competent fire and / or security staff.0 Page 81 . and other fire protection ancillary panels should be installed in the Control Centre.Handbook on Building Fire Codes (vii) A multi-state addressable analogue detector system is designed to reduce the incidence of false alarms. It should have attached WC bath.
Handbook on Building Fire Codes 7.5 FIXED FIRE EXTINGUISHING SYSTEMS / INSTALLATIONS 7. Portable fire fighting equipment like fire extinguishers. (ii) Automatic Halon Alternative extinguishing systems IITK-GSDMA-Fire 05-V3.1.1. as well as mobile fire fighting equipment like Fire Tenders and other vehicle-mounted fire fighting appliances. Automatic foam installations using high expansion foam. Automatic foam installations using medium expansion foam. 7. General 7. (c) Systems/Installations using dry powder: (d) Systems/Installations based on clean gaseous extinguishing agents: (i) Automatic Halon extinguishing systems.2. Systems/Installations based on foam: Automatic foam installations using low expansion foam. On the other hand.5.0 Page 82 . structures or in specific areas.5. fire extinguishing systems installed permanently within the premises will be required for providing adequate fire protection. These fixed fire extinguishing systems/installations can be based on various extinguishing media used for protection. can be used for tackling fires whether inside a building or in the open.1. Automatic Water Spray Installations. Automatic Sprinkler Installations. (c) Systems/Installations using CO2: (i) Automatic CO2 installations (High Pressure Type). (ii) Automatic CO2 installations (Low Pressure Type). for tackling fires particularly inside buildings.1.5. as stated below: (a) (i) (ii) (iii) (iv) (b) (i) (ii) (iii) Systems/Installations based on water: Hydrant Installations. Automatic Deluge and Drencher Installations.
or series of buildings or other associated fire risks. Extinguishing agent: The substance contained in a fire-extinguishing system. Storage hazard: The general dangers of storage of goods.Handbook on Building Fire Codes 7. Foam inlet: Fixed equipment consisting of an inlet connection. fixed piping and a discharge assembly.5. when discharged on to the fire. 2. 4. and comprising a valve and outlet connection from a water supply main. 11. 8. is intended to produce extinction. usually by mechanical means. 10. 3. 7.2. and that feeds hydrants. e. Process hazard: A hazard associated with an industrial process involved in the manufacture or treatment of an end-product. etc. 6. fitted with inlet connections at Fire Service IITK-GSDMA-Fire 05-V3.Dry rising main: A vertical pipe installed in a building for fire-fighting purposes. having regard to their fire grading. Hazard: A particular area or activity in which a danger of fire can occur. determined by the standard of a building. storage etc. cotton pickings and carding machinery or heat-treatment bath. its usage and the quality of its fire protection. Definitions 1. paint spraying plant. 5.0 Page 83 . internal rising mains. flammability. Underground fire hydrant: An assembly contained in a pit or box below ground level.Ring main system: A water main that encircles a building. High-racked storage: A storage in which goods are held on high racking so that they are accessible for loading and withdrawal.g. enabling the Fire Service to introduce foam into an enclosed compartment. method of packing. Pillar fire hydrant: A fire hydrant whose outlet connection is fitted to a vertical component projecting above ground level 9. Risk: A measure of an insurer's probable liability.
that operates automatically at a predetermined temperature and discharges water in a regular pattern over the area below it.0 Page 84 .Wet rising main: A vertical pipe installed in a building for fire-fighting purposes. usually by pumping from Fire Service appliances.Landing valve: An assembly comprising a valve and outlet connection from a wet rising main or dry rising main.Wet system: A sprinkler system that is intended for use in locations where the ambient temperature is always above the freezing point of water. 13. Alternate system: A sprinkler system that may be used either as a wet system. 12. These classes and sub-classes are: (a) light hazard. The sprinkler pipe work is charged with water in the operational condition. which is normally dry but is capable of being charged with water. Pre-action system: A sprinkler system in which the sprinkler pipe work is normally charged with air at a low pressure up to the IITK-GSDMA-Fire 05-V3. The sprinkler pipe work is charged with air in the operational condition. 17. according to the hazard they present. Dry system: A sprinkler system that is capable of being used in any normal ambient temperature. or as a dry system in conditions where freezing temperatures may occur. where freezing temperatures do not occur. (c) high hazard (divided into process risks and storage risks) 15. that is permanently charged with water from a pressurized supply and fitted with landing valves at specified points. group II. group III special). 19. 14. or where part of the system may be exposed to them. 18.Sprinkler: A device that seals an aperture in the pipe work of a sprinkler system. (b) ordinary hazard (divided into group I.Classification of occupancies (for sprinkler systems): The division of occupancies into classes and sub-classes. 16.Handbook on Building Fire Codes access level and landing valves at specified points.
the water boils and expands suddenly. When the alarm valve opens. Design density of discharge: A measure of the average quantity of water falling per unit area per minute from a sprinkler system in full operation. in which the hot zone is sufficiently deep to reach the water that has drained to the base of the tank. This is generally used to protect large buildings against large flammable liquid spillages. Slop over: The condition that occurs when a water spray (or foam) is applied to the surface of a burning liquid that has developed a hot zone beneath the surface at a temperature in excess of 100oC. 20. 23. similar in principle to a sprinkler system. over an assumed maximum area of operation. Deluge system / Installation: An installation fitted with open spray nozzles controlled by a single deluge valve and operated on the actuation of automatic fire detectors so that the entire area is sprayed with water or foam as the case may be. causing some of the flammable liquid to pour over the rim of the tank. 26. On passing through this zone. so that a large part of the contents of the tank are expelled violently when the water boils.0 Page 85 . or to provide cooling to an exposed area likely to be subjected to intense heat radiation from a neighbouring fire. Water spray system: A system. 22. Oil processing areas.Handbook on Building Fire Codes sprinklers. Expressed as a rainfall. The installation can be controlled manually also. eg. Spray systems range in size from very small to very large. and in which the alarm valve is opened in response to an electric signal from a separate detection system.. the water discharges without delay from the opened sprinklers. 25. Assumed maximum area of operation: The maximum area over which a sprinkler system in full operation is required to maintain IITK-GSDMA-Fire 05-V3. the water from the supply compresses the air in the pipe work and approaches close to the sprinklers. Aircraft hangars. Bund fire: A fire in flammable liquid fuel that has leaked into the bund area surrounding a flammable liquid storage tank. 24. i. Boil over: A more severe condition than slop over.e. On sprinkler operation. mm/min. Tanker loading bays etc. that is designed to extinguish flammable liquid risks. 21.
29. methane. With each class and sub-class of sprinkler system.0 Page 86 . Liquefiable petroleum gases (LPG): Those flammable gases derived from the hydrocarbon series. then the permissible pipe sizes and pipe lengths.g. but vaporize on release to atmospheric pressure. 27. Total flooding: The discharge of a gaseous extinguishing agent into an enclosure. there is a related design density of discharge and assumed maximum area of operation. to a concentration sufficient to extinguish fire at those local areas. Recommended extinguishing concentration: The concentration of a gaseous extinguishing agent necessary to ensure extinction of flaming combustion throughout a protected enclosure. Modular total flooding systems: Those systems comprising one or more units released simultaneously within an enclosure.Handbook on Building Fire Codes the design density of discharge. 28. Local application: The discharge of a gaseous extinguishing agent at local areas of risk. to give a known total rate of discharge and concentration of the gaseous agent. 32. Liquefiable natural gases (LNG): Those flammable gases that can be retained as a liquid/vapour mixture in pressure vessels. They may or may not be piped systems. e. It depends on the type of agent used and the nature of the combustible. 30. but vaporize on release to atmospheric pressure. Inerting concentration: The concentration of a gaseous extinguishing agent necessary to ensure that combustion cannot occur throughout a protected enclosure. to a concentration sufficient to extinguish fire throughout the entire volume of the enclosure. NOTE: If they are piped systems. propane and butane that can be retained as a liquid/vapour mixture in pressure vessels. 33. 31. The inhibiting concentration is usually higher than the recommended extinguishing concentration. IITK-GSDMA-Fire 05-V3. The value of the recommended concentration depends on the type of agent used and the nature of the combustible. and the number and type of fittings and nozzles have to be specified by the manufacturer.
IITK-GSDMA-Fire 05-V3. The base unit may be fixed at one place. and reaches the branch as expanded foam. 40. and is fed through a piped system to nozzles located to discharge simultaneously on to specific areas of risk.Local application systems: Those systems in which the gaseous extinguishing agent is retained in a centralized supply tank or cylinder bank. but mounted on a swivelling base. Surface application: The application of made foam to the surface of a flammable liquid to form a blanket. and is fed through a piped system to manual hose reels located at specific points adjacent to the main areas of risk. Manual hose-reel systems: Those systems in which the gaseous extinguishing agent is retained in a centralised supply tank or cylinder bank. 35. Engineered total flooding systems: Those piped systems fed from a centralised tank or cylinder storage tank to give a known total rate of discharge and concentration of the gaseous extinguishing agent within the enclosure. 41. total discharge time and the nozzle locations and nozzle pressures to ensure the best arrangement to suit the type and distribution of combustibles within the enclosure. Foam pourer: A device for discharging made foam on to the top of flammable liquid in a storage tank. so that it floats to the surface and spreads on it to form a foam layer.Handbook on Building Fire Codes 34. Sub-surface application: The application of made foam beneath the surface of a flammable liquid. 37. NOTE: They require individual design and calculation to determine flow rates. except that it does not induce the air. or may be trolley mounted or vehicle-mounted. so that its greater output can be discharged without reaction on the operator. and is bolted through the wall of the tank to the top so that it can discharge on to the flammable liquid surface. since the foam has been made further upstream at an in-line generator. Foam monitor: A similar device in principle to the foam branch or foam branch pipe. 36. The pourer is usually fed from a foam riser. Foam branch: A similar device to a foam branch pipe. 38.0 Page 87 . 39.
the kinetic energy possessed by the moving water is instantaneously converted into pressure energy which results in a sudden shock and generation of pressure waves through the column of water. the pressure and flow rate of which is predetermined. or combinations of these are normally produced. Modular systems: Systems that comprise one or more storage units that all discharge simultaneously through their own outlet nozzle. 45. Explosion: Is a physical or chemical change resulting in the sudden. which are located to suit the nature and distribution of the combustible.0 Page 88 . the permissible pipe sizes and pipe lengths. Water hammer: If water flow in a pipe is shut off suddenly. 42. They are individually calculated and designed to give the required flow rates to each of the individual discharge nozzles. Semi sub surface application: The application of made foam to the surface of a flammable liquid in a storage tank through a flexible plastics stocking that. and the latter tends to recoil in the opposite direction to the flow. Jet reaction: When water is projected from a nozzle. light. 46. Engineered systems: Piped systems from a centralised cylinder storage bank. This is known as water hammer. This is known as the jet reaction (if the size of the nozzle is doubled. a reaction equal and opposite to the force of the jet takes place at the nozzle. 44. without it having to have contact with the flammable liquid. or impossible. the reaction increases to four times. violent release of energy heat. making it much more difficult. gaseous products and shock waves. for one man to hold the branch). 47. They may or may not be piped systems. and the number and type of fittings and nozzles have to be specified by the manufacturer for each unit. IITK-GSDMA-Fire 05-V3. 43. although the injection point may not be right at the base of the tank. NOTE.Handbook on Building Fire Codes NOTE: Also called base injection. Chemical explosives may either deflagrate or detonate. If they are piped systems. on injection of foam. unrolls and floats to the surface so that its sealed end is burned off and releases the foam directly at the surface.
friction or percussion.3. 7. This fire fighting water is usually obtained from hydrants installed on public mains or other premises.3. burning of propellants (low explosives). which may be laid underground or above ground. Explosion often produces a shock wave.0 Page 89 . 7.5.3. (c) Pipelines.3. sound and flash. HYDRANT SYSTEMS / INSTALLATIONS 7. The basic requirements of any hydrant systems are: (a) Water reservoir or source of water supply (for supply of water for fire fighting purposes). where the hydrants are installed in the open.3.Handbook on Building Fire Codes 48. Deflagration: A form of rapid burning accompanied sometimes with a mild explosion.2. major fires have to be controlled and extinguished by the use of water from fire fighting hoses operated by the regular fire services. like the city or town water mains. installed in buildings or structures to be protected 7. Explosives: Are chemical substances or combination of chemical substances which are liable to explode due to heat. 51.5. Hydrant Systems can be of two types: (a) External Hydrant System. (b) Pump(s) for imparting energy to the water (for conveying water through pipe lines. for conveying water under pressure to the required places. or hydrant systems installed in the open areas in industrial or such other occupancies. and to make water available at the required pressures for fire fighting purposes). 49. 50. spark. IITK-GSDMA-Fire 05-V3. Water being the main extinguishing medium.1. Implosion: Is a special case of failure of a sealed evacuated vessel / container as a result of differential pressures. The detonation of a high explosive is always accompanied by brisance or shattering effect. Detonation: Are violent explosions with shock waves which travel at sonic or supersonic velocities (sonic velocity is 300 m / sec). Eg. and (b) Internal Hydrant System. and evolves large quantities of heat.5.5.
For instance.3. and subject to a minimum of one. for fire fighting purposes.4. External Hydrant Systems: (a) These systems are essential and important requirements for fighting fires in cities. Provision has to be made for standby pumps fed from a different source of power at the rate of 50% of total number of pumps. The guidelines for provision.5kg/cm2 (20psi) should usually be maintained at hydrants delivering the required fire flow. a high pressure system has been provided which has a fire flow of 20. (b) The guidelines regarding the water reservoirs and such other details for water supply are given in IS:9668-1991. IITK-GSDMA-Fire 05-V3. A few other cities in US also have provided similar systems. installation. The system was provided primarily because an earthquake can put the regular public water system out of service.000 gpm at 250 psi delivered to most of the principal mercantile districts. a separate system designated 'high pressure system' is maintained under the control of the fire department which is utilised for fire fighting purposes only. inspection and maintenance of these systems are given in IS:13039-1991. A minimum residual pressure 1.5. 'Code of Practice for Provision. (c) The capacity of pumps required for these systems have to be worked out based on requirements of output and pressure for the systems. US. using delivery hoses. The static fire fighting pumps should conform to the requirements given in IS:12469-1988.Handbook on Building Fire Codes (d) Hydrants (which are the outlets installed on the pipelines at strategic locations on the water mains for drawing water. In some foreign countries. in San Francisco. and Maintenance of External Hydrant System'. tar coated and lined. towns and individual occupancies or premises. All the pipes are of heavy cast iron. 7.0 Page 90 . 'Pumps for Fire Fighting Applications' (d) Pressure requirements of systems The pressure for systems are normally designed based on practical considerations and specific needs. and tested to 450 psi. 'Code of Practice for Provision and Maintenance of Water Supplies for Fire Fighting'.
on a fire call. or separate fire fighting water mains. as in some cities) do exist in all cities and towns. which may be required for tackling major fires. well maintained hydrant water mains (which may be either a combined system for domestic as well as for fire fighting purposes. there are hydrants available even now in some roads and streets. we do not have such reliable hydrant water mains even in our metropolitan cities. and added IITK-GSDMA-Fire 05-V3. and many of them are either un-serviceable. (ii) As compared to the above in India. Govt. is designed to meet broadly the following requirements: Minimum size of distribution main is kept as 100 mm (as against 150 mm in many foreign countries) For fire fighting purposes. they cannot be taken in to account for availability for fire fighting purposes. not to speak of towns. Consequently. sometimes even for several hours. or not presently traceable due to constructional changes in between. No doubt. In practice. According to this. (iii) The existing water supply arrangements for our cities and towns are generally based on the formulae recommended in the Manual on Water Supply and Treatment issued by the Ministry of Works and Housing.Handbook on Building Fire Codes (e) Indian scenario (i) In other developed countries. These fire fighting mains are capable of providing non-stop fire flow of even upto 20. the system. of India. in some of the cities. most of our city fire brigades are forced to maintain a large fleet of heavy Water Tenders / Tankers for replenishment of their fire fighting vehicles. This arrangement is no substitute for having regular fire fighting water mains. However. connect up to the hydrants. each capable of delivering 450 lpm for about 4 hrs. at least 4 streams. no separate provision is made in city water supply for fire fighting purposes while calculating per capita consumption of water. which can only guarantee continuous supplies of water for fire fighting purposes. report to the scene.5 kg/cm2.0 Page 91 . should be available within reasonable distance 'with pressure' of 1kg/cm2 to 1. These hydrant mains were installed during the pre-independence periods. draw water from them. each of 900 lpm. Fire service vehicles. In major towns this may be increased to 6 to 8 streams (In foreign countries like USA the fire fighting water mains are of much larger diameter and capable of handling bigger fire flow rates for operation of 25 streams or more. in some major cities.000 gpm or more. and carry out fire fighting operations. sometime back.
friction loss is reduced to one-quarter). For the same velocity.0 Page 92 . As per the Manual. The fire fighting operations may continue for several hours also without any interruption). the friction loss will be reduced to one-half.Handbook on Building Fire Codes pressures ranging from 5kg/cm2 to 8-10kg/cm2.000 40. the friction loss will also be doubled). Capacity of fire fighting reservoirs in m3 or kilo litres 50 100 200 300 350 400 IITK-GSDMA-Fire 05-V3. Friction loss increases directly as the square of the velocity (if the velocity of the water is halved.000 (f) Pressure and flow in mains (i) The pressure of water flowing in the water mains can be expressed either in kg/cm2 or bars (1atmosphere = 14. The five principal laws governing the loss of pressure due to friction in hoses or pipes are: Friction loss varies directly with the length of the pipe (for double the length of hose.5 to 2 lakhs.013 bar) (1 bar = 100kN/m2).000 50. While flowing through the hose or pipe some loss of pressure is experienced due to friction loss.325 kN/m 2 or 1.000 20.7psi or 101.000 30. Population of less than 5000 10.0981 bar) (ii) The amount of water a hose or pipe will transmit or convey in a given time depends on its size (cross-sectional area) and its velocity of flow. even for a city of population of 1. or as meters head (1meter head = 0. the following amounts of water are to be provided in the service reservoirs for fire fighting. but the quantity of water is increased to four times). friction loss decreases directly with the increase in diameter(If the diameter of the hose is doubled.
(g) A distribution system for water supplies generally consists of: (i) (ii) Water mains (trunk. or sedimentation. The relative increases are indicated as under: Size of pipe.0 2. Friction loss. is independent of pressure. incrustation.2 9. This allows hydrants and other connections to be fed from at least two directions and greatly increases the water flow without excessive friction loss.0 Page 93 . IITK-GSDMA-Fire 05-V3. because of tuberculation. for all practical purposes.1 3. secondary and service mains) Service mains (used for supply to premises from the streets) (iii) Service reservoirs (including overhead tanks. water towers etc.8 6.) (iv) Booster pumps (at intermediate points where the length of the mains is excessive) (h) Water Mains-Broad Features Increasing the pipe diameter increases water flow. The addition of cement lining usually retards or prevents such deterioration. inches 6 8 10 12 14 16 Relative capacity 1.2 Pipe systems should be arranged in loops wherever possible.Handbook on Building Fire Codes Friction loss increases with the roughness of the interior of the pipe/hose.3 13. Plastic pipes (approved unplasticised PVC class 4 pipes are being installed increasingly and are immune from tuberculation and corrosion problems). In course of time the internal cross section of cast iron pipe may be reduced or its interior surface made coarse.
Forces acting on pipe laid in the ground are mostly internal static pressure of the water. minimum period. IITK-GSDMA-Fire 05-V3. water hammer. Buried pipe needs a coating to protect against soil corrosion. load from the back fill. Cathodic protection methods are widely used for the external protection of iron and steel water mains. Duck foot bend. and female couplings with blank caps are normally provided for internal private hydrants). (ii) There are two types of hydrants . Flange riser Stand post column fitted with one (single headed) or two (double headed) 63mm male couplings (male couplings with blank caps are normally provided for city or street hydrants. at not less than 1. and is now being used in place of cast iron.0 Page 94 .5 times the working pressure for not less than 2 hrs. Cathodic protection is a technique of imposing direct electric current from a galvanic anode to the buried pipe line. or underground type(sluice-valve type) (iii) Stand-post type hydrant . and load and impact from passing trucks and other vehicles. The water main is provided with a branch or T-piece to which the hydrant is attached either directly or with a short length of pipe. Road surface boxes. All pipe lines should be subjected to hydrostatic pressure tests.General requirements: Shall have one or two sluice-valves.Handbook on Building Fire Codes Ductile iron pipes have the corrosion resistance of cast iron and almost the same strength and ductility of steel. (j) Fire Hydrants (i) Fire hydrants provide the means of drawing water from the water mains for fire fighting.stand-post type.
in the case of private systems.Handbook on Building Fire Codes Figure of stand-post type hydrant given below: Fig-27 Stand-post type Hydrant Note: Generally. water flowing horizontally past the sluice valve IITK-GSDMA-Fire 05-V3. (iv) Underground type of hydrants (Sluice Valve Type)-General Requirements These hydrants are placed underground alongside the water mains on a short branch. fire hoses can be directly connected to the hydrants and fire fighting operations can be carried out without delay. Spare rubber washers for the couplings. Since the water mains are charged. a hose box or cabinet will also be provided which usually contains the following items: Two lengths of 63 mm fire fighting hose conforming to Type A of IS:636-1988 with couplings. One universal branch pipe conforming to IS:2871-1983 (jet and spray branch).0 Page 95 . beside each stand-post type hydrant.
hydrant key. the dimension of the sluice valve as well as the hydrant connection will have to be of 100 mm diameter in order to provide the required fire flow through the hydrant. For operating the hydrants certain hydrant fittings are required such as hydrant stand pipe. the inlet piece which is connected to the pipe. IITK-GSDMA-Fire 05-V3. For locating the hydrants. hydrant bar etc. prominently marked hydrant plates are provided on the ground surface.0 Page 96 .Handbook on Building Fire Codes Note: The hydrant consists of three main castings. hydrant cover key. Typical figures of the underground sluice valve type of hydrant and hydrant box are shown below: Fig-28 Underground Hydrant-Sluice valve type Fig-29 Typical Hydrant Box Note: In case double headed hydrant stand pipes are used. the sluice valve itself and the duckfoot bend leading to the outlet. water iron.
hydrants should be provided at intervals of 100m. a minimum running IITK-GSDMA-Fire 05-V3. For high hazard occupancies.. and the other half in the most vulnerable area enroute. Fire fighting mains in industrial premises should not be utilised for any other purpose such as process use etc. The fire hydrant mains should always be laid in rings or loops. the hydrant system shall be so designed that when half the aggregate pumping capacity is being discharged at the farthest point. Hydrants should be readily accessible to fire appliances and for fire fighting operations.Handbook on Building Fire Codes (k) Other factors to be taken into consideration in the provision and use of external hydrant systems: Minimum size of mains should be not less than 150 mm. Underground mains should be laid not less than 1m below ground level. (details of the tests and maintenance of the systems are given in IS:13039-1991. In case of industrial premises. but this can be varied according to the risks in the area. and for industrial establishments.5m. Adequate number of shut-off valves (isolation valves) should be provided at strategic locations in the system for the purpose of isolating any portion for maintenance. Testing of pressure and output in different areas covered by the system should be carried out atleast every quarter. For systems in cities and towns hydrant inspection should be carried out at intervals not exceeding one month. 45m for moderate hazard occupancies and 60m for light hazard occupancies. repairs etc. Above ground mains should be adequately supported at regular intervals not exceeding 3. No portion of a protected building should be more than 45 m from an external hydrant. 'Code of Practice for Provision and Maintenance-External Hydrant Systems'. the intervals for hydrants can be 30m for high hazard occupancies.0 Page 97 . once every week. Normally in cities and towns.
0 Page 98 .25 kg/cm2. the fire fighting pumps are each of the following capacities: 290 17400 1044 (3828gpm) IITK-GSDMA-Fire 05-V3.. in Jamnagar. Water monitors fixed at strategic points in the hydrant system can be of various sizes with various outputs as given below: Size of monitor inlet 63mm 75mm 100mm Size of monitor outlet (nozzle dia) 32mm 38mm 45mm Output(lpm) 1750 2580 3500 Pump Capacities of Hydrant Systems(for private systems only): The capacities of pumps for hydrant systems can vary according to the risks to be covered.25 kg / cm2 is available at the former point and rate of flow of water does not exceed 5 m / sec. Litres/sec.5kg/cm2. Minimum output of hydrants is generally accepted as 1125 lpm (250gpm) at a minimum pressure of 5. the pressure requirement at the most remote point can be restricted to 3. 96 137 171 273 410 Note: In an extra high hazard industry. like Reliance Petroleum Ltd. For ordinary / light hazard occupancy. anywhere in the system. 1620 2280 2820/2850 4560 6840 M3/Hr.Handbook on Building Fire Codes pressure of 5. INTERNAL HYDRANTS 27 38 47 EXTERNAL HYDRANTS (INDUSTRIES) 76 114 Litres/min.
Handbook on Building Fire Codes 7. and (iv) Down-comer-system Dry riser system is not normally charged with water but could be charged either through the fire service inlet provided at the bottom. An internal hydrant installation comprises of the following elements: (i) (ii) Static or terrace tank for storing water for fire fighting purposes. Internal hydrants form part of any of the following systems(i) Dry-riser system. hoses and branch pipes. Generally. Rising mains. This system is normally charged by the operation of the static fire fighting pump installed in the building. A wet riser system remains charged throughout so that by connecting delivery hoses.0 Page 99 . (b) The main features and requirements for the internal hydrant systems are listed below: The capacities of the underground static water tanks/ terrace tanks vary according to the fire risks involved in the occupancy.5. IITK-GSDMA-Fire 05-V3. However. or through an installed pump when required. (ii) Wet-riser system. Internal Hydrant Systems (a) These systems are generally installed for fire protection of buildings or special structures. The fire service inlet for 100mm internal dia rising main should have a collecting head with 2 nos. in cabinets. (iii) Fire fighting pump(s) with all fitments and components. external hydrants (also called as yard hydrants).should have a collecting head with 4 nos. or directly from a fire appliance. of 63mm inlets. (iii)Wet-riser-cum -down-comer system.5. hose reels are also connected to this system alongside landing valves. of 63mm inlets. and (iv) Other necessary components like internal hydrants (also called as landing valves. hose reels. fire fighting operations could be carried out immediately. down comer mains or external mains to feed water from the source to the required point under pressure. The landing valves provided in the system are required to be sited so as to ensure that no part of the building protected is more than 30m from the landing valve.3. and for 150mm rising main. a fire service inlet is also provided for charging it from fire service appliances.
Handbook on Building Fire Codes
The down comer system is connected to a terrace tank through a terrace pump; In addition to wet riser systems, first aid hose reels are required to be installed on all floors of high rise buildings or special type of buildings. The hose reel is generally taken directly from the rising main by means of a 37mm socket and pipe to which the hose reel(generally of 19mm dia) is attached; The internal hydrant system should conform to IS:3844 1989, "Code of Practice for Installation and Maintenance of Internal Frie Hydrants and Hose Reels on Premises". The hose reel should conform to Type-A of IS:884-1985, "First-aid hose-reel for fire fighting"; For a wet-riser system, two automatic pumps should be installed to independently feed the wet-riser main, one of which should act as stand-by, each pump being supplied by an independent source of power. However, an interlocking arrangement will ensure that only one of the pumps operate at a time; For bigger systems, it is desirable to instal a small pump of approx. 180-300 lpm capacity, with pressure switches for automatic start and stop, which is known as jocky pump; The system should be tested before use for a minimum pressure of 7kg/cm2 for at least 30 min., after which a flow test should also be carried out; Details of periodical tests and maintenance etc. are given in IS:3844 1989, and also in Fire Protection Manual (12th eddition -1998) issued by Tariff Advisory Committee (TAC). 7.5.4. AUTOMATIC SPRINKLER SYSTEMS 22.214.171.124. General Automatic sprinklers are devices for automatically distributing water upon a fire in sufficient quantity to extinguish it completely or to prevent its spread, by keeping the fire under control, by the water discharged from the sprinklers. The water for fire fighting is fed to the sprinklers through a system of piping, normally suspended from the ceiling, with the sprinklers installed at intervals along the pipes. The orifice of the sprinkler head, incorporating the fusible link or fusible bulb of the automatic sprinkler, is normally kept closed, which is thrown open on the actuation of the temperature-sensitive fusible link or fusible bulb.
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The figure depicting the lay out of a typical sprinkler installation is given below:
Fig-30 Layout of a Typical Sprinkler Installation
Automatic sprinkler systems are quite effective for ensuring life safety, since they give early warning of the existence of fire and simultaneously start application of water on to the fire which will help control and extinguishment of the fire. The downward force of the water spray from the sprinklers also help minimise the smoke accumulation in the room of fire besides cooling the environment and promoting survival of the occupants. NBC Part-4, Fire and Life Safety, also recognises the importance of sprinklers for achieving fire and life safety. The provision of the sprinkler system in buildings helps to offset deficiencies in fire protection requirements in existing buildings and the Code provides 'trade-offs' in the matter of various fire protection requirements when automatic sprinkler systems are provided. For eg., longer travel distances to exits, higher fire load density etc. are allowed with the provision of sprinklers.
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However, it has to be mentioned that partial coverage of the buildings by sprinkler protection is neither advisable from fire protection point of view nor from cost effectiveness. In case a fire originates from an unprotected area and after growing into a well developed fire spreads to the protected area, it would have generally developed sufficient intensity to overpower the sprinklers. 126.96.36.199. Types of Sprinkler Systems: There are four main types of sprinkler systems: Wet - The pipes are permanently charged with water and used for all locations except where freezing temperatures are likely to occur or special conditions exist. Dry - The pipes are normally charged with air under pressure. Alternate - Can be arranged to be either wet or dry depending upon ambient temperature conditions. Pre-action - The pipes are normally charged with air, and get filled with water when a fire actuates a separate detection system. Sprinkler heads then operate individually. 188.8.131.52. Classes of System as per Fire Hazard: There are three classes of systems based on the fire load of the occupancy to be protected. The design densities of discharge and the assumed maximum area of operation for the three classes are as given below: Type of System Design density of discharge 2.25 lpm/m2 5.0 lpm/m2 Assumed maximum area of of operation 84m2 360m2
Low Hazard System(LH) Moderate Hazard System (MH) High Hazard System(HH) (a) Process risks (b) High piled storage risks
7.5/12.5 lpm/m2 7.5/30 lpm/m2
260m2 260/300 m2
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18.104.22.168. Water Supplies: It is essential that sprinkler systems are provided with a suitable and acceptable water supply. The Rules accept the following sources subject to certain specific conditions: town mains elevated private reservoirs gravity tanks automatic pump supply pressure tanks 126.96.36.199. Sprinkler Heads: Their operation can be divided into two main types: (i) Those in which the operating medium is fusible solder; and (ii) Those in which the operating medium is a glass bulb (quartzoid bulb). (iii)Fusible solder type: In this type the body of the sprinkler is held in place by two yokes and a flexible metal diaphragm into which a valve is fitted. Three parts, viz., the strut, the hook, and the key are held together by a special fusible solder. In a fire condition the fusible solder (or link) melts and the component members are thrown clear of the head, allowing the water to flow out in the form of spray after hitting the deflector.
Fig-31 A typical fusible solder type sprinkler head showing component parts
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(iv)The solders used with automatic sprinklers are made of alloys of metals like tin, lead, cadmium etc. (v) Fusible bulb type: The second type of operating element of the sprinkler head utilises a frangible bulb. In this, a small bulb of special glass contains a liquid leaving a small air bubble entrapped in it. When exposed to heat from fire, the liquid expands and the bubble disappears. Due to increase of pressure the bulb shatters, releasing the water in the form of spray. The operating temperature is regulated by adjusting the amount of liquid, the nature of the liquid itself, as well as the size of the bubble.
Fig-32 A typical fusible bulb type sprinkler head showing component parts
184.108.40.206. Temperature Ratings of Automatic Sprinklers: Automatic Sprinklers have various temperature ratings that are based on standardised tests in which a sprinkler is immersed in a liquid, and the temperature of the liquid raised slowly until the sprinkler operates. All heads are marked with their operating temperature ratings, and are colour coded for easy identification. Temperatures and colours are as follows:
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0 Page 105 . (c) Ceiling flush pattern: The heads are installed with the base flush to the ceiling. These are commonly used for guest room fire protection in hotels. Moderate Hazard and High Hazard. (b) Spray pattern: This operates with a hemispherical discharge pattern below the deflector with no water being directed upwards. The pipe work remains concealed above the ceiling. (d) Side wall pattern: These are installed along the walls of a room close to the ceiling.4.7. 7. (e) Dry upright pattern: These are the same as pendent type sprinklers. and heat sensitive elements facing downwards. which are generally used respectively for Light Hazard. and produces a horizontal pattern of spray.Handbook on Building Fire Codes Sprinkler Temperature Rating 57oC 68oC 79oC 93oC 141oC 182oC 204 to 260oC Bulb Type (Colour of Bulb) Orange Red Yellow Green Blue Mauve Black Fusible Link Type Uncoloured White Blue Yellow Red (227oC) Orifice Size The sprinkler orifice sizes are 10 mm. but this may vary according to the spray pattern and type of head used. and 20 mm. They may be of upright or pendent type. Types of Sprinklers The following are the types of sprinklers which are accepted for general use: (a) Conventional Sprinkler: These produce a spherical type of discharge with a portion of the water directed upwards to the ceiling. IITK-GSDMA-Fire 05-V3.5. 15 mm.
5.Handbook on Building Fire Codes Fig-33 Types of sprinklers (bulb type) (1) Ceiling flush pattern (2) Sidewall pattern (3) Pendent type (4) Dry upright type 7. IITK-GSDMA-Fire 05-V3. (iii) Gravity tanks.0 Page 106 .8. Apart from primary water supply. (iv) Automatic pump supply or (v) Pressurised tanks.4. secondary water supply arrangements should also be made as stand by. (ii) Elevated reservoirs. Use of salt or brackish water is not permitted. Sprinkler Water Supplies: The water supplies for the sprinkler system must have adequate and reliable pressure and flow as per Sprinkler System Codes / Rules. The supplies may be by (i) Town's mains.
IITK-GSDMA-Fire 05-V3. The better performance of this type of sprinkler is achieved by increasing the diameter of the sprinkler orifice to 18mm allowing significantly more water to flow from one head. nearly 2 to 3 times as much as a standard head. Fire suppression is achieved by quickly discharging a large volume of water directly onto the fire to suppress it.4. 7.Handbook on Building Fire Codes Fig-34 Diagramatic lay out of pipework of a sprinkler installation. Early Suppression Fast Response Sprinklers(ESFR): ESFR type of sprinklers was developed in the late 1980s to meet the challenges of high-tech and complex fires.4. It differs from standard sprinklers in that it is designed to suppress or extinguish a fire in its early stages rather than control it.400 lpm.184.108.40.206 Page 107 .5 to 10 m2 7.5. The flow from one ESFR sprinkler is roughly around 375 . Area covered by sprinklers: The maximum area covered by a sprinkler in different hazard classes of occupancies are shown below: Hazard class Extra light hazard Ordinary hazard Extra high hazard General 21 m2 12 m2 9m2 Special risk areas or storage racks 9 m2 9m2 7.
(viii) It has been reported that in buildings where sprinkler systems have been installed the chances of fatal occupant casualties and IITK-GSDMA-Fire 05-V3. another type of sprinkler.Handbook on Building Fire Codes Testing in the US and in the UK has shown that. known by the term. This practically means that the installation is capable of dealing with a fire where upto 25 heads are operated. (vii)Sprinklers can only be effective if they activate before the fire gets past them. for which a sprinkler installation is designed. (iii) High rise system: Is a sprinkler system in which the highest sprinkler is more than 45 m above the lowest sprinkler/sprinkler pumps.density of discharge over an assumed maximum area of operation. the design point may be only 25. (v) Design point: A sprinkler installation is planned on the basis of a design point. (ii) Each system has to be hydraulically designed to provide an approx. whichever is lower.5.4. (vi) Work done at Factory Mutual showed that convective heat generally supplies more than 80% of the heat sprinklers need for activation.11. (iv) Low rise system: Is one in which the highest sprinkler is 45 m or less from ground level or sprinkler pumps. determined from the discharge of a specified group of sprinklers in lpm divided by the area covered in m2 . ESFR sprinklers offer probably the best form of automatic fire protection available for high hazard occupancies.) of water. Other important facts / features regarding Sprinkler Systems: (i) Design density of the system means the minimum density of discharge (in mm/min. This means the maximum number of sprinklers that may be operated at one time in case of fire. Though an installation may have 500 or even 1000 sprinklers.(no. if installed correctly. 'Quick Response Extended Coverage Sprinkler has also come into world market which responds quickly to fires with larger coverage areas upto 36m2.0 Page 108 . Like the ESFR. 7. of sprinklers likely to operate) in the highest and remote areas to be protected.
compared to buildings where sprinklers have not been installed.0 Page 109 . antiquated. 80% of fires were extinguished by the operation of eight or less sprinkler heads. IITK-GSDMA-Fire 05-V3. 94% of fires were controlled and extinguished by the operation of twenty one to twenty five sprinklers. Fires very close to people who can be killed before a system can react. provided the following statistics: 55% of fires were extinguished by the operation of two or less sprinkler heads. and. (ix) When sprinklers do not produce satisfactory results. (xii) International experience: An analysis conducted in UK of a large number of fires in sprinkler-protected premises. (x) If properly designed. Explosions or flash fires that overpower the system before it can react. poorly maintained or inappropriate systems. A statistical report released by NFPA for a 10 year period reveals: 55% of fires were controlled and extinguished by the operation of three sprinklers. installed and maintained. 80% of fires were controlled and extinguished by the operation of eight sprinklers.Handbook on Building Fire Codes property losses per fire are reduced to about two-thirds. (xi) In our country also. sprinkler systems remain the best option for providing cost-effective life safety and property protection. 90% of fires were extinguished by the operation of eighteen or less sprinkler heads. the reasons usually involve one or more of the following: Partial. Sprinkler coverage for fire protection of occupancies has full legislative as well as insurance support. TAC and Insurance Companies encourage the installation of sprinkler systems in buildings by giving substantial reduction in insurance premiums(even upto 50%) for buildings so equipped.
11. if the height of the building exceeds 30 m (45 m in case of group housing and apartments) (see Note). if so advised by local authority. A. hospitals. there is a real danger of a fire starting on one of the lower unsprinklered floors gathering momentum.5. mercantile buildings of height 15 m or above.4. (f) godowns and warehouses. (h) dressing room. plant and DG set. excluding any area to be used for sub-station.0 Page 110 . if the aggregate covered area exceeds 750 m2. It is desirable that all high rise buildings should be fully sprinklered irrespective of their height and occupancy.C. covered upper floors used as car parks. In such an event. (c) any room or other compartment of a building exceeding 1 125m2 in area except as in (g) (see Note). Use of false ceiling voids for storage or as return air plenums should be discouraged. (e) all non-domestic floors of mixed occupancy which constitute a hazard and are not provided with staircases independent of the remainder of the buildings. NOTES 1. (j) in hotels. spreading upwards from floor to floor through the unsprinklered floor and reaching the first sprinklered floor as a fully developed fire. IITK-GSDMA-Fire 05-V3.Handbook on Building Fire Codes 7. NBC): (a) basements used as car parks or storage occupancy. (k) in hotels below 15 m. (g) on all floors of the buildings other than residential buildings. and (m) canteen provided in upper floors of D-1 and D-2 occupancies shall be sprinklered. the sprinklers can be rendered useless or ineffective. If selective sprinklering is adopted. scenery docks. (b) multi-level basements. if the area exceeds 200 m2. 2. industries low and moderate hazard. as considered necessary. (l) false ceiling voids which are used for storage or as return air plenums exceeding 800 mm in height in sprinklered buildings (see Note 2). and for housing essential services ancillary to a particular occupancy or for storage occupancy. if covered area at each floor is more than 1000 m2. Automatic Sprinklers Shall be installed in (as stipulated in Part-4. stages and stage basements of theatres. (d) departmental stores or shops.
5. dilution (or removal) of the liquid fuel (starvation or emulsification).0 Page 111 . and for protection of openings in fire walls and floors. oil switches. piping.5. Types of water spray systems: There are two basic types of water spray systems installed as fixed systems. Exposure protection(cooling). and to IITK-GSDMA-Fire 05-V3. processes.Handbook on Building Fire Codes 7.2. One of these is used to extinguish oil fires and usually referred to as 'Water Spray Projector System'. a design discharge rate of about 13600 lpm (3000 gpm) is the limit for one system.1. The system can be operated automatically by connection to an automatic detection and alarm system or manually. rotating electrical machinery etc.5. pumping equipment.5. electrical equipment such as transformers. and Prevention of fire (cooling). General (i) Water Spray System is a special fixed pipe system connected to a reliable source of pressurised water supply and equipped with water spray nozzles for application on area / equipment to be protected. the other is mainly used to provide protection to plant. Water spray nozzles having very small water passages may have their own internal strainers. large quantities of water are required. (iii)The suppression or extinguishment of fire is achieved by cooling. dilution of oxygen supplies (smothering).5. (v) The type of water spray required will depend on the nature of the hazard and protection required.5. (iv)Water spray systems are generally used for fire protection of flammable liquid and gas storage tanks. or both. (vi)Size of the system: Since most systems perform as deluge systems. Normally. Control of fire. 7. (vii) Strainers are required to be installed in the supply lines of fixed piping spray systems to prevent clogging of the nozzles. equipment. WATER SPRAY SYSTEMS 7. (ii) These systems can be used for any one or more of the undermentioned purposes: Extinguishment of fire.
(a) High velocity system: This is generally used for extinction of fires in flammable medium and heavy oils or similar flammable liquids having a flashpoint above 65oC. The high velocity sprays of water are discharged through specially designed projectors.Handbook on Building Fire Codes prevent explosions. and is generally known as a 'Water Spray Protector System'. Fig-35 Two types of High Velocity Water Spray projectors The high velocity spray system for transformers should be well designed to have adequate coverage of the entire transformer unit including the conservation tanks. thereby achieving the smothering effect. Extinguishment is achieved by the three principles of emulsification. cooling and smothering. with the droplets of water travelling at high velocity. (eg: Transformer fires) The system projects water in the form of a conical spray.0 Page 112 . Some of the water droplets while passing through the flames get converted into steam. These systems can be operated either manually or automatically. The positioning of nozzles should be such as to protect all surfaces IITK-GSDMA-Fire 05-V3. the bushings and the bottom area.
maintenance etc. Normally.0 Page 113 . The water spray systems should have isolation facilities so as to enable periodic testing. all cut-off valves should be locked open. The system should be of pre-action type. Fig-36 Automatic Water Spray projector system Fig-37 High Velocity Water Spray System for Transformer Protection IITK-GSDMA-Fire 05-V3.Handbook on Building Fire Codes of the transformer and to give a discharge rate of not less than 10 lpm / m2 of the area to be protected.
so that the entire area to be protected is sprayed with water.2 lpm/m2 7.not less than 10.not less than 20. (b) Medium Velocity Water Spray Systems: (i) This system applies water in finely divided droplets at medium velocity. (iv) Application rates for water spray systems are as follows: For extinguishment -. Sometimes. The installation can be controlled manually also. This allows the water to flow out through the projectors in the form of high velocity water spray and extinguishes the fire. (iii) Operation can be done automatically as well as manually.6.8. It gives protection to tanks. and for cooling purposes IITK-GSDMA-Fire 05-V3.5. by controlled burning of flammable liquids and also by dilution of explosive gases. controlled by a single deluge valve and operated on the actuation of automatic fire detectors. These systems are provided where there is a concentration of highly flammable liquids like aircraft hangars.4 lpm / m2 (for protection of pumps.4 lpm/m 2 of protected surface. by cooling. This is mainly used for fire protection of areas with fire risks from low FP flammable liquids(FP below 65oC) and also for fire extinguishment of water miscible liquids (polar solvents.1 lpm to 20. (ii) These systems are similar in operation and lay out to the high velocity systems.Handbook on Building Fire Codes The high velocity water spray system for transformer protection operates on the same principle as a deluge system. thereby operating the deluge valve. or sprinkler heads. structures.0 Page 114 .5. Generally. glands other critical areas) For exposure protection (for cooling) -. AUTOMATIC DELUGE INSTALLATIONS: 7. The detectors mounted on a separate pipeline on detecting the fire releases the compressed air within the pipe. alchohols etc. equipments etc. tank farms filling gantries etc. These are installations fitted with open spray nozzles. additionally an electrical alarm may also be provided.). For fire control -. a water motor operated gong(as in the case of sprinkler systems) sounds the fire alarm.1.6.
1. 7.7.5. windows and external openings) protect buildings from damage by exposure to fire in adjacent premises. Fig-38 A typical deluge system 7. and it is desirable to apply water simultaneously over complete area. 7. The system comprises of drencher heads.2. which may be sealed or open (in the latter case water is turned on manually). Drenchers are of three main types: IITK-GSDMA-Fire 05-V3.7.7. generally similar to those of sprinklers.7.5. A diagram showing a typical system with component parts is given below.3.Handbook on Building Fire Codes The deluge system primarily caters for special hazards where intensive fires with a very fast rate of fire propagation are expected. While sprinkler system provides protection for buildings from internal fires.5.0 Page 115 . AUTOMATIC DRENCHER SYSTEMS 7. drencher systems(placed on roofs.5.
5.7. (b)Wall or curtain drenchers -. a fire brigade inlet should also be provided at the bottom. so that they provide a water curtain over the wall (c) Window drenchers -. Fig-39 A typical drencher system IITK-GSDMA-Fire 05-V3.These are used to protect window openings and placed on the top level of the windows so as to provide a water curtain over the windows.These operate in the form of a flat curtain over the wall openings or portions of a building most likely to be exposed to fire.5. The installation should normally be connected to the same supplies which cater to hydrant systems.5m is normally kept between the drencher heads 7. Besides.4. The maximum horizontal spacing of 2. and not more than 6 on the vertical feed pipe.7. 7.From the roof edge they throw a curtain of water upwards which then runs down the roof. Not more than 12 drenchers may be fixed on any horizontal line of pipe. The usual practice is to put a line of drenchers just below the eaves of the building.5.Handbook on Building Fire Codes (a) Roof drenchers .0 Page 116 .
5. A foam blanket over a liquid surface is capable of preventing vapour formation. pipework or hose for transportation. (ii) A foam system consists of an adequate water supply that can be pressurised.5. Fuel spills are quickly rendered safe by foam blanketing. air and fuel.8. & (c) High expansion foam systems.5. Foam extinguishing systems are of three types: (a) Low expansion foam systems. It is an essential extinguishing agent for aircraft as well as flammable liquid storage and handling areas.1. (a) General: (i) The general characteristics of foam as an extinguishing agent have already been dealt with under para 6. Three dimensional fires (of falling fuel) cannot be extinguished by foam unless the liquid has a high flash point. This may produce an increase in volume which may lead to slop over or boil over. (iv) It is widely accepted that foam is the only permanent extinguishing agent used for extinguishing fires in flammable / combustible liquids. foam forms an emulsion of steam.0 Page 117 . Foam Extinguishing Systems / Installations 7.8. a proportioning device. IITK-GSDMA-Fire 05-V3.2.2. (b) Medium expansion foam system. a supply of foam liquid concentrate. and foam applicators / pourers for distribution of foam over the risks. to be adhered to for foam to be effective: The burning liquid must be below its boiling point at NTP. Foam may also be applied as a protection against accumulation of toxic and flammable gases in hidden enclosures or cavities. (iii)There are certain criteria in general. The liquid must not be water-reactive. The liquid must not be unduly destructive to the foam. 7. At these temperatures. The fire must be a horizontal surface fire.8.Handbook on Building Fire Codes 7. Care must be taken in application of foam to liquids with a temperature higher than 100oC.
8. Generally. only AFFF type of foam concentrate is used for pre mixing purposes. 450 lpm and 900 lpm. The following methods are adopted for this: Self Induction (by using an inductor or pick-up tube). There is a modified version of inline variable inductor also for water flows of 225 lpm.5. (b) By induction of the concentrate into the water stream. Foam Concentrate Proportioning: (a) By pre-mixing the concentrate in water .5. with an additional knob for control of foam compound of induction ratio from 1% to 6%. foam generation process and foam distribution methods. Fig-40 A typical Inline Inductor IITK-GSDMA-Fire 05-V3. This method can be used for fixed or portable branch pipes and monitors.Handbook on Building Fire Codes 7.0 Page 118 . Foam Generation Methods: The foam production process assumes three separate operations foam concentration proportioning process. 7. The pressure drop across the inductor is usually about one third of the inlet pressure. Inline induction: Inline inductors are placed in the hose lines.3. usually at a distance of 25m to 50m from the branch.The shelf life of foam concentrate has a direct bearing on this method.4.8.
Handbook on Building Fire Codes Fig-41 Inline Variable Inductor with control knob for regulating foam concentrate induction rate By pass Induction: This method combines the best features of self induction and inline induction devices.0 Page 119 . It can also be built in permanently in the fire appliance. Fig-42 Diagrammatic lay out of Round-the-Pump Proportioner IITK-GSDMA-Fire 05-V3. Round-the-Pump Proportioner: This involves installation of the inductor in a by-pass line between the discharge and suction sides of the fire pump.
IITK-GSDMA-Fire 05-V3. Refinery Foam Tenders etc. AFFF should be used. Foams are not suitable for use on fires involving gases or liquefiable gases with BP below 0oC. Low expansion Fixed Foam Extinguishing Systems: in the case of Aviation CFTs. For gasoline and light crude oils. They are ineffective or dangerous to use on flammable liquids with temperatures in excess of 100oC. 7.8. below the surface so that they float to the surface under their own buoyancy (sub-surface application).Handbook on Building Fire Codes (c) Pressurised foam proportioning: (Displacement Proportioner) This arrangement is suitable for both large and small systems. Such systems often have water and foam concentrate stored as a premix solution in a tank which is pressurised by compressed air when operated or the foam concentrate can be stored and pressurised separately. (a) Low Expansion foam may be applied directly to the surface of the burning liquid (surface application) or may be applied in the case of tank fires. They should not be used on energised electrical equipment. (d) Specialised foam making systems.5. Refinery Foam Tenders etc.0 Page 120 . c) Limitations of Low Expansion Fixed Foam Systems: They are not suitable for extinction of running fuel fires.1.5. Their compatibility with dry chemical powders and certain wetting agents have to be verified before use. For these specially stabilised foam concentrates are used. Low expansion foams may also be applied by a semi sub-surface method. b) General The general requirements of a foam extinguishing system have already been explained in 7. they are not suitable for use on materials which react violently with water. Most Aqueous Film Forming Foams (AFFF) are not suitable for use on water-miscible flammable liquids. Self contained systems are those in which all components including water and foam concentrate are contained within the system. as in the case of Aviation CFTs. particularly where the liquids in the tanks are of considerable depth. or cryogenic liquids.5.8.
should be flushed thoroughly at the maximum practicable rate of flow.0 Page 121 . requirements. 2) Water supply mains. before connection is made to system piping. FP. Note: The selection may depend upon the available water pressure.Handbook on Building Fire Codes Only AFFF can be used in pre-mixed condition upto one year. Simultaneous use of water jets or sprays may adversly affect a foam blanket. The most suitable solution application rate. Most suitable proportioning method(s). Protein base foams are not suitable for this type of use. quality and pressure so that suitable pumps may be selected. (d) System Design (1) General: The following points should be taken note of: Full details of the flammable liquid its storage. System operation and any fire or gas detection equipment. Notes: 1) Provision should be made in the design for flushing with clean water after use of any lines. The most suitable foam making concentrate(P. Water supply. IITK-GSDMA-Fire 05-V3. Pipework sizes and pressure losses. Reserve foam concentrate supply. AFFF or FFFP as the case may be) in the appropriate concentration. Any special considerations such as the use of electrical equipment in areas where flammable vapours may be present. both underground and above ground. Most suitable equipment for making and delivering foam. quantity. System operating time. handling and location need to be known before any foam system is considered for installation. Quantity of foam concentrate required for extinction. Flushing Requirements.
fixed or semi-fixed. (ii) Portable.(a) Possible Advantages of Monitors and Foam Branches: (i) Foam can be projected under favourable circumstances. a manual override should also be provided. 5) All pipework should be subjected to a hydrostatic pressure test at 14 bars or 1. (iv) Mobile System: Includes foam producing units mounted on wheels (Self propelled fire tenders) or towed.8. (iii) Portable Systems: Includes portable foam producing equipment that can be carried manually and connected via fire hose to pressurised water / pre-mixed solution supply to produce foam jets / sprays.0 Page 122 . connected to the water supply (foam compound carrying units mounted on wheels have also to be included). for a period of 2hrs.7.5 times the maximum pressure anticipated. 7.Types of Foam Systems: (a) There are three basic types of systems and each may be used inside or outside buildings: (i) Installed. (b) Installed System (i) Fixed: This type has permanent steel pipework connected from the water supply via the fire water pump (if fitted) and foam liquid Foam can be projected under favourable circumstances.6. depending on the type and location of the risk. The pipework has provisions for water supply hoses to be connected (and sometimes foam proportioning device also).Handbook on Building Fire Codes 3) Foam system can be operated manually or automatically. 7.5.8. and (iii)Mobile. (ii) Semi-fixed: Has steel pipework from outside the bund wall (or similar location) upto the foam makers/pourers. 4) Where automatic operation method is adopted. IITK-GSDMA-Fire 05-V3. over considerable distances and to significant heights.5. whichever is greater. over proportioning device to the foam maker(s) which protect the hazard. The water supply is taken from hydrant system and the foam concentrate / solution is provided through mobile fire appliances.
5 (1) Fluoroprotein(FP) or Flurochemical(AFFF) Protein (P) (2) Hydrocarbon Hydrocarbon 6. (ii) Tanks having ruptured roofs with only limited access for foam are not easily extinguished by monitor application from ground level. and should be available for use in all parts of the complex to be protected. They may also be set up in the most favourable upwind position.Handbook on Building Fire Codes (ii) Portable and mobile monitor systems housed protected from weather. will be unaffected by explosion or flame exposure before fire fighting commences.) (3) 4 (4) 6. (b) Possible Limitations of Monitors and Branches: (i) Foam discharge may be affected by any wind and fire updraught resulting in discharge outside the affected area. are more likely to be kept in a serviceable condition. in oil jetty protection and fire tug use. (iii)Uniform foam distribution may not be achieved easily. for example. (iii)Oscillating monitors discharge foam evenly over very large areas. (c) Minimum Application Rates for Low Expansion Foams in Monitor or Foam Branchpipe Systems Foam Concentrate Flammable Liquid Minimum Application Rates(l/m2/min. (iv)Fixed automatically-operated monitors applying foam horizontally into a fire area may be obstructed by equipment positioned temporarily.0 Page 123 . thus rendering them suitable. automatically (iv)Fixed monitors may be remotely controlled from considerable distances.5 8 IITK-GSDMA-Fire 05-V3. (v) Portable foam branch pipes are not suitable for the primary protection of storage tanks of over 9m diameter and 6m height.
(f) The water draining from a foam can cool the flammable liquid slowly. heavy oil. 3. IITK-GSDMA-Fire 05-V3. For tanks containing foam destructive liquids this method of application may not be suitable. Kerosene 15 60 Tanks containing liquid hydrocarbons (e) Care should be taken when applying foam to high viscosity liquids such as burning asphalt.Handbook on Building Fire Codes Notes 1. For tanks containing volatile fuels with flash point below 40oC it may be necessary to increase this rate of application 2. there is a considerable risk that the drained water will boil within the hot oil.for example. but if the drainage is too rapid.0 Page 124 . Allowance should be made for loss due to wind or fire up-draught when extinguishing storage tank fires. greater than 40oC. for example: gasoline. Mobile/Portable monitors and foam branch pipes All Fuel Flash Point Minimum Discharge Time(Min. (d) Minimum Discharge Times for Low Expansion Foams in Monitor or Foam Branchpipe Systems: Risk Equipment Type (2) Fixed monitors fixed foam branchpipes.) (4) 10 (1) Indoor and Outdoor spills (3) All All Less than 40oC. etc. when heated to 100oC and above. thus producing dangerous frothing and even slop-over of the tank contents.
Tanks containing liquids with flash points above 60oC do not normally need to be protected by fixed foam systems unless these liquids are heated to their flash points. 7.Handbook on Building Fire Codes (g) While low expansion foam is not considered an effective agent for extinguishing three dimensional running flammable liquid fires. These systems are intended for use in tank farms. (c) Foam Chamber (Vapour Seal Box) Incorporates equipment designed to prevent tank vapour enter ing the foam pipework systems. FIXED FOAM POURER SYSTEMS (SURFACE OR TOP APPLICATION) FOR FIXED ROOF TANKS (a) General This covers the systems which are designed to apply foam through pouring devices. and thus promote foam distribution. oil refineries and chemical plants.8. (b) Fixed Foam Pourer (Foam Discharge Outlet) Equipment is designed to discharge foam onto the top portion internal wall of a tank. it can control the pool fire beneath the running fire. and to provide primary protection for outdoor atmospheric flammable and combustible liquids in fixed roof tanks including covered floating roof tanks. IITK-GSDMA-Fire 05-V3. (h) With some flammable liquids the water spray distributed by foam sprayers can provide effective fire control as in high flash point hydrocarbon.8. so that it will flow down gently onto the surface of the flammable liquid without undue submergence of the foam or agitation of the surface.5. while allowing the foam to enter the tank without undue resistance when required. leaving control of the running fire to other means like dry powder fire extinguishers. and are usually operated manually. Some pourers are designed to discharge the foam tangentially in order to create a circular motion.0 Page 125 .
methyl methacrylate monomer and mixtures of watermiscible liquids in general may require higher application rates. (e) Minimum Application Rates for Low Expansion Foam Systems Using Fixed Foam Pourers Foam Concentrate Flammable Liquid Minimum Application Rate (l/m2/min. methyl isobutyl ketone.Handbook on Building Fire Codes Fig-43 Foam chamber and pourer with vapour shield (d) It has to be borne in mind that there is a risk of the pourers getting damaged due to explosion or fire exposure.) 8 1pm All types (1) NOTES Hydrocarbon 1. Protection of products such as amines and anhydrides which are particularly foam destructive require special consideration. Products such as isopropyl alcohol. When foams are used on volatile fuels with flash points below 40oC the above rates may have to be increased 2.0 Page 126 . butyl alcohol. IITK-GSDMA-Fire 05-V3.
Handbook on Building Fire Codes 3. Flash point above 40oC Kerosene etc. located to give even foam distribution. 55 30 45 30 10 Flouroprotein (FP) Flourochemical (AFFF) (Minute) 10 (g) Minimum Number of Foam Pourers for Flammable Liquid Storage Tanks (Fixed Roof) Tank Diameter(m) Up to 24 Over 24 to 36 Over 36 to 42 Over 42 to 48 Over 48 to 54 Over 54 to 60 Minimum Number of Foam Poureres 1 2 3 4 5 6 (h) For tanks over 60 m in diameter. IITK-GSDMA-Fire 05-V3. It is often necessary to use special designs of pourer giving very gentle foam application. in order to extinguish 'alcohol' type fires. Central sub-surface application may be used to give protection to the central area of the fuel surface. at least one additional foam pourer should be added for each additional 460m2 of flammable liquid surface. (f) Minimum Discharge Times for Low Expansion Foam Systems Using Fixed Foam Pourers Risk Minimum Discharge Time Protein (P) (Minute) Indoor and outdoor spill protection Tanks containing liquid hydrocarbons: Flash point below 40oC Gasoline etc.0 Page 127 .
Handbook on Building Fire Codes (i) Fixed foam pourers should be equipped with an effective and durable seal. Where foam is injected into the rim seal area. (iv) Possible limitations Where foam is injected below the pantograph or weather shield a foam generator might not be capable of operating against the pressure required to force foam around the rim seal area.9. or behind the metal weather shield into the rim seal area in the case of tube seal designs. it need only be for the rim seal area. and has to be protected or designed to withstand the effects of a rim seal fire. But if fixed protection is pecified. (ii) Floating roof seals may be of the pantograph type or may be a tube seal with metal weather shield. FIXED FOAM POURERS FOR OPEN TOP FLOATING ROOF TANKS (a) General (i) This covers fixed foam pourers for the primary protection of open top floating roof tanks. or should be injected below the pantograph seal. Foam is applied gently without severe mixing with the fuel. IITK-GSDMA-Fire 05-V3. (iii) Possible Advantages Total foam output reaches the rim seal area. Adverse winds and obstructions projecting through the fuel surface may reduce the effectiveness of the system and allowance should be made in the rate of application of foam.5. Foam should be discharged into the seal area behind a foam dam secured to the floating roof. Note: Portable foam branches are also suitable for extinguishing rim fires in floating roof tanks.8. special pipework is needed to conduct foam from outside the shell onto the roof area. Using foam pourers and a foam dam. Access should be provided to permit inspection and maintenance. This needs to be hinged or jointed to allow for movement of the roof.0 Page 128 . the equipment is simple and requires only moderate maintenance. frangible under low pressure to prevent entry of vapour into the foam pourer and pipe lines. Tanks of this design have a good fire record and normally do not require fixed protection. including replacement of the vapour seals. 7.
by which foam is injected at the base of the tank with sufficient pressure to overcome the head of fuel.8. IITK-GSDMA-Fire 05-V3. the dam should be installed on top of the roof adjacent to the weather shield.5 1/m2/minute based on the area of the annular ring between the foam dam and tank shell.Handbook on Building Fire Codes (b) Systems involving the use of a Foam Dam: Foam Dams should be fitted where foam is discharged above the seal area.10. Systems should be designed to deliver not less than 12. They should also be fitted for systems where foam is injected below the weather shield of a tube seal design. (c) Where foam dams are not provided. the system should be designed to deliver not less than 20 lpm/m2 of foam. Fig-44 Foam system installed on the floating roof top 7. A special foam inlet pipe may be used. if the distance between the top of the tube seal and the top of the roof is less than 150mm. SUB SURFACE FOAM SYSTEMS (a) General (i) This covers systems for the protection of fuel storage tanks.5.0 Page 129 . In such cases. The system should be capable of operation for at least 20 mins.
is less likely to be damaged by fire or explosion. (v) The circulation of cold fuel from the base of the tank to the burning surface caused by the rising foam stream can be utilised to assist extinction and to dissipate hot fuel layers at the burning surface. (iii)Sub-surface application is not suitable for the protection of water-miscible fuels and only fluoroprotein and AFFF type foam concentrates are suitable for this purpose. Intermittent application of the foam can induce circulation of the fuel in the tank. (ii) Sub-surface systems are not suitable for the protection of floating roof tanks because the roof will prevent complete foam distribution. where there has been a long preburn prior to the application of foam. (c) Number of Foam Injection Points for Low Expansion Foams in Sub-surface Systems Tank diameter (m) Up to 24 Over 24 to 36 Over 36 to 42 Over 42 to 48 Over 48 to 54 Over 54 to 60 above 60 m add one extra inlet for each additional ara of Volatile Products (Flash point below 40oC) 1 2 3 4 5 6 460m2 Non-volatile Products Flash point above 40oC) 1 1 2 2 2 3 700m2 IITK-GSDMA-Fire 05-V3. being at ground level.0 Page 130 . (b) Possible Limitations (i) Sub-Surface systems are not suitable for water-miscible fuels.Handbook on Building Fire Codes (ii) This type of protection is suitable for fixed roof tanks. In order to avoid frothing and slop-over. (iii)With some fuels. continuous application of foam should be avoided in the initial stages. a hot zone may exist near the burning surface at temperature in excess of 100oC. thereby bringing the cooler layers of fuel to the surface. (iv)The system is essentially simple and. The foam injected intermittently will disperse without sufficient steam formation to produce frothing. but it is not suitable for floating roof tanks with or without fixed roofs.
Fig-45 Layout of semi subsurface foam system IITK-GSDMA-Fire 05-V3.8. A special container within the tank houses the hose and is connected at the base of the tank to an external foam generator capable of working against the maximum product head.5. fluoroprotein or AFFF concentrates may be used. SEMI SUB-SURFACE SYSTEMS (a) General (i) This covers systems from which foam is applied to the surface of oil storage tanks via a flexible hose rising from the base of the tank. (iii)Protein. because the roof will prevent distribution. the semi sub-surface units can be arranged to produce an even distribution over the fuel surface. This type of protection is suitable for fixed roof tanks but is not normally considered appropriate for floating roof tanks with or without fixed roofs. (iv)Semi sub-surface systems may not be suitable for the protection of floating roof tanks. (ii) With large tanks.0 Page 131 .11.Handbook on Building Fire Codes 7.
5. Diameter of LargestTank (in m) Mini.13.Handbook on Building Fire Codes 7. and the supplementary protection specified supplementary hydrants should be provided for use with portable foam monitors or portable foam towers in the event that a fixed discharge outlet on the primary protection system is damaged.12.5. Discharge Time (minute) Up to 10 Over 10 and up 20 Over 20 and up 30 Over 30 and up 40 Over 40 1 1 2 2 3 10 20 20 30 30 (c) Hydrants For fixed piping systems in addition to the primary means of protection. Additional foam concentrate should be provided to permit operation of all extra branchpipes simultaneously with the primary means of fire protection and for the minimum discharge duration specified in Table below. These areas should be considered as spill fires. 7.8.8. In lieu of a foam hydrant a water hydrant may be used in conjunction with suitable foam producing equipment. Each hydrant should be located between 15m and 75 m from the shells of the tanks being protected by the associated primary system. Number of Foam Branchpipes with Manifold with each Hydrant Min. The flow from hydrants should be sufficient to support portable equipment to be used. SUPPLEMENTARY PROTECTION FOR STORAGE TANKS (a) Each foam branchpipe should be designed to give a solution flow rate of at least 500 1/min.0 Page 132 . BUND PROTECTION SYSTEM (a) This covers systems which apply foam to the bund area around tanks. IITK-GSDMA-Fire 05-V3. (b) Minimum Number of Supplementary Branchpipes and Duration of Discharge.
Fig-46 A typical medium expansion foam generator IITK-GSDMA-Fire 05-V3. Local application. MEDIUM AND HIGH EXPANSION FOAM SYSTEM (a) System design and use: (i) This type of foam is an aggregation of bubbles resulting from mechanical expansion of a foam solution by air or by other gases.8.14.5.Handbook on Building Fire Codes 7. (iii)Medium expansion foam generators are of the 'aspirator' type and are mostly used for local and portable type applications. and Portable. with expansion ratios in the range of 50:1 to 1000:1 (ii) There are 3 type of systems: Total flooding.0 Page 133 .
large masses of bubbles or foam are formed. In this the foam solution is discharged onto a screen through which air is blown by a fan or a blower. basements.Handbook on Building Fire Codes (iv)The 'blower' type generator is normally designed for production of high expansion foam. mines. (vi)High expansion foam may be used in controlling LNG fires and unignited spills by forming an ice layer on the liquid and by helping to disperse the vapour cloud. Fig-47 Principles of operation of a high expansion foam generator (v) Basically. Windows and doors in such premises should IITK-GSDMA-Fire 05-V3. medium and high expansion foam systems are used to control or extinguish surface fires in flammable and combustible liquids and solids. compressed air or gas. ship's holds. an electric motor. and deep-seated fires involving solid smouldering materials. (viii) It is important that leakage of the foam from the enclosures protected is avoided. As the air passes through the screen which is wetted with foam solution. or an internal combustion engine. cable tunnels. high-rack storages etc. (vii) Total flooding system may be used in enclosures surrounding the hazard to be protected like walls. The blower may be powered by a hydraulic or water motor.0 Page 134 .
Personnel entering the space should wear BA sets. the minimum 50 % drainage time should be approximately 8 min. and carry a life line with them.0 Page 135 .(1 litre of foam concentrate can produce approx 50m3 of high expansion foam) (x) The submergence time should be approx.Handbook on Building Fire Codes be designed to close automatically. 2 to 3 min. entering the foam filled space should be avoided unless adequate precautions are taken.6m (2 feet). Polyethylene tubes which are used for conveyance of discharge of foam should be correctly designed for efficient projection of the foam. since loss of vision and disorientation may be experienced by the persons involved. the minimum depth above the hazard should be about 0. (xi)After extinguishment. Fig-48 Typical High Expansion Foam System for Warehouse- IITK-GSDMA-Fire 05-V3. with provisions for high level venting of the air in the enclosure which is displaced by the foam. A coarse water spray may be used for clearing the foam. For high expansion foam system. (ix)Generally.
9.5.1. Fires involving combustible gases. (ii) Low Pressure System: In this system the gas is stored in a refrigerated tank at a _ temperature of 18oC and at 20 bars pressure. and on operation of the installation. and their halides. the gas is discharged into the protected space with considerable noise. The tank is connected by pipework to the protected spaces with discharge nozzles sited at strategic points on the pipework. magnesium.0 Page 136 . General (i) CO2 is suitable for extinguishing the undermentioned types of fires: Fires involving smouldering carbonaceous solid materials (Class A fires). and feeding into a high pressure distribution pipework. CO2 EXTINGUISHING SYSTEMS / INSTALLATIONS 7.5. There are two types of CO2 extinguishing systems: (i) High Pressure System: This installation consists of a battery of one or more cylinders of CO2 interconnected by a manifold. except where explosive atmospheres are likely to develop (Class C fires).2. potassium. such as cellulose nitrate. Special discharge nozzles are fitted in the pipework.9. titanium and zirconium. (ii) CO2 is not suitable for fires involving the following: Chemicals containing their own supply of oxygen. 7. and Fires involving live electrical apparatus and installations.. IITK-GSDMA-Fire 05-V3. Reactive metals such as sodium. Fires involving flammable and combustible liquids (Clas B fires).5. chlorates etc.Handbook on Building Fire Codes 7.9.
The minimum concentration used in the total flooding system is 34% CO2 by volume for surface-burning materials. Methods of Application: There are two basic methods of applying CO 2 in the fire extinguishing systems: (i) Total Flooding: In these systems the CO2 is applied through nozzles to develop a uniform concentration of CO 2 in the protected enclosure.5. 50% concentration will be required for electrical machines. and for storage vaults and dust collectors 75%. Fig-50 CO 2 Total Flooding System protecting turbo generator IITK-GSDMA-Fire 05-V3.3.Handbook on Building Fire Codes Fig-49 Low pressure CO 2 Storage Unit 7.0 Page 137 .bulk paper requires 65%.9.
11. Multijet discharge horn 12. 3. 9. The discharge should be continued for a minimum of 30 sec. 5.Handbook on Building Fire Codes Fig-51 A CO 2 Extinguishing System that has been activated (ii) Local Application: In this system CO2 is discharged directly on the fires through specially designed nozzles. where it is difficult to prevent leakage until rotation stops. or longer.( In some cases. Heat actuated detector 13. 6. CO 2 Cylinder System Controller Pressure Connector Cylinder actuator Manual release cable in protective conduit Detection airtube in protective conduit CO2 feed pipe Manual release unit Pressure trip Pressure switch 10. Extended discharge is particularly applicable to enclosed rotating electrical equipment like generators. Flanged multijet horn 14. 7.0 Page 138 . if required 1. Fan multijet horn Fig-52 CO 2 Local Application System protecting quench tank (iii) Extended Discharge: This method is used when the risk enclosure is not tight to retain the extinguishing concentration. the time delay for stoppage of rotating machinery was up to 30 mins. 4.) IITK-GSDMA-Fire 05-V3. 2. 8.
0 Page 139 .Handbook on Building Fire Codes IITK-GSDMA-Fire 05-V3.
ducts.0 Page 140 . gases and solids(most suitable for total flooding systems).4. and remain shut. Particular risks.9. and is adopted to supplement fixed system or portable equipment 7.5. Chances of fire occurring in more than one space at the same time. Likelihood of spread of fire from one compartment to another. (iii)Where openings cannot be shut. (ii) Openings and ventilation systems should be closed or shut down automatically with the activation of the discharge. Temperature of protected area. ovens etc. IITK-GSDMA-Fire 05-V3. additional CO2 quantities should be provided. (iv)CO 2 total flooding systems can be successfully used for protection of vaults. (c) Types of fires which can be extinguished by CO2 total flooding system are: (i) Surface fires involving in flammable liquids. Openings that cannot be closed. Material to be protected. The extinguishing concentration should be maintained for a sufficient period so that re-ignition can be prevented. System Design: (a) Total Flooding System: (i) The enclosure construction shall be such as to prevent leakage of gas. enclosed machines.Handbook on Building Fire Codes (iv) Hand Hose Lines: This can be used for total flooding or local application. and their contents (b) Design Quantity: This should be determined on factors like: Room size. and (ii) Deep-seated fires involving in smouldering materials. Ventilation systems which cannot be shut down.
For deep-seated fires. (i) For enclosed rotating electrical equipment. the design concentration should be achieved within 7 min. (g) Additional qualities of CO2 should be provided to compensate for any special conditions. (n) Duration of Discharge: The minimum effective discharge time should be 30 sec.Handbook on Building Fire Codes (d) The system should be designed taking into account the atmospheric correction factor.0 Page 141 . the concentration should be maintained for not less than 20 min. the design concentration should be achieved within one minute. IITK-GSDMA-Fire 05-V3. (l) The quantity of CO2 required for local application systems should be based on the total rate of discharge needed to blanket the area. the quantity of CO2 should be increased by 40%. a minimum concentration of 30% should be maintained for not less than 20 min. and maintenance of the discharge to ensure complete extinguishment. (k) The hazard protected should be isolated so that fire will not spread outside. and the maximum time to achieve the design concentration is as follows: For surface fires. (e) The theoretical minimum CO2 concentration for extinguishment of surface fires of some common liquids and gases are shown in the Table overleaf: (f) The requirements of CO2 for deep seated fires is based on tight enclosures. which may be increased to compensate for any hazard condition. (o) The system should have sufficient number of nozzles to cover the entire area protected. _ (j) High pressure storage temperatures can range from 18OC to O 54 C. The entire hazard should be protected.. (h) Rate of application: The minimum design rate of application should be based on the quantity of CO2. since only the liquid portion of the discharge is effective. After reaching the design point. (m) For systems with high pressure storage. .
Safety inter-lock. such as reduced visibility and suffocation. Switch off ventilation system. Inhitbit switch and time delay. The minimum safety precautions for the system are. the automatic release of the system should be isolated. (c) Since discharge of liquid CO2 can produce electrostatic charges. Automatic control. (q) The system should have indicating and alarm devices as given below: Automatic visual warning with coloured indicator lights to indicate: Manual control.5. and the lock-off control activated. IITK-GSDMA-Fire 05-V3.0 Page 142 .Handbook on Building Fire Codes (p) The system should generally be designed for automatic operation. CO2 systems installed in explosive areas should be provided with metal nozzles which should be properly bonded and earthed. CO2 discharged.9. with manual override. and lock-off valve. (r) Other automatic devices designed to be installed are to: Operate door closing devices. Suitable safeguards should be provided to ensure prompt evacuation and to prevent entry into such areas.5 Safety Requirements: (a) The CO2 discharge can create serious hazards for personnel. (b) Before entry into protected spaces. (d) Adequate lighting with directional signs should be provided to ensure quick occupant evacuation. Close openings in ventilating ducts. (e) The audible and visual alarms should activate a few minutes before the operation of CO2 installation. 7. Operate fire screens.
5. In addition.10. Acceptance Tests: The completed CO2 system should be subjected to the following tests before acceptance: (a) Full Discharge Test. of dry chemical powder as an extinguishing agent have already been covered under para 6. However.25 times the calculated pipework's maximum developed storage pressure at 55oC. it has negligible toxic effects.5.Handbook on Building Fire Codes (f) Warning and instructional signs should be positioned at the entrance to the protected area.0 Page 143 .10. Dry chemical is a highly effective extinguishing agent possessing the unique property of quick knocking down of fires. 7.1. General (a) The characteristics etc.6.7. the following procedure should be followed: (i) Subject the distribution system to a hydrostatic pressure test of 1. on discharge of dry chemical powder system. IITK-GSDMA-Fire 05-V3. (g) Premises protected with Co2 installation should display a distinctive symbol (as shown below) as a warning of the presence of CO2 .5. (ii) Subject the protected area to an enclosure integrity test. (b) Where a full discharge test is considered not necessary by the competent authority. as per standards. Dry Chemical Extinguishing Systems / Installations: 7. there will be visibility problems as well as the need for lot of cleaningup after use. followed by purging the system. Fig-53 Standard warning symbol of a CO 2 Installation 7.9.
Smothering.510. cooling and radiation shielding contribute to the extinguishing efficiency of dry chemical.0 Page 144 . 7. Methods of Application: The two basic types of dry chemical systems are fixed systems and hand hose line systems. (d) The systems are used primarily for flammable liquid fire hazards such as dip tanks. However. (h) Although dry chemical can knock down fires quickly. (f) Regular dry chemical will not extinguish fires that penetrate beneath the surfaces. the flame is immediately put out (knocking down effect).3. (c) Due to its quick extinguishing ability it is useful for surface fires involving ordinary combustible materials. research has proved that its power of chain breaking reaction (inhibition of free radicals) in the flame is the principal cause of extinguishment. Therefore.5. following the dry chemical application. Uses and Limitations of Dry Chemical System: (a) Dry Chemical is primarily used to extinguish flammable liquid fires. like water or foam has to be applied on the fire for achieving permanent extinguishment. it can also be used on flammable liquid fires involving live electrical equipment. (e) They are not recommended for use on delicate electrical equipment such as telephone switch boards and electronic computers since such equipment are liable to damage by dry chemical deposit. (g) They will not extinguish fires that supply their own oxygen by combustion. (b) Being electrically non-conductive. IITK-GSDMA-Fire 05-V3. 7.Handbook on Building Fire Codes (b) When applied on fire. another permanent extinguishing agent. the extinguishing effect is not permanent. Portable extinguishers constitute another method of application of dry chemical. flammable liquid storage rooms and flammable liquid spill areas.2.10.
(c) On the other hand. Pre-determined systems are frequently used for kitchen ranges and hoods. Care has to be exercised to ensure that only alkaline dry chemicals(sod. 7. fixed piping and nozzles through which the dry chemical can be discharged into the hazard area. IITK-GSDMA-Fire 05-V3. are pre-determined by fire tests. Fixed dry chemical systems are of two types: total flooding and local application. diesel and gas turbine locomotives. piping / hose to carry agent to the fire areas. pipe sizes. (ii) In local application system. The hose stations are connected to the agent container directly or through piping. Only where no re-ignition is anticipated can total flooding be resorted to. bi-carbonate etc. bi-carbonate. an expellant gas. These systems are quite useful for protection of gasoline loading racks. an actuating mechanism. The principal use of the local application systems is to protect open tanks of flammable liquids. and ABC or multi purpose dry chemical (mono ammonium phosphate) should never be used. re-ignition possibilities have to be considered.4.5. pot. nozzles to discharge the agent into the area and automatic and / or manual actuating devices. System Design: (a) Usually.Handbook on Building Fire Codes (a) Fixed Systems: These consist of a supply of dry chemical. number of fittings. or when all openings can be closed automatically. dry chemical system consists of dry chemical and expellant gas storage tanks.0 Page 145 . Here again. (iii) Hand hose line systems consist of a supply of dry chemical and expellant gas with one or more hand hose lines to apply the dry chemical on to the fire.) are used in these cases. and aircraft hangars.10. the nuzzles are arranged to discharge directly into the fire. (i) Total flooding: In total flooding systems. a pre determined amount of dry chemical is discharged through fixed piping and nozzles into the protected area. flammable liquid storage areas. number and types of nozzles etc. Total flooding is applicable only when the risk is totally enclosed. (b) An engineered system needs individual calculations and designs to determine the various factors necessary for the system. the quantity of dry chemicals. including deep fat fryers. in a pre-engineered system (also called as a package system).
(i) The efficacy of the system. Reserve Supply: A fully charged reserve unit permanently connected to the system will be desirable as reserve supply for the system so that immediate re-commissioning of the system will be possible. fittings and nozzles. suitable directional valves and controls will have to be incorporated into the system so as to enable the system operation to be directed to the particular area affected by fire. (k) In case one system is designed to cater for 2 or 3 hazard areas. (g) Suitable safety alarms should be sounded before actuation of the systems. manual controls should also be provided as an alternative. it should be discarded. Once the powder loses its free flowing characteristics. But for smaller systems. (j) Quantities of dry chemicals and rates of flow for the systems should also be carefully calculated. 7.5.0 Page 146 .5. to a large extent. depends on the proper design and construction of the pipings. (h) Generally. controlled discharge type of nozzles are preferred for the system. Fig-54 Dry Chemical Extinguising System (for protection of cooking range) IITK-GSDMA-Fire 05-V3. dry air or CO2 can be used.10.Handbook on Building Fire Codes (d) Expellant gas used for dry chemical systems is normally dry Nitrogen. (e) Extreme care has to be taken to ensure moisture-free storage for dry chemical as well as for expellant gas. (f) For automatic operation systems.
10. (iii)The amount of expellant gas should also be checked every months.0 Page 147 . 7 . 5 . This unique combination of highly desirable properties led to these agents being selected for a wide range of fire protection applications. should also be inspected for trouble free operatlion. but imparts flame extinguishment properties also. H A L O N F I R E E X T I N G U I S H I N G S Y S T E M S / INSTALLATIONS 7. and leave no residue (coming under the category of clean agents). (vii) Care has to be exercised by periodical inspections to ensure that the dry chemical powder inside the containers always remains dry. (ii) The quantity of dry chemical should be checked every six month. thermostats etc. (iv)Inadvertant mixing of different base dry chemicals can initiate dangerous reactions. electrically non-conductive. chlorine or iodine. which posessed exceptional effectiveness in fire extinguishing and explosion prevention and suppression.Handbook on Building Fire Codes 7. 11 . like detectors. all piping and nozzles in the system should be blown clear. fusible links.6. IITK-GSDMA-Fire 05-V3.1.5. after discharge. This combination with halogens not only renders these agents nonflammable.5. (b) Halons were first introduced into commercial use during the 1960s. Halons are used both in portable fire extinguishers and in extinguishing systems. (vi)System actuating devices. (viii) Every time.11. These agents are clean. (v) Nozzles should be examined to see that they are free of obstructions and in good operation condition. bromine. General (a) Halons(Halogenated Extinguishing Agents) are hydrocarbons in which one or more hydrogen atoms have been replaced by halogen atoms: fluorine. Inspection and Test Procedures: (i) Routine inspection system should be carried out every month. Maintenance. generating CO2 gas and double de-composition products which may result in equipment failure or loss of discharge capability.
The ODP for Halon 1211 was found to be 3 times more than CFC. the specification standards concerning these fire fighting agents and their systems still continue to be relevant. industrial. including halons. The ODP for Halon 1301 has been found to be 13 times more than CFC (Chloro Flouro Carbon) whose ODP was reckoned as 1. Halon extinguishing systems continue to be used for critical IITK-GSDMA-Fire 05-V3. a vapourising liquid at room temperatures. it was found that the Ozone Depletion Potential(ODP) of the halons was much higher than other substances involved.Dibromotetrafluoroethane Chemical formula . commercial.0 Page 148 .C2F4Br2. (ii) Halon 1211 . marine. has been used widely in fixed systems throughout the industrial. were responsible for catalytic depletion of the stratospheric ozone layer. which is a gas at room temperature. Halon 1211. defence and aviation industries. and (iii)Halon 2402 . and will be phased out in the developing countries also by the year 2010. Halon 2402. has primarily been used in the defence.CF2BrCl. a low boiling liquid. and to a limited extent in extinguishing systems for unoccupied areas. However. therefore. it was revealed that certain substances. production of the Halons ceased in the developing countries by 1 January 1994. was preferred for use in portable fire extinguishers. marine and aviation sectors in Russia and other former Soviet Union countries. (d) Halon 1301. (g) Many Halon systems still remain in use throughout the world and.Handbook on Building Fire Codes (c) Halons which are commonly used as fire extinguishing agents are: (i) Halon 1301 . In fact. (e) In the early 80s.CF3Br.Bromochlorodifluoromethane Chemical formula . the development as well as utilisation of Halon alternative agents are currently in progress worldwide. as a result of research studies. and to a limited extent in Indian Navy.Bromotrifluoromethane Chemical formula . Apart from the Halon extinguishing systems which are in existence currently. (f) On account of the coming into force of the international agreement known as Montreal Protocol on substances having ODP.
Handbook on Building Fire Codes
applications. Recycled Halons, recovered from less critical applications, are now providing the source of supply for specialised applications such as defence equipment, aviation use and explosion prevention / suppression applications that remain dependent on Halons. 188.8.131.52. (a) Halon extinguishing agents achieve flame extinguishment primarily by inhibiting flame chain reactions (a process known as chain breaking). Among the Halogens, bromine is much more effective in this process than chlorine or fluorine. In total flooding systems, the effectiveness of the Halons on flammable liquids and vapour fires is quite phenomenal. Rapid and complete extinguishment is obtained with low concentrations of agent. A comparative statement of flame extinguishment values for Halon 1301 and Halon 1211 are shown below: Average Percent by Volume of Agent in Air Required for Flame Extinguishment Fuel Methane Propane n-Heptane Ethylene Benzene Ethanol Acetone Halon 1301 3.1 4.3 4.1 6.8 3.3 3.8 3.3 Halon 1211 3.5 4.8 4.1 7.2 2.9 4.2 3.6
(b) Toxicity: As per research studies conducted in the US, the approx. lethal concentration (ALC) for 15 min. exposures to Halon 1301, Halon 1211 and Halon 2402 have been found to be 83%, 32% and 13% by volume respectively. Experience and testing have shown that personnel may be exposed to Halon 1301 in low concentrations for brief periods without serious risk. However, on application on fires(of temperatures approx. above 482oC), Halons usually produce decomposition products like hydrogen fluoride (HF), hydrogen bromide(HBr), bromine(Br) etc., which can prove lethal.
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126.96.36.199. Total flooding systems: (a) Halon 1301 total flooding systems are usually installed for protection of computer rooms, electrical switchgear rooms, magnetic tape storage walls, electronic control rooms, storage areas for high value stores, books etc., machinery spaces in ships, cargo areas in aircraft, processing and storage areas for highly flammable liquids etc. Halon 1301, by virtue of its lower toxicity, higher volatality and better fire extinguishing efficiency, offers particular advantage for use in total flooding systems. (b) Halon 1301 total flooding systems should not be used in concentrations greater than 10% in normally occupied areas. (c) Minimum design concentrations of Halon 1301 for flame extinguishment for a few fuels are shown below: Fuel Acetone Benzene Ethanol Ethylene Methane n-Heptane Propane Minimum Design Concentration % by Volume 5.0 5.0 5.0 8.2 5.0 5.0 5.2
(d) Halon 1301 design concentrations required for inerting purposes is slightly higher than the design concentrations for extinguishment, as is the case with other extinguishing agents also. The design concentration required for inerting certain fuels are shown below: Fuel Acetone Benzene Ethanol Ethylene Hydrogen Methane n-Heptane Propane Minimum Conc.% by Volume* 7.5 5.0 11.1 13.2 31.4 7.7 6.9 6.7
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22.214.171.124. Local Application Systems: Local application systems are meant for protection of hazards which have no fixed enclosure around them. Individual hazards within confined spaces may be protected by this method. In this method, the discharge nozzle is directed at the surface or on the object to be protected. Hence, the design of the nozzle has an important role to play in this system. The discharge velocity and rate must be suitable to penetrate the flame and produce extinguishment. 126.96.36.199. Specialised Systems: These are widely used to protect aircraft engine nacelles, racing cars, military vehicles, emergency generator motors etc. The important characteristic of a specialised system is that it can be applied only to the specific hazard for which it was designed and tested. 18.104.22.168. Maintenance of Halon Extinguishing Systems: (a) Since the age of most of the existing Halon extinguishing systems may range anything from 10 to 20 years or more, it is essential, in the interests of operational efficiency of the systems, and safety of personnel concerned, that stringent inspection and maintenance schedules for these systems are formulated and implemented. (b) Some of the features to be borne in mind in this regard are as follows: The system should be visually inspected for evidence of corossion or other damage, at least every six months; The storage containers must be checked for loss of agent as well as loss of pressurising gas by suitable methods, at least every six months. Liquid level indicators, if available, are to be preferred for checking the quantity of agent, rather than weighing, which is more cumbersome and time-consuming; At least annually, the operational characteristics of the systems should be re-tested by knowledgeable and qualified persons; It should be ensured that inadvertent Halon release does not occur due to fault in service or maintenance procedures; Enclosure integrity tests should be carried out at least once a year.
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(c) Recycling of Halons: (i) It is quite likely that in the existing Halon extinguishing systems, either the agent quantity must have been reduced, or the agent quality must have been adversely affected. Recycling of Halons is important to avoid atmospheric release, as well as to cater to the need for protection of essential applications. (ii) Halon cylinders and valves contain a liquified compressed gas. Further, the Halon cylinder valves are designed to accommodate the high flow rates required for fulfilling the discharge time of less than 10 sec. Consequently, Halon cylinders have the potential to cause serious damage, injury, or death. Before a Halon cylinder is removed from the system retaining brackets, the cylinder valve must be made safe and anti-recoil device placed in the discharge opening. Several incidents of damage, injury and fatality have occurred from failure to take these precautions (as per documented evidence). (iii)It is important that whenever any users contemplate decommissioning of any Halon extinguishing system due to age of the system or for other reasons, the manufacturer of the equipments as well as the installer besides any other designated authority should be contacted for necessary technical advice and assistance.
(1) Spherical Halon container (2) Wall bracket (3) Discharge nozzle (4) Control Unit (5) Halon containers (6) Electrical connector (7) Smoke detectors 8) Detector 'operated' lamp 9) Break Glass manual release (10) Remote indiacation box (11) Pressure Switch (12) Direction valve (13) System actuator (14) Pneumatic heat detector (15) Control head (16) Release head.
Fig-55 Halon Total Flooding System for oil-filled switchgear & transformers
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(1) Spherical Halon container (2) Wall bracket (3) Discharge nozzle (4) Control Unit (5) Halon containers (6) Electrical connector (7) Smoke detectors 8) Detector 'operated' lamp 9) Break Glass manual release (10) Remote indiacation box (11) Pressure Switch (12) Direction valve (13) System actuator (14) Pneumatic heat detector (15) Control head (16) Release head.
Fig-56 Halon Modular Total Flooding System protecting electronic data processing equipment and tape storage rooms
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IITK-GSDMA-Fire 05-V3. Clean agent Halon replacements fall into two broad categories: (i) Halocarbon agents: These are compounds containing carbon. Are liquefied gases. All use nitrogen super pressurisation for discharge purposes(except HFC 23). Perfluorocarbons(FC or PFC). and Fluoroiodocarbons(FIC) Their common characteristics are: Electrical non-conductivity. bromine. General (a) The phase-out of Halon production had dramatic impact on the fire and explosion protection industry. Since Halons occupied an important place in fire protection.5. their replacement for various applications has been posing several challenges and problems for the fire protection communities all over the world.5. Can be stored and discharged from typical Halon 1301 hardware(except HFC 23). HALON ALTERNATIVE EXTINGUISHING SYSTEMS / INSTALLATIONS 7.0 Page 154 . fluorine and iodine.12. chlorine. Hydrofluorocarbons(HFC). hydrogen.Handbook on Building Fire Codes 7. Are clean agents which vapourise readily leaving no residue. The process of developing and application of Halon alternatives has been making rapid progress during the past few years (b) Clean fire suppression agents are fire extinguishants that vapourise readily and leave no residue. Hydrochloroflurocarbons(HCFC). They are grouped into five categories: Hydrobromofluorocarbons(HBFC). All produce more decomposition products (mainly HF) than Halon 1301. in terms of storage volume and agent weight.1. All are total flooding gases after discharge.12. All are more expensive than 1301 on weight basis. All are less efficient fire extinguishants than Halon 1301.
Handbook on Building Fire Codes (ii) Inert Gases and Mixtures: These include the following: (i) Inergen . the relative efficiency in breaking Halogen species bonds.12. (a)Table-1 showing the New Technology Halon Alternatives. HFC and FC compounds results in higher extinguishing concentrations. hence. ie. The lack of significant chain breaking reaction inhibition in the flame zone by HCFC.100% These are clean agents stored as pressurised gases and. Other replacement agents primarily extinguish the fires reducing the flame temperature by a combination of heat of vapourisation. (b) Inert gas agents suppress flames by reducing the flame temperature below combustion reaction thresholds.541(mixture of N2 52%. as given in one HTOC document is reproduced overleaf: (b) Table-2 showing the physical properties of Halocarbon Gaseous Agents for Fixed Systems is given in page 154.0 Page 155 . IITK-GSDMA-Fire 05-V3. relative to Halon 1301.2. relative to Halon 1301. heat capacity and the energy absorbed by the decomposition of the agent. They are electrically nonconductive. If oxygen concentration is reduced below 12 % (in air) most of the flaming fires will be extinguished 7.5.3. results in higher levels of agent decomposition.IG . form stable mixtures in air. Extinguishing Properties: (a) Halocarbon clean agents extinguish fires by a combination of chemical and physical mechanisms. 7.5. by inhibition of free radicals. require substantially greater storage volume. This is achieved mainly by reducing the oxygen concentration. Argon(A) 40% and CO2 8% (ii) Argonite .IG . On the other hand.. Oxygen depletion also plays an important role in reducing flame temperature.IG 01 (A) 100% (iv) Nitrogen .12. or breaking chain reaction. and leave no residue.55 (mixture of N2 50% and A 50% and (iii) Argon . HBFC and HFC compounds are similar to Halon 1301 in chemical suppression mechanisms.
Physical Properties IITK-GSDMA-Fire 05-V3.0 Handbook on Building Fire Codes Page 156 .Table-I New Technology Halon Alternatives Table-2 .
Handbook on Building Fire Codes IITK-GSDMA-Fire 05-V3.Halocarbon Gaseous Agents Page 157 .0 Table-2 Physical Properties .
Handbook on Building Fire Codes (c) Table-3 showing Minimum Extinguishing Concentrating and Agent Exposure Limits of Halocarbon Gaseous Agents is given below: IITK-GSDMA-Fire 05-V3.0 Table-3 Minimum Extinguishing Concentrations.Halocarbon Gaseous Agents Page 158 .
Use of agents upto the LOAEL has been permitted in occupied areas if adequate time delays and pre-discharge alarms are provided and time required for escape was short(HTOC). and Atmospheric Life Time (ALT) (ii) It is important to select the fire protection choice with the lowest environmental impact that will adequately provide the necessary fire protection performance for the specific applications. and (ii) specific biological effects.0 Page 159 .14 % will not support flaming combustion. Global Warming Potential(GWP). and Table-5 showing the Toxicity.50 % by volume.Handbook on Building Fire Codes (d) Toxicity: Toxicity tests are conducted based on (i) the duration and frequency of the exposure. It has been recommended that Halon replacement agents should not normally be used at concentrations above the NOAEL in occupied areas. New recommendations are under proposal: (e) Environmental Factors: (i) As far as Halon Alternative Clean Agents are concerned. and Lowest Observed Adverse Effect Level (LOAEL). the primary environmental factors to be considered are: Ozone Depletion Potential(ODP). For Halocarbon agents. These inert gas agents are electrically non-conductive and clean for fire suppression. It is known that for most typical fuels. They differ from Halocarbon agents in the undermentioned ways: IITK-GSDMA-Fire 05-V3. which reduces the ambient oxygen concentrations to between 14 % to 10% by volume respectively. (f) Inert Gases are used in design concentrations of 35 . oxygen concentrations below 12 . (iii)Table 4 showing the Environmental Factors for the Halocarbon Gasceous Agents. The two terms normally used while referring to toxicity are: No Observed Adverse Effect Level (NOAEL). Storage and the Environmental Factors for INERT Gases are shown at pages 158 & 159 respectively. these levels are usually driven by the cardio-sensitisation level of the agent.
Environmental Factors for Halocarbon Gaseous Agents Page 160 .0 Table-4.Handbook on Building Fire Codes IITK-GSDMA-Fire 05-V3.
Inert Gases Page 161 .0 Table-5 .Handbook on Building Fire Codes IITK-GSDMA-Fire 05-V3.
Explosion Inerting: (a) Explosion inertion is an important application area of total flooding fire suppressants. There is no concern regarding the ODP or GWP potential for inert gas systems.12. This reduces the pipe thickness requirements. require high pressure storage cylinders with weight impact. (b) Explosion suppression systems employ rapid delivery of the agent following very early detection of an ignition. 7.Handbook on Building Fire Codes They are not liquefied gases.5. with appropriate predischarge alarms. (b) The enclosure's integrity should be sufficient to prevent (i) preferential agent loss during discharge. Discharge times are about 1 to 2 min. They are stored as high pressure gases and. Inert gas agents are not subject to thermal decomposition and. and alleviates concerns regarding high pressure discharges. form no by-products. The total agent delivery time is on the order of 1min. Clean Agent System Design: (a) Detection and Actuation System is a critical and integral part of a clean agent system design.12. Many countries have granted health and safety approval for use of inert gases in occupied areas in the workplace. The detection system should be designed to actuate the system.0 Page 162 . This is particularly important. since thermal decomposition products of halocarbon clean agents are a concern. hence. This may limit some applications involving very rapidly developing fires.5. These systems use pressure reducing devices at or near the discharge manifold. IITK-GSDMA-Fire 05-V3. Suppression of detonations requires substantially higher agent concentrations 7. Such systems employ significantly higher agent quantities (than flame suppression or inertion) delivered at higher rates. and (ii) excessive agent /air mixture loss after discharge to ensure adequate hold time. The inerting concentration of an agent is the concentration required to prevent unwanted pressure increases in a premixed fuel/air/agent mixture subjected to an ignition source. therefore.5.4.
testing and maintenance of the systems. full-scale third party approval testing should be conducted using the manufacturer's hardware on n-heptane. extreme care and attention should be given in the selection of system. (f) It is gathered that consideration is being given to the need for raising the safety factor from 20% to 30%. including doors.Handbook on Building Fire Codes (c) All openings. (h) The selection of an agent should be made on its fire performance characteristics.6. and selected flammable liquids. 7. toxicity(particularly for use in unoccupied areas) and the availability of approved system hardware. agent and system space and weight concerns. (e) In so far as clean agents are concerned. System installation in rooms with unenclosable openings should not be attempted with these agents (d) Minimum design concentrations for Halon 1301 were set by the cup burner extinguishing concentration plus a 20% safety factor. (i) In the background of relative lack of experience with systems employing these new agents. the minimum extinguishing concentrations as determined by the cup burner method must be established. The move for increasing the safety factor to 30% resulted from a combination of theoretical analysis and fire testing. A minimum Halon 1301 design concentration of 5% was also established for all applications. installation. Details of these tests will be available in relevant standards. GRAPHIC SYMBOLS FOR FIRE PROTECTION PLANS: 7.0 Page 163 . (g) The use of Halon alternative agents must be consistent with applicable environmental regulations. and aspects like design. in conjunction with the detection and alarm system.6. wood crib. inspection. must be secured prior to discharge. ventilators etc. While making out Fire Protection Plan Drawings certain stan dard graphic symbols are required to be used for identifications of various fire protection equipment and systems recommended for IITK-GSDMA-Fire 05-V3.1. Following this by the system manufacturer.
IS 12349-1988. "Fire Protection-Safety Signs" is also reproduced at Annex J..SAFETY SIGNS Safety signs pertaining to fire protection/means of exit have come to be universally accepted and adopted as international standards.0 Page 164 . as stipulated in IS:12407-1988. particularly in the Tourism leisure (Hotels) and Aviation Industries.Handbook on Building Fire Codes incorporation in the Fire Protection Plans of the premises concerned. construction of buildings and installation inspection and maintenance of the fire protection systems and equipment and the implementation of the Plan in its entirety are required to be well conversant with these symbols. These have come to be adopted for Assembly buildings like Cinema Theatres. These graphic symbols. for information and guidance.7. are reproduced at Annex I for information and guidance. 7. IITK-GSDMA-Fire 05-V3. "Graphic Symbols for Fire Protection Plans". All those concerned with the design. FIRE PROTECTION . Auditoriums etc.
1 General (a) All fires start small. water and sand buckets could be seen distributed for tackling small fires.water buckets for tackling ordinary fires. Even now. (b) In the earlier days. in the absence of any other present day equipment. the maximum weight of portable extinguishers has been specified as 23 kg. w h i c h a r e o f comparatively smaller size.0 Page 165 .FIRST AID FIRE FIGHTING EQUIPMENT 8. (c) Portable fire extinguishers are specially designed for the purpose of tackling fires in their incipient stage. These bigger sizes of extinguishers also come under the broad term of first aid fire fighting equipment. and sand buckets for oil fires. and if immediately tackled with proper type and amount of extinguishing medium. (d) The term 'portable'. as well as Railway and other remotely located public premises. and has assumed the front position among the fire protection measures for all types of occupancies as well as fire risks. there are bigger size of extinguishers which are trolley-mounted and could be pulled to the desired spot. including European standards. can be easly extinguished. IITK-GSDMA-Fire 05-V3.Handbook on Building Fire Codes CHAPTER -5. In some of the foreign standards. (e) A p a r t f r o m p o r t a b l e e x t i n g u i s h e r s . portable buckets filled with water and sand were used for tackling incipient fires . in rural areas. they are now considered as the first line of defence in fire fighting operations. when applied to fire extinguishers. implies that they can be carried manually to any desired fire scene and operated by one person. and they are now very commonly used for the same purpose. Infact.
The maximum size of the gas cartridge is 60 g for a 9 litre extinguisher. IITK-GSDMA-Fire 05-V3. which forces the extinguishing medium out through a nozzle. which can be projected on to the fire. (iii) The gas cartridge is screwed on to a holder which is fitted on to the cap of the extinguisher. In other types.2 Types of Extinguishers: (a) Portable fire extinguishers can be divided into 5 categories according to the extinguishing agent they contain: (i) Water type extinguishers.. the gas which comes out of the cartridge drives out the extinguishing medium. (b) They can also be grouped into categories according to their method of operation. and the second one is known by the name stored pressure type of extinguisher. the water jet should give an effective throw of not less than 6m for a minimum period of 60 sec. Extinguishers can be operated by the use of air or gas pressure in the upper part of the container. the pressurising agent (air or inert gas) is stored inside the upper portion of the extinguisher itself. by striking the knob on the top. when filled to the specified level. and (v) Halon / Halon alternative type extinguishers. (iii) Dry powder extinguishers. When the cartridge is pierced. 35 bars).0 Page 166 . and at least 95 % of water in the extinguisher should be discharged. (ii) Foam extinguishers. On puncturing the cartridge. (iv)CO2 extinguishers. The cartridge is pressurised with CO2 gas (to a pressure of approx. (iv) On operation. it expels the water from the body of the extinguisher. (ii) The liquid capacity of the extinguisher. the gas is released.Handbook on Building Fire Codes 8. and therefore the body of the extinguisher remains permanently pressurised. They can also be operated using a cartridge containing an inert gas (normally CO2) under pressure. (c) Water(gas cartridge) type extinguisher: (i) In this pressure is released from a cartridge which is stored inside the body of the extinguisher. gas cartridge type of extinguisher. is 9 litres. The expelled water comes out through the nozzle of the extinguisher in the form of a small jet. and on coming out of the cartridge. The first one is known by the name.
depressing the valve lever and directing the water jet by means of the hose. The air can be supplied by compressed air cylinders or by certain type of pump. (ii) (iii) As this type of extinguisher is permenantly pressurised.0 Page 167 .Handbook on Building Fire Codes Fig-57 Water(Gas Cartridge) type extinguisher (d) Water(Stored Pressure) Extinguisher: (i) The extinguisher is filled with water and dry air pressurised up to 10 bars. Operation is performed by withdrawing the safety pin. (iv) The normal capacity of this extinguisher is also 9 litres. it can only be opened for inspection after discharged. IITK-GSDMA-Fire 05-V3.
0 Page 168 .Handbook on Building Fire Codes Fig-58 Water(Stored Pressure) type extinguisher IITK-GSDMA-Fire 05-V3.
Handbook on Building Fire Codes (e) Mechanical Foam Extinguisher (9 L): (i) (ii) The extinguisher is filled with pre-mixed foam solution(AFFF) Foam extinguisher can either be of the stored pressure type. (iv) The figures of the two types are shown below: Fig-59-A Mechanical Foam Extinguisher (Stored Pressure Type) Fig-59-B Mechanical Foam Extinguisher (Gas CartridgeType) IITK-GSDMA-Fire 05-V3. (iii) The operation of these types is similar to what has been stated under the water type extinguishers.0 Page 169 . or gas cartridge type.
Handbook on Building Fire Codes Fig-60 Method of Operation of Foam Extinguisher (f) (i) Dry Powder Extinguisher: Various types of dry powder extinguishers are available in the market. It is normally fitted with a pressure gauge and a fan-shaped nozzle. (iii) Dry Powder Extinguisher(stored pressure type): The construction of this type of extinguisher is similar to that of water(stored pressure type). and some suitable for class A B C fires. (ii) As already stated under Extinguishing Media chapter. Some of them are filled with dry powders suitable for class B & C fires.0 Page 170 . for permanent extinguishment. The pressure maintained inside the extinguisher is about 10 bars. dry chemical powders have excellent fire knocking down properties. their use will have to be followed with discharge of extinguishing media like foam or water. However. more often. The throw of jet. and duration of discharge for extinguishers of different capacities are given overleaf: IITK-GSDMA-Fire 05-V3.
5 Not less than 4 Not less than 4 1) From nozzle to centre of pattern of discharge.5 1 and 2 5 and 10 Minimum Period Which Throw of Jet Will be Maintained s 5 6 15 Maximum Period Discharge at Least 85 % of Contents s 8 12 25 Range or throw of Jet m Not less than 1. Fig-61-A Dry Powder Extinguisher(Stored Pressue) type IITK-GSDMA-Fire 05-V3.0 Page 171 .Handbook on Building Fire Codes Capacity of Fire Extinguisher kg 0.
Handbook on Building Fire Codes (iv) Dry Powder Extinguisher (Gas Cartridge) type: 4 sizes of extinguishers of this type are available in the market .0 Page 172 . The sizes of the gas cartridges also vary according to the extinguisher size. viz. 2kg.5kg. Fig-61-B Dry Powder Extinguisher(Gas Cartridge) .. 5kg & 10 kg capacities. 3kg and 4.two types (g) CO2 Extinguisher: The main features of this extinguisher are: It consists basically of a high pressure cylinder. 9kg and 22. Trolley mounted types are of capacities 6.5kg.5 kg (portable types). The discharge time etc. The CO2 is retained mostly in a liquid condition at about 51 bars pressure (at a temperature of 15oC) Different capacities are available. 2kg.1kg. This type of extinguisher is quite common as a requirement for various type of occupancies. of various types are given overleaf: IITK-GSDMA-Fire 05-V3.
sec.Handbook on Building Fire Codes Nominal Size of Extinguisher. kg Discharge Time. it dilutes the oxygen supply and makes human survival difficult.0 Page 173 . CO2 will not support life when used in large quantities to extinguish a fire. If used in an unventilated area.5 6.5 8 10 10 10 12 20 Fig-62 CO 2 Extinguisher Hazards of CO2 extinguishers: Although not itself toxic. Min Max 18 20 24 30 36 60 2 3 4.5 9 22. A thick cloud of CO2 gas may cause disorientation IITK-GSDMA-Fire 05-V3.
so that maximum advantage can be gained for promotion of fire safety standards for their own benefit.The most important considerations while selecting extinguishers are the nature of the area to be protected. 8.0 Page 174 . his training and experience in its operation and his self-confidence.1992 (which is under revision). means a complete and thorough examination of each extinguisher. cleaning. 8. examining all its parts.4. Inspection and Maintenance of Fire Extinguishers: 8.1. A maintenance check involves opening the extinguisher. Another factor to be considered is the human element involved. (vii) Soda Acid & Chemical Foam Extinguishers have already been phased out. replacing defective parts.4. The standard capacities of these extinguishers are 1. is very important. 2. 8. as distinguished from inspection.2. An individual's reaction to a fire will be largely influenced by his familiarity with the extinguishers. hydrostatic pressure testing. and refilling of extinguishers are given in IS:2190-1992 which should be scrupulously followed.3.25 kg.3. Selection and Installation of Extinguishers: 8.3.4. 5 kg & 6. Maintenance. where necessary. 4 kg. An inspection is a quick check that visually determinds that the fire extinguisher is properly placed and will operate 8. installation and maintenance of first-aid fire extinguishers are contained in IS:2190 . Detailed instructions regarding periodical maintenance.getting phased out.2. Training. reassembling. and their IS withdrawn. It is essential that all users (at least organisations) should be quite familiar with these instructions. therefore. They are getting replaced gradually by other extinguishers containing Halon alternatives. 8. recharging and repressurising the extinguisher.5 kg.Handbook on Building Fire Codes (vi) Halon Extinguishers: In India Halon 1211 extinguishers are still avialable although they are.1. IITK-GSDMA-Fire 05-V3.3.5 kg. Detailed instructions regarding selection. They are quite effective on fires in electrical / electronic equipment. and the nature of the hazard involved.4.
Based on occupancy. These hazards have been instrumental in causing heavy losses in lives and property. Mercantile. General Building.0 Page 175 . or for other purposes. throwing up fresh challenges to planners. Fire hazards in buildings: An overview Right from the history of mankind. 9. forms an integral and major constituent of human habitat. Great Fire of New Orleans in 1788. Industrial. The Great Bombay Fire in 1803. architects and fire protection services in evolving better and improved methods of design and fire protection in order to mitigate such losses. Assembly.Residential.1. including high-rise buildings. Any laxity in the control of these hazards in the buildings can lead to mass disasters. Business. explosions and other hazards which these buildings are exposed to. fire has been a constant threat to human habitations and instances are several when cities or a major part of them had been raced to the ground by conflagrations. not only the factor of susceptibility but the complexity of fires. Educational. especially in the urban areas. 9. Storage and Hazardous. but also for the fact that they IITK-GSDMA-Fire 05-V3.. working. With the technological advance on all fronts. whether used for living. As a sequel to the all round socio-economic progress our country has been making. have also increased manifold. buildings come under one or the other of the following general classifications . are well known. Some of these disastrous fires during the last few centuries like: The Great Fire of London in 1666. Sansfransico Fire in 1851. The Great New York Fire in 1835. not only for the immense loss of life and destruction of property they had caused to mankind. Chicago Fire in Oct . there had been enormous increase in the number of buildings of all classifications. 1871.BUILDING FIRE HAZARDS 9. Institutional.Handbook on Building Fire Codes SECTION 5 . etc.2.
which arise inside the building and which concern the safety of the occupants (Personal Hazard or more widely known as Life Hazard): and which concerns the safety of the structure and the contents. heat and toxic gases build up over time to create an environment leading to a critical level when survival of life becomes impossible. 9. whereas a Storage occupancy will have primarily a damage hazard. 'fire load' of the building. as everybody's concern is to save and protect lives from fires. including the human factor.which arise as a result of fires in surrounding property (Exposure Hazard) The relative degree of each of these hazards will vary according to the type of occupancy of the building .0 Page 176 . The lead time for this can be very short. smoke. ie. degree of fire resistance. age of the building. fire prevention. the type of building services. and will vary according to the material on IITK-GSDMA-Fire 05-V3.. and scores of others. the type of occupancy. The susceptibility of buildings to fire depends on several factors like: Type and size of building. method of construction. and (ii) External hazards . hazard to the structure and contents.Handbook on Building Fire Codes eventually led to the origin of the metropolitan fire services in these cities.An Assembly occupancy will be having predominently life hazards. As a fire develops. for purposes of analysis of the various fire hazards in buildings it is common to divide these hazards into: (i) Internal hazards. However. combustibility of materials of construction. and fire protection arrangements of the building.3 Relationship of Building Fire Hazards with Life Safety: The most important of these hazards which deserves the highest consideration is the life hazard.
hydrogen cyanide. Many people find it difficult to move about if the visibility is reduced by smoke to say 10m. levels. Hazards of Smoke: The main danger from smoke is that it reduces visibility and consequently the occupant may not be able to identify escape routes and utilise them.0 Page 177 .5%) can be fatal in 2 to 3 mins.000 ppm (1%) in about 1 minute! In a confined smouldering fire more quantities of CO are likely to be present as compared to a freely burning fire in a well ventilated room. This is the reason why lot of emphasis is laid on the need for early detection of fire conditions especially when life hazard is involved. and more precisely. Many new materials used in building construction. for determining smoke density and CO. Death can result from oxygen deprivation in the blood stream caused by replacement of oxygen (02) in the blood haemoglobin by CO . Therefore. If unchecked. hydrogen chloride. Nearly three-fourths of all building related fire deaths are from inhalation of the smoke and toxic gases produced in fires rather than from exposure to flame or heat.The danger is enhanced by evolution of large quantities of carbon-di-oxide (Co2) which contributes to increased breathing rates. It has been shown from full scale room fire tests conducted by NBS. that the smoke density (OD/M) at 1.5 m level rose IITK-GSDMA-Fire 05-V3. and the physical and mental characteristics of the exposed individuals which govern their endurance to withstand the adverse environments. 9. or for taking some action to overcome the fire. sulfur dioxide. like different kinds of plastic materials.The latter can combine with haemoglobin at a rate of about 210 times more readily than does O2 . oxides of Nitrogen. and 10. A concentration of CO of approx. the combustion products produced. It has been seen that such untenable conditions can develop in a room fire within an incredibly short time of two to three minutes. it is this short interval of time.4. the interval between detection and the critical level of human survical. that is available to the occupants for effecting escape. Toxic Hazards from Fire It has been the experience that the primary hazard to humans in a building fire is from smoke and toxic gases. 5000 ppm (0. etc. are the worst culprits in production of highly toxic gases such as carbon monoxide (which is produced even during fires involving conventional materials).Handbook on Building Fire Codes fire.
. which have been proving as serious threats to fire safety of buildings. 4% at 200 sec.Handbook on Building Fire Codes from 0. The thermal products of combustion account for nearly 25% of fire deaths. which far outnumber the fatalities. Non-availability of fire doors and other types of fire barriers Inadequate fire fighting/fire protection measures. Fire resistance of the elements of structure. you will find that the damage hazard will largely depend on the type of occupancy. 9. with fir plywood as compared to a smoke density level of 0. Many of the fire outbreaks have been attributed to acts of omission or commission by humans. (as compared to the TLV of 100 ppm or . The internal subdivision IITK-GSDMA-Fire 05-V3.0 Page 178 . and can vary from low hazard in office or business premises to high hazard in storage or hazardous occupancies. burn injuries. Open vertical and horizontal shafts.043 OD/M prescribed for escape routes. Unsafe building services. Bad house-keeping and storage practices.2 at 215 sec. and 6% at 390 sec. In addition. Unsafe processes. Although it will be beyond the scope of this Handbook to go into the details of each one of these factors. Unbroken large spaces. but may result in serious. Here again. had been the cause of serious fires in the past.001%). and the production of CO rose from 1% at 160 sec. to approx. are being highlighted here.2 at 200 sec. Many factors can have a bearing on this form of internal hazard such as: The type of building construction. especially for Industrial occupancies. Unfavourable human elements etc. to 1. Fire load of the building.6 Fire and Damage Hazards to the Building: The other internal hazard arising from fires within the building is the damage hazard or the hazard to the building structure and contents. Unbroken large spaces. can not only cause pain and disfigurement. long-term complications also. Combustibility of materials of construction. a few among them.
can act as a flue in spreading fire and hot gases. behind walls.Loss $ 52. Chicago on 16 Jan. 1. In one of the tests conducted at Brooklyn. Livonia. Buildings may have a wide variety of concealed spaces above false ceilings. movement of flame through a non combustible ceiling plenum space was supposed to be the cause of horizontal spread of fire in New York Plaza fire. Coventry. which had an undi vided area of approx. '69 with an undivided area of 11 acres . '67. unprotected penetrations of fire barriers. ft. which was used as an Exhibition Hall .The building was classified as non-combustible-Loss $50 m. shaft after 1 min.Handbook on Building Fire Codes of a building into compartments predetermines the escape arrangements as well as the fire spread.0 Page 179 . like service shafts. IITK-GSDMA-Fire 05-V3. the danger of fire spread can still be there because of open doors.K. It is not hard to find this type of construction in some of our factories also.on 12th Feb. besides a bituminous roof . (iv) Boston Grocery Warehouse on 5 Aug.. New York. Vertical concealed spaces. '57 (iii) Mc Cormick Place. In an uncompartmented building the whole of the occupants and the contents of the building have to be considered at risk in the event of fire. The last named. unenclosed stairways and shafts. in utility chases etc. namely concealed spaces. of starting of a fire at the bottom. U. under floors.Loss $ 15m. fire in August 1953. temperatures in excess of 815oC were recorded at the top of a 10 m.5 million sq. Fires in such concealed spaces are seldom promptly detected and are difficult to handle when once detected. had been responsible for a good no: of large loss fires. an important defence production establishment has an unbroken area of 11 across under one single roof! Even in buildings where care has been taken to divide such large areas into compartments.. Similarly. A few serious fire outbreaks which are glaring examples of this lapse are: (i) General Motors. (ii) Jaguar Car Coy. For instance.5 m. and non-fire stopped combustible concealed spaces.
9. and (3) effective heat flux. Fire Load and Fire Effects Fire load in a building has a significant influence in severity and duration of a fire. The degree of exposure hazard will depend on many factors like: Separation distances. Fire Hazards from Building Contents Outbreak of fire is more to be expected to originate in the contents of the building rather than the structure itself. in one of his articles.8. Exposure Hazard Exposure hazard is an external fire hazard which a building is exposed to. as pointed out by Dr.7. The type and extent of fixed fire protection systems installed. Combustibility of exterior walls. (i) duration (2) average temperature. These factors are mainly governed by the fire load and ventilation. is that the fire severity and.. 9. as prevailing ventilation also plays a significant role in determining the fire behaviour. as well as the possibility of explosion. since a building on fire can cause a fire hazard to other adjoining buildings or structures by exposing them to heat by radiation. But it is now proved that fire load as a sole determinant of fire severity of damage potential is wrong. Wind direction. viz. Severity of the fire. IITK-GSDMA-Fire 05-V3. The explosion hazard can also be from adjoining open storage yards. if any. therefore. The hazard of the contents will also govern the rate of spread of fire. The duration and severity of fire mainly depends on ventilation and fire load. In well ventilated buildings with large windows. the smoke propagation. Roorkee]. the fire damage that may be expected.Handbook on Building Fire Codes 9. convective currents. interior finish and elements of construction.9. the fire burns readily and very high temperatures are created. In a normal building the fire load includes the combustible contents. The present view. or to the danger from flying brands of the fire. are influenced by 3 independent factors of the fire during its fully-developed period. the fire load and the types of processes or operations conducted in the building.0 Page 180 . The degree of hazard is usually determined by the combustion characteristics of the contents. Badami [Founder & Head of Fire Research Division CBRI. Fire load is a measure of the maximum heat that would be released if all the combustibles in a fire area burned.
'74. Kentucky. openings in exposing wall.K. regulations exist to check the indiscriminate use of cellular or foamed or other dangerous plastic materials for interior finish. This phenomenon is caused by thermal radiation feed-back from the ceiling and upper walls heated by the fire. Air conditioning. When all the combustibles in the space have become heated to their ignition temperatures. including a variety of wall coverings. Heating.Handbook on Building Fire Codes Width and height of exposing fire. inNov. all of which took a heavy toll of lives. This has been responsible for rapid fire spread and contributing to some of the worst fires.S. simultaneous ignition of all the contents occurs. and U. and can be instrumental in turning single building fire into a conflagration..10. which gradually heats the contents of the fire area. and most typical of all. Ventilation. and the fire becomes a fully developed one. This generally consists of those materials or combinations of materials that form the exposed interior surfaces of walls and ceilings. Sao Paulo in Feb. the most commonly used being different kinds of plastics. 9. given the required conditions. the Stardust Disco. in May '77.11. In countries like U. Combustible interior finish was found to be the main cause for the tragic fire outbreaks in: Joelma Bldg. IITK-GSDMA-Fire 05-V3. Coconut Grove Night Club. Hazards from Building Services Building services include: Electrical installations. Boston. fire in 1981. The exposure hazard has a direct relationship with fire spread. Interior finish is one of the three principal elements' which determine the fire hazard potential of a building. etc. Hazards from Interior Finish As stated earlier. '42. Dublin. Interior finish plays an important role in the occurrence of "flash-over".0 Page 181 . Beverley Hills Supper Club. 9. The materials used for interior finish in modern buildings are numerous.
'72 is yet another case. They may or may not be accompanied by fire damage. Unless these services and utilities are properly designed and installed. It is the vertical and other shafts.12. including dusts. especially in plants handling or processing flammable gases/ chemicals or explosive substances. which are often neglected from fire protection point of view. '65 is one case. 1974 is a unique instance as illustration) calling for the most carefully planned and designed explosion damage control measures. rooms IITK-GSDMA-Fire 05-V3. 9. Explosions are probably the most destructive industrial accidents (the Flix Borough Plant explosion and fire on 1st Jan. Plumbing. and even hamper fire control and evacuation operations. but smoke and gases spread through the A/c system upto the 28th floor. Transportation and conveyance systems. Bombay. and which present considerable fire hazards. where the fire had originated in the 2nd floor.Handbook on Building Fire Codes Refuse disposal. although fire is a principal cause of accidents involving explosive materials. Explosion protection systems.0 Page 182 . forcing evacuation of all the 3000 occupants of the building below the 29th floor. fire in Jan. Communications. Realising their potential hazards and also their utility. Explosion Hazards in Buildings Explosion hazards in buildings are mostly associated with industrial or hazardous occupancies. death and destruction. should be considered for equipment. There have been several fire incidents to bear out this point. or cause fire and smoke spread. which are used for passing these services through floors. They can cause devastating damage. and also help in mitigation of the fire effects. walls or other partitions. it is extremely difficult to prevent spread of heat. The New York Hilton Hotel fire in Dec. designers prefer to adopt a carefully planned and integrated system of building services which can reduce the fire hazards to the minimum. smoke and gas beyond the compartment through the air conditioning system. in addition to explosion prevention measures. they can lead to fire outbreaks in buildings. The State Bank of India. housings. It has been found that although the fire itself may be confined to the compartment of origin.
It was a 9 -storey building. toiled for many days in the rescue work.Handbook on Building Fire Codes and buildings associated with manufacture.Residential building collapsed in which the number of persons who died were as high as 114. 45 who died were living on the 2 upper storeys of the 80 year old building. '85-The worst ever house collapse in Bombay Killing 43 people. Sept. and rescue work continued for one month! 3. In Surat on 9-7-1981. as well as to fire fighters during fire fighting and rescue operations. handling. The building was surveyed only 3 weeks earlier. Hazards from Building Collapses Besides fire and explosion hazards. IITK-GSDMA-Fire 05-V3.0 Page 183 .12. effects of blast or strong winds. The cause of the collapse had been surmised as the walls getting weakened over the years by constant vibrations caused by power looms located immediately behind. besides the building being old. helped by many other workers. Fire brigade rescued 100 people (35 injured). In our country there had been number of collapses of buildings in the recent past. some of which are enumerated hereunder: 1) August '83. Bombay collapsed in which over 20 died and rescue operations went on for 2 weeks or so.housing Shantinath Silk Mills collapsed following a boiler explosion. a four storeyed RCC building . The collapse of structural building elements can be a serious hazard to occupants and have often caused large number of casualties of persons inside. processing and storage of such materials which have an explosion potential. 2. was its nearness to railway track and possible consequent structural instability caused due to vibration during frequent rail movements. 13. Aug. 4. and ground floor was occupied as shops and presses. 9. another very important hazard which buildings are subjected to is the likelihood of collapse of a structure due to various reasons like old age of the building. 98 dead bodies were recovered and 105 injured casualties were rescued within 5 days.13. Nearly 200 firemen. or due to fire or explosion effects.Akashdeep multi-storyed bldg. '83-Bangalore . earthquake. including 18 children. and passed. One of the reasons for the collapse.
Roof collapse of the auditorium in Dhaka Bangladesh . Over 900 were treated in hopitals.0 Page 184 .Mukesh Dyeing Mills fire followed by building collapse (Night) .20 Firemen. 7. fire safety and fire protection requirements in general. In fact. It is gathered that the fire protection experts of these countries will be meeting soon in the one of the European countries for discussing this problem. exit requirements. particularly because of the fact that hardly any fire prevention measures are observed during this stage by the contractor and their workers.A 5 storey Dept.15. the management also seldom ensures proper observance of the fire protection measures during construction work. 9. Korea .3 dimensional fire due to leaking oil from a boiler . Besides.Handbook on Building Fire Codes 5. 9. Rescue work hampered due to lack of equipment. including a Fire Officer and 2 others got killed. NBC Part-4 Provisions Detailed guidelines and norms regarding types of building construction. 29-6-95. special fire safety and fire protection requirements for multi-storey IITK-GSDMA-Fire 05-V3. fire zoning.At least 74 died and 28 injured. who were watching a night TV programme. Constructional Practices and Safety. 6.16. There are provisions in the National Building Code and some of the municipal Building Bye-laws which make it incumbent on the contractor to observe fire safety precautions and to appoint a fully trained official who should be present at the work spot throughout for ensuring compliance with all fire safety measures. as well as for all the nine different types of occupancies. this has been showing an alarming rising trend causing great concern to all. Store.Surat . S.Detailed guidelines on this are given in NBC part 7. crowded with shoppers collapsed. 14-12-91 . mostly students. in the developed countries. 15-10-85 . Fire Hazards during Building Construction During building constructions also the fire hazards are predominant. 9.14:Arson and Incendiarism The cases of building fires and explosions deliberately caused by miscreants have been on the increase the world over. structural fire protection requirements. killing over 100 & injuring nearly 1000.
and the guidelines for fire drill and evacuation procedures for high-rise buildings.17. they should be recognised only as minimum requirements consistent with reasonable public safety. However. guidelines for selection of fire detectors. it is possible to relate the use and amount of combustibles to a common datum in an attempt to balance the fire risks among different types of building construction and different occupancies. both active and passive. 9. While formulating a fire protection scheme for any premises. Need for an Integrated Approach on Fire Safety In the present days.0 Page 185 . IITK-GSDMA-Fire 05-V3. it will be necessary to have an integrated approach to the problem starting right from the design stage. are given in Part IV of the NBC. It has to be borne in mind that the ability of the fire service to contain or extinguish a fire is considerably reduced if the fire spread is faster than it could be controlled effectively. and thus bring about optimum fire safety. However.Handbook on Building Fire Codes buildings (above 15 in. ht. are incorporated while finalising the design of the occupancy. it is perhaps impractical to totally eliminate all fire hazards from buildings. fire protection considerations for venting in industrial buildings. because of lack of proper fire safety design and constructions of the building. but not necessarily as criteria for complete safety or ideal conditions. thereby ensuring that adequate and suitable fire protection measures.).
therefore their susceptibility to fire and fire products are to be assessed correctly to evolve a safe evacuation plan for them. depending upon the nature of the fire and the surroundings. including inadequate fire and life safety measures incorporated in the building. The progress of the deterioration of the environment is beyond prediction.1. However. when the environment deterioration reaches the critical level. disability. 10. mobility (including physical handicaps. As a fire develops in a building. or evacuation of occupants.Handbook on Building Fire Codes SECTION 6 .0 Page 186 . either by persons around or by automatic fire detectors. illness etc. The interval of the time between detection and criticality is the time available to undertake or initiate life saving measures. Most fires develop slowly at first when conditions of human survival are comparatively safe. Fire and Life Safety A building on fire poses a life hazard problem to the occupants of the building. The characteristics of the building occupants to be taken into account are their age. Factors affecting Life Safety of Occupants. many of which are beyond control. the fire will be detected. the intensity of the fire increases sharply creating serious survival problems. These measures may include various actions like activation of manual or automatic equipment for fire fire suppression .). since there are great many variables involved. life hazards to occupants in the building assume serious proportions. due to several reasons. alertness or IITK-GSDMA-Fire 05-V3. The most difficult component of life safety to evaluate is the occupant population at risk in the building and.2. When the products of combustion reach a certain level of accumulation. As mentioned earlier.LIFE HAZARDS IN BUILDINGS AND MEANS OF ESCAPE / EGRESS / EXIT 10. which has potential to develop into a major life loss catastrophe. smoke and heat build up to create an environment which is dangerous to life.
and their amenability to disciplinary control. smoke . Studies have shown the relationship of occupant density with speed of movement in case of forced evacuation. Danger from panic is greater when a large number of people are trapped in a confined area. Large complex structures such as multi-storeyed shopping malls. Occupant density in the building is also quite relevant due to the fact greater the number of people in a given area. making human survival difficult. Materials burning near a wall will have a faster rate of fire growth than materials burning in the centre of the room.3. It is for this reason that fire detection and action to protect or rescue the occupants have to be speedily initiated during this stage itself. The spread of smoke and fire to the other parts of the building exposes the occupants in these areas also to survival problems. may be conducive to panic.Handbook on Building Fire Codes awareness (which may be influenced by alcohol and narcotics. This is because of the re-radiation from the heated walls to back to the burning fuel. atrium buildings etc. the presence of smoke or fumes and the stoppage of travel towards the exit. IITK-GSDMA-Fire 05-V3. plenums. require thorough planning and design for smoke control measures. void spaces and even windows can all contribute to spread of fire and smoke. which may lead to panic conditions Any uncertainty as to the location or adequacy of means of egress. such as may occur when one person stumbles and falls on stairs. Building features such as vertical shafts. maintained and operated as to avoid undue danger to life and safety of the occupants from fire. eventually leading to 'flashover'. Regular occupants of a particular building are likely to have better familiarity and knowledge about the premises as against casual or transient visitors to the building. 10. 10. equipped. When a fire spreads across the ceiling heat build up throughout the room becomes faster. their standard of training in evacuation drills. Growth and Spread of Fire and Smoke The fire growth stage is the most important to life safety.4. occupant density in the premises. It is in this stage that the space or room of fire origin eventually becomes uninhabitable. familiarity with the lay out of the premises. ducts. greater is the potential loss of life. fumes or panic during the survival time available for escape. Nature of Fire in Buildings Every building shall be so constructed. or whether they are awake or asleep).0 Page 187 . Occupants survivability becomes impossible at this point.
This path. except in very few deserving cases.5. Availability of alternative means of exit for use. evacuation times are directly related to the fire hazard. the following are the requirements in general: Provision of adequate No. travel distance and exit capacity.6. shorter the exit time.0 Page 188 . requires a safe path of escape from the fire in the shortest possible time. heat. Good exits facilitate everyone to leave the fire area in the shortest possible time by prompt and efficient use of them. if the already chosen one is inaccessible due to fire. Provision of two separate means of exits for every floor including basements is a fundamental requirement. of properly designed. Adequate illumination and marking of the means of egress. If the fire is discovered promptly and occupants alerted also equally promptly. which should be as short as possible. smoke and toxic gases during the egress time based on occupant load. 10. Provision of refuge areas where total evacuation of occupants is not contemplated. Protection of the entire rescue path against fire. Design Considerations of Means of Exit Designing a means of egress involves more than numbers. Adoption of compartmentation and other adequate passive fire protection measures to ensure the safe egress/evacuation of the occupants in case of fire.Handbook on Building Fire Codes 10. should be ready for use in case of emergency For ensuring the life safety of occupants from a fire. However. early evacuation can be done. heat. smoke and toxic gases. unobstructed means of exit of adequate capacity which are available at all times. Formulation organisation and practice of effective evacuation drill procedures. IITK-GSDMA-Fire 05-V3. Provision of adequate and reliable fire alarm system in the building to alert the occupants. and easily negotiable. Means of Escape Requirements Safe exit for the occupants in a building on fire. flow rates and densities. higher the hazard.
IITK-GSDMA-Fire 05-V3. shall be adequately ventilated.General The details of some of the means of exit or egress or escape is a continuous path of travel from any point in a building or structure to the open air outside at ground level.Handbook on Building Fire Codes In general. including staircases. Sub division of areas to provide sufficient areas of refuge for occupants where evacuation may be delayed. Fully rehearsed exit drill procedures to ensure orderly and smooth exit. (iii) the exit discharge The main requirements for the means of exit consisting of the three constituents as given above are: All means of exit. Availability of alternate exit and means of access to it. Efficient fire alarm systems for alerting occupants and others concerned in case of fire. Control fire hazards from interior finish material 10.7. (ii) the exit . lift lobbies and corridors. Safeguarding of exits against fire and smoke during the length of time they are designed for use. Ensuring trouble free evacuation through the escape route by safeguarding of equipment and vulnerable areas from fire and smoke hazards. life safety from fire requires the following principles to be adopted:(Some of these may have already been covered earlier): Sufficient number of unobstructed exits of adequate capacity and properly designed. in case one exit is unusable due to fire. Institution of panic control measures. Exit Requirements . Adequate exit indication signs to help evacuation. Adequate lighting of exits and rescue paths. with easy access. It consists of three constituents which are: (i) the exit access.0 Page 189 . Adequate protection of vertical openings to minimize hazards from fire and smoke.
People escaping from areas filled with fire and smoke will be all anxiety to reach open air where they can breath normally and become tension-free at the earliest. An exit may also include a horizontal exit leading to an adjoining building at the same level. Even if adequate exits are provided at the initial stage. corridor. The sizes and colour of the exit signs shall be in accordance with established international practice. IITK-GSDMA-Fire 05-V3. often at the time of renovation/alteration. All exits shall provide continuous means of egress to the exterior of a building or to an exterior open space leading to a street. or to the roof of a building or a refuge area. Every building meant for human occupancy shall be provided with exits sufficient to permit safe escape of occupants.Handbook on Building Fire Codes Exits not properly ventilated can cause suffocation to people being evacuated because a large number of people would be present in such enclosed place with no natural ventilation till they get out of it and reach open air. width or protection of exits to less than that required. Exits shall be clearly visible and the route to reach such exits shall be clearly marked and signs posted to guide the occupants of the floor concerned. or external staircase. knowingly or unknowingly. No building shall be so altered as to reduce the number. passageway(s) to an internal staircase. In view of the above this requirement assumes great significance. which have access to the street.0 Page 190 . exit access or exit discharge shall be continuously maintained free of all obstructions or impediments to full use in the case of fire or other emergency. in case of fire or other emergency. or to a verandah or terrace(s). people do not give same attention to exit requirements. Every exit. Signs shall be illuminated and wired to independent electrical circuits on an alternative source of supply. An exit may be a doorway.
Lifts and Escalators for Emergency Evacuation Lift Evacuation Strategy-Modern Trends (a) Building Codes throughout the world had all along been advocating the traditional 'evacuation by stairs' policy in fire affected buildings. "Lifts and Escalators shall not be considered as exits". even when electricity is turned off.9. for high rise buildings. including some fire service personnel. Lifts and Escalators as Means of Exit According to Clause 4. especially. of Part-4 of NBC. 10. (ii) Also. 10.2. Illumination of exits and exit route signs. Years of experience have brought to focus certain facts arising from the use of staircases for evacuation in high rise buildings: IITK-GSDMA-Fire 05-V3. is very important to ensure orderly evacuation of occupants without chaos.2. when even under no-fire conditions there had been malfunctioning of the lifts. This should cover all portions of exit access. and the trapped victims had to be rescued through the intervention of the fire services. (i) This requirement has been made because of the following reasons. Under fire conditions. the chances of failure of the lifts and escalators are much more.Handbook on Building Fire Codes Normal colour used for exits is green. exits and exit discharge. to prevent spread of fire and smoke. where a funnel or flue effect may be created inducing an upward spread of fire. in India as well as abroad. there had been instances. they create a stack effect carrying the fire from floor to floor. got killed inside the lifts due to fire and smoke. The floors of areas covered for the means of exits shall be illuminated to values not less than 10 lux at floor level. In case of failure of electricity.8. and creating chaotic conditions. lifts and escalators tend to suddenly stop in between floors trapping the occupants of the lift. and instances are many when trapped victims. Moreover.0 Page 191 . Fire doors with 2 hour fire resistance shall be provided at appropriate places along the escape route and particularly at the entrance to lift lobby and stairwell. if lifts are not properly fire seperated by fire resistant shafts / lift lobbies and fire doors at every entrance.
an emergency lift control procedure is required to be developed for adoption in case of fire emergency. perhaps many more lives could have been saved. many felt that had adequate Emergency Escape Lifts(EELs) were available at WTC. provided the travel is performed without a break. Past experience combined with research studies conducted during the last two decades. as well as NFPA Codes. Hence. smoke and heat. (c) (d) IITK-GSDMA-Fire 05-V3. (b) After the 11 Sept. Research has found that it takes about 12 to 14 mins. reliable two-way communication system for the lift cars and lift lobbies with fire control room etc. Part-5 Code of Practice for Fire fighting Stairs and Lifts'. and also for fire fighters' use during fire fighting operations. 2001. Construction and Use of Buildings. The BS. From buildings over 100 storeys in height. plus provisions for fail-safe standby electrical power for operation of lifts. it may take approx. Incidentally. for any one to reach the ground level from the top storey. of going down stairs. 'Code of Practice for Means of Escape for Disabled People' recommend the use of lifts/elevators in fire situations for evacuation of disabled persons. BS 5588. Such fatigue can lead to the persons getting dizzy. 'Fire Precautions in the Design. with provisions for special protection measures for this lift against fire. to get down to the ground level using stairs from the 42nd floor of a high rise building. evacuees may need about 5 to 6 rest stops while coming down from the topmost floor to the ground level. or slipping on the stairs. including the time spent for the rest stops. etc. WTC incident. has led to the development of a new concept of 'Emergency Elevator Evacuation System' in the developed countries.0 Page 192 . British Standard. recommend the use of lifts under emergency situations. which prolonged duration is not acceptable from any point of view.Handbook on Building Fire Codes Even normally healthy persons are liable to feel fatigued after about 5min. Further. as well as Part-8. (Research done in Hong Kong found that people begin to suffer fatigue when they have climbed down about 18 storeys or so). about 40 to 45 min.
0 Page 193 .Handbook on Building Fire Codes (e) (f) (g) The elevator lobby for Emergency Evacuation Lifts(EELs) should have a capacity of not less than 50% of the occupant load of the area served by the lobby. 10. this new method has been incorporated in the design of the present-day tallest building in the world. The 'sky lobbies' on levels 41 & 42 will serve as refuge floors and staging area for egress from the upper levels(upto 80 storeys). Some of the main features of the emergency evacuation lift strategy incorporated in this super high rise building are: The twin towers have 29 double deck elevators. The occupant load as arrived at from as indicated in Table 20 of NBC Part-4 is just for normal guidance and not to be taken as a firm requirement. All lifts will be available for use in a phased evacuation mode in an emergency. IITK-GSDMA-Fire 05-V3.10. balcony or other occupied space shall be sufficient for the occupant load thereof. The shuttle lifts(double decker lifts) provide express service between sky lobbies and ground levels. since an unforeseen hazard might occur when an unusually large crowd is present. The lobby spaces should also include 1 or 2 wheel chair space of 76cm x 122cm (30 in x 48in)for each 50 persons of the total occupant load served by that lobby. Occupant Load (a) Occupant load in a building or area is an important factor for determination of the number of exits required as well as for capacities of exits. Pressurisation of sky lobbies. Incidentally. (b) The total capacity of the means of egress for any storey.. (each having a capacity of 22 persons) out of which certain double deck lifts are designed as fire lifts. Petronas Twin Towers in Kuala Lumpur. The new concept is becoming increasingly popular in many advanced countries. Fire lifts are provided with emergency power supplies also. Malaysia. The EELs should be provided with fire fighters' emergency operation devices also. ie.
20 inches). The number of exits required for any occupancy is also arrived at based on this unit of exit width. as in theatres. is reckoned as 50cms(approx. (d) 10. conventions.The total occupants from a particular floor must evacuate within two and half minutes. and 30 m2/ person for Storage occupancy(H). Clear widths less than 250 mm shall not be counted for exit width.11. for instance). as per Part-4 NBC. and sometimes to tripping down and stampede..Handbook on Building Fire Codes (c) The occupant load in any building or portion of it shall be at least the number determined by dividing the floor area assigned to that use by the occupant load factor(floor area in m2/ person) indicated in Table 20 of NBC Part-4. which are components of means of egress or escape route. the occupant load factor or floor area in m2/ person varies between the highest value of 0. lecture/entertainment/social functions etc. Capacities of Exits The unit of the exit width. on the assumption that body width of a normal person is 50cm and that much of minimum width is required for one person while passing through an escape route including stair cases. dance floors etc. Size of the exit door/exit-way shall be calculated accordingly keeping in view the travel distance as per NBC. used to measure the capacity of any exits shall be 500mm. certain problems do arise in the case of handicapped persons or people who require assistance for evacuation in the event of fire or other emergency. doors etc. Where fixed seating arrangements exist.0 Page 194 . Similar tragedies involving heavy casualties are possible (and had happened also) in huge Assembly gatherings in the open as in religious festivals and melas(Kumbh melas.. may result in Assembly occupancies which have no fixed seating. halls. According to this Table. (b) IITK-GSDMA-Fire 05-V3. A clear width of 250mm shall be counted as an additional half unit. Note:. (a) Exit capacity is usually computed on the basis of unit of exit width which.6 m2/ person for Assembly occupancy(D) with fixed/loose seats. unpredictable situations leading to panic. Likewise.
The movement of persons results in a swaying motion which varies with individuals.ft. People have a normal tendency to avoid bodily contact with others. on stairs or in dense crowds.3 sq. The 'body ellipse' equals about 0.0 Page 195 .7 inches) accross the shoulder. will be much longer. The reduction in the evacuation time to 11/2 minutes for Type-2 construction and 1 minute for Type3 construction is obviously because of the reduced fire resistance capability of these types of constructions.) which is an average person's maximum practical standing capacity of space. doors and other components in the means of egress are related to the physical dimensions of the human body.21m2 (2. which necessitates more speedy evacuation of occupants to a place of safety. the total body sway may reach almost 100mm(4 in) In theory. the time needed to evacuate just the floors immediately at risk to a final exit. stair ways. London Transport Board had undertaken a research project on the movement of persons.Handbook on Building Fire Codes (c) The Note is persumably based on studies conducted by the Grading Committee in UK on evacuation times taken in actual fires. The time 21/2 minutes was taken as the time necessary for the total evacuation of one storey to a protected stair way and not to a final exit. During movement on stairs or in dense crowds. Results of research studies conducted abroad: The unit of exit width is based on the 'body ellipse' concept. and some of the conclusions (d) (e) (f) IITK-GSDMA-Fire 05-V3. In the case of high rise buildings. especially while on the move. and also depending on whether the movement is on level surfaces. which was used in other countries for developing design of pedestrian systems. The occupants per unit exit width to achieve this time for evacuation of total occupants from a floor will range from 25 to 50 persons for stairways. 520 mm(20. This indicates that a total width of about 760mm (30 in) would be required to accommodate a single file of persons going up or down stairs. Studies show that most adult men measure less than approx. The design and capacity of passage ways.
The roof of the shaft shall be 1 m above the surrounding roof. speeds below 44m/min.) than through a long passage of same width.) of space available per person. restricted movement on escape route under fire conditions can lead to non-adaptive behaviour of occupants. travel down stairways (of over 1.Handbook on Building Fire Codes from their Research Report No. IITK-GSDMA-Fire 05-V3.05m(10 ft. It can be 50% greater in short passages less than 3. especially when there is more than one person every 0.2m width) was determined at 0. a 813mm (32 in) doorway is considered the minimum width to accommodate a person in a wheel chair. (145 ft.ft.ft.). the vent opening shall be of 0.12. an average walking speed of 76m/min.)./ft.2m (4 ft. which restricts motion. which are listed below: crowding people into spaces less than 0.) is attained under free-flow conditions.3 m2 (25 sq.ft. of width. If the staircase cannot be ventilated.5 m2 in the external wall and the top. Glazing or glass bricks if used in staircase shafts shall have fire resistance rating of minimum 2 hours. whereas upward travel was reduced to 19 persons/min.) show shuffling. The mechanism for pressurizing the staircase shall operate automatically with the fire alarm.18 m2 (2 sq. on level surface. because of location or other reasons. under the psychological stresses during a fire./ft.0 Page 196 .) per person under non-emergency conditions may create a hazard.28m2 (3 sq.ft. (250 ft. 10. with 2. leading to a jam point with one person every 0. such crowding could contribute to crowd pressures resulting in injuries. proper egress design permits all occupants to reach a safe place before they are endangered by fire.28m2 (3 sq.) wide.) of width. flow rates are directly proportional to width for exit ways over 1./min. Internal Staircases The staircase shall be ventilated to the atmosphere at each landing with a vent at the top. smoke or heat.95 will be of interest in this present context./min. a positive pressure 50 pa shall be maintained inside.3m (21 persons/min.
0 Page 197 . No combustible material shall be used for decoration / wall paneling in the staircase. A staircase shall not be arranged round a lift shaft. Every internal escape stair should therefore be a protected stairway. Floor indicator boards in the staircases help people getting down the stairs to know on which floor they are. All buildings. the provision or otherwise of alternative staircases shall be subject to the requirements of travel distance being complied with. This also helps in reducing psychological pressure on them whilst being evacuated in case of a fire emergency.Handbook on Building Fire Codes Venting or pressurisation of staircases provide smoke-free passage to people being evacuated who face danger of suffocation by smoke inhalation. institutional. assembly. which are 15 m in height or above. Internal Stairs shall be constructed of non-combustible materials throughout. storage and haardous occupancies having area more than 500 sq. In case internal stairs form a part of the escape route. they have to be treated as escape stairs and as a 'protected stairway' to enable them fulfill their role for safe evacuation of occupants during fire emergencies. They shall be of enclosed type. IITK-GSDMA-Fire 05-V3. Further. at least one of them shall be on external wall of building and shall open directly to the exterior/interior open space or to an open place of safety. industrial. Lift shafts tend to carry smoke and fire upwards People escaping through stairs downwards must be safe from such smoke and fire. m on each floor shall have a minimum of two staircases. The exit sign with arrow indicating the way to the escape route shall be provided at a suitable height from the floor level on the wall and shall be illuminated by electric light connected to corridor circuits. and all buildings used as educational. and how far they are from the ground level where they will be safe from the fire. Smoke moves from an area of higher pressure to one of lower pressure. Pressure differences may be caused by buoyancy from the fire.
5 m 2. In general. buildings 15m in height and above shall be provided with fire lifts. These have fire hazard potential.0 Page 198 . 1. lift may be used by other persons. or protected from the ingress of smoke by a mechanical smoke control system. which is much easier and quicker than carrying them up through stairs. firemen can commandeer the lift for their exclusive use.5 m 2.0m 1. In case of fire only fireman shall operate the fire lift. theatres and cinemas d) Educational buildings up to 30 m in height e) Institutional buildings like hospitals f) All other buildings 10.0m 1. Fire Lifts This lift can be used even by building occupants except during fire emergencies. This is a lift designed to have additional protection with controls to enable it to be used under the direct control of the fire service during fires. ducting or electrical panels shall be laid in the stair way.13. For fire fighting operations in high rise buildings. The lobby should have not less than 4m2 permanent ventilation.5 m IITK-GSDMA-Fire 05-V3. A switch in a glass fronted box marked 'Fireman's Switch' placed at ground level and by operation of this switch firemen can recall the lift if it is in normal operation and utilise the lift for their use. Width of Staircase Following minimum width shall be provided for staircases: a) Residential buildings (dwellings) b) Residential hotel buildings c) Assembly buildings like auditorium.Handbook on Building Fire Codes No gas piping. In normal course. In case of fire.0 m 1. it will be almost impossible for fire fighters to carry their equipments to the upper floors of a tall building without the use of lift. Fully automated fire lifts having minimum capacity for 8 passengers with emergency switch on ground level shall be provided.
have been provided with a fire fighting shaft. By opening the hatch. Doors shall be arranged to be opened readily from the egress side whenever the building is occupied. fire brigade may be able to rescue people trapped in lifts which have suddenly stopped in case of a fire. Elevators shall be capable of orderly shut downs during earthquakes. Handrails shall be provided within 760mm (30 in) of all portions of the required egress width of stairs and ramps.Handbook on Building Fire Codes Each fire lift shall be equipped with suitable intercommunication equipment for communicating with the control room on the ground floor of the building One fire lift per 2000 m 2 of floor area shall be provided. Buildings more than 18m in height. or with a basement of more than 10 m below grade. it shall be easily operable. These fire fighting shafts are designed to facilitate access of fire fighting personnel into high rise and other special hazard buildings. and free of projections or lips that could trip stair users. The lift shall be so wired that in case of power failure. 10. The speed of the fire lift shall be such that it can reach the top floor from ground level within one minute. without perforations. so that when the car gets stuck up. Automatic changeover from normal supply to generator supply is very important because the generator room may not easily be accessible in case of a severe fire.14.0 Page 199 . IITK-GSDMA-Fire 05-V3. Fire lift should be provided with a ceiling hatch for use in case of emergency. This facility enables the fire fighting personnel to reach the fire and conduct fire fighting operations without delay and in an efficient manner. This is a protected shaft having facilities like fire fighting lifts.K.Fire fighting Shafts In U. Stair treads and landings shall be solid. it comes down at the ground level and comes to stand-still with door open. fire fighting stairs and fire fighting lobbies.
External Stairs It is desirable to provide external staircases in case of high-rise buildings. Flames can leap out of such doors and windows in external walls of affected building hampering evacuation and fire fighting operations. (a) The staircase and corridor lighting shall be on separate circuits and shall be independently connected so that it could be operated by one switch installation on the ground floor easily accessible to fire fighting staff at any time irrespective of the position of the individual control of the light points.15. Illumination of means of exit Staircase and corridor lights shall conform to the following.0 Page 200 . 10. The route to the external stairs shall be free of obstructions at all time. if any. Adjoining compartments into which horizontal evacuation is done should also have a floor area sufficient to accommodate evacuees from the adjoining compartment. when provided shall comply with the following: The flights and landings of an external escape stair should be of fire resisting construction. The alternative source of supply may be provided by battery continuously trickle charged from the electric mains. All external stairs shall be directly connected to the ground.16. It should be miniature circuit breaker type of switch so as to avoid replacement of fuse in case of crises (b) Staircase and corridor lighting shall also be connected to alternative supply. 10. progressive horizontal evacuation may also have to be adopted depending on the emergency situation and the facilities available. IITK-GSDMA-Fire 05-V3. Horizontal Exits: (a) Horizontal exits are particularly useful during fire emergencies in hospitals (health care occupancies) for evacuation of bedridden patients or patients suffering from immobility. (b) Sometimes. External stairs.Handbook on Building Fire Codes 10. No wall opening or window opens on to or close to an external stairs.7.
Miniature circuit breakers avoid frequent fuse replacement.9. particularly by physically handicapped elderly people and children. at the bottom and at doors opening into the ramp IITK-GSDMA-Fire 05-V3. shall be provided as under.whichever is higher. For floors above 24 mt and up to 39 m . refuge area of 15 sq. Refuge area providedu in excess of the requirements shall be counted towards FAR.One refuge area on the floor immediately above 24 m.8.0 Page 201 . Ramps Ramps shall comply with all the applicable requirements of stairways regarding enclosure capacity and limiting dimensions. Ramps with slopes greater than those recommended render them difficult to be used. The refuge area shall be provided on the periphery of the floor and open to air. protected with suitable railings. at-least on one side.3 sq. they must have landings located at the top. The slope of a ramp shall not exceed 1 in 10. 10. Ramps in means of egress are required to be enclosed or protected. For floors above 39 m.Handbook on Building Fire Codes One control switch at the ground level will help in putting on emergency lights for prompt illumination of escape routes.One refuge area on the floor immediately above 39 m and so on after every 15 m. Further.m or an area equivalent to 0. and hence this requirement. 10.m per person to accommodate the occupants of two consecutive floors. Refuge Areas For buildings more than 24m in height.
Fire Load isthe measure of the maximum heat that will be released if all the combustibles in a fire area burned. fire resistance ratings are given in standard intervals.2 Types of construction According to fire resistance.. 2 hrs. 3 hrs. and against a certain intensity of fire. rise on unexposed face (insulation) 11. doors and windows are 15 mins. Including wall linings. and 4 hrs. 30 mins... and in preventing the rapid spread of fire and smoke which may otherwise contribute to the loss of lives and property. namely..0 Page 202 ... 45 mins. buildings shall be classified into four categories. General The design of any building and the type of materials used in its construction are important factors in making the building resistant to a complete burn-out. Fire Resistance Rating is at times referred to as "Fire Endurance Rating" also. Type 3 construction and Type 4 construction. 1. The usual fire resistance ratings for all types of structural members.. Type 2 construction. 1hr. Type 1 construction.Handbook on Building Fire Codes SECTION 7 . The fire resistance of a building or its structural and non-structural elements is expressed in hours against a specified fire load which is expressed in kcal/m2. The fire resistance IITK-GSDMA-Fire 05-V3.FIRE SAFETY IN BUILDING DESIGN AND CONSTRUCTION BASIC PRINCIPLES 11. wooden or combustible partitions. The fire resistance of an element is the time in minutes from the start of the test until failure occurs under any one of the criteria set out below: (a) Resistance to collapse (stability) (b) Resistance to penetration of flame (integrity)] (c) Resistance to temp. While the actual time is recorded in the nearest integral minuites.resistance test for structural elements shall be done in accordance with good practice. linings/coverings on floors and ceilings. The fire . 11/2 hrs.
& 4 hrs.3 Steel Construction Bare steel members if provided would collapse under fire conditions much earlier than other structural elements like walls.. Part-4... members.e. IITK-GSDMA-Fire 05-V3. and the fire enters the segregated compartment. 2 hrs. The usual fire resistance ratings for structural assemblies. Uses of these Tables is to assess the stability of building damaged by fire. as safe For buildings 15 m in height or above. 11.0 Page 203 .Handbook on Building Fire Codes ratings for various types of construction for structural and non-structural members shall be as given in standard Tables in NBC Part-4 IS:1809-1979 deals with methods of testing structural members of different material for their fire safety. Fire damage assessment / post fire structural safety assessment of various structural elements of the building and adequacy of the structural repairs can be done using the fire resistance ratings mentioned in the tables. This reduces the overall damage and material losses. Integrity and Insulation. The fire resistance is the time duration the member or assembly can withstand the fire test without failure. For fire resistance ratings required for various structural and non-structural members to be used for different classes of construction. All supporting structural beams and columns of steel should therefore be enclosed in 5 cms (2 in) thick concrete or equivalent fire proofing material. slabs etc. stability. Perfect party walls have minimum fire resistance of 4 hrs. please refer to standard Tables in NBC. The walls for the chimney shall be of Type 1 and Type 2 construction depending on whether the gas temperature is above 200 c or less. are: 1/2 hr. without failure by any one of thefailure crieteria listed in the fire test protocol i. noncombustible materials should be used for construction and the internal walls of staircase enclosures should be of brick work or reinforced concrete or any other material of construction with minimum of 2h rating. doors etc. Combustible materials on the other side of the fire seperating wall can be segregated before the wall collapses. 1hr. A 1hr. before declaring a building damaged by fire which has undergone repairs. rating indicates that the assembly/ member can withstand the standard test for minimum 1 hr. 3hrs.
No height restrictions for buildings in A5. or floor area ratios and the local fire fighting facilities available. and continuously maintained for the occupied part of the building Detailed Instructions on "Safety Against Fire and Fire Protection for Buildings under Construction" are given in Part-7 "Constructional Practices and Safety" under NBC. A6 & group E Note: Classification of Occupancies and Groups under them are as given in NBC Part-4. Encasement of structural steel members can be done utilizing concrete. 11. lath and plaster. 11.4 Occupation of Buildings under Construction. NBC. D & F Buildings above 18 m: Not permitted for G-1 & G-2 Occupancies. : Not permitted for occuppancies A1.6 Open Spaces The open spaces around or inside a building shall conform to the requirements of Part 3. Groups H & J Buildings above 30 m: not permitted for Groups B.Handbook on Building Fire Codes Encasement of structural steel members has been a very common and satisfactory method of insulating steel to increase its fire resistance. depending upon its occupancy and the type of construction. alterations or additions. roofs etc. Development Contro Rules and IITK-GSDMA-Fire 05-V3. C. Classification of buildings under construction or repairs gets temporarly downgraded because of opening up of walls. only if all means of exit and fire protection meaures are in place. G3. A building or portion of building may be occupied during construction.0 Page 204 . The maximum permissible height for any combination of occupancy and types of construction should be necessarily be related to the width of street fronting the building. which is also currently under revision 11. repairs. Buildings above 60 m: Not permitted for A3 & A4 Occupancies. This could be achieved by use of appropriate methodology using suitable fire resistance rated materials. gypsum board or sprayed mineral fibres Load bearing steel beams and columns shall be protected against failure / collapse of structure in case of fire. Buildings above 15m. A2.5 Maximum Height Every building shall be restricted in its height above the ground level and the number of storeys.
shall be provided for fire tender movement".1.60 ha"] 11.0 Page 205 . and Adequate passageway and clearances required for fire fighting vehicles to enter the premises shall be provided at the main entrance.00 ha. for every 200. The said open space shall be kept free of obstructions and shall be motorable". up to a height of 30 m. except in the case of residential building.Handbook on Building Fire Codes General Building Requirements.7. " The main entrance to the plot shall be of adequate width to allow easy access to the fire engine and in no case shal it measure less than 6 m. For high rise buildings. Area for Fire Station with essential residential accommodation . the width of such entrance shal lbe not less than 4.5m. A turning radium of 9m. The compulsory open spaces around the building shall not be used for parking.0. it shall have a clear head-room of not less than 5m. Other Amenities One Fire Station or Sub Fire Station within 1 km to 3kms. fire engine with their ladders cannot negotiate them incase of emergency. Area for Sub Fire Station with essential residential accommodation . Mixed Occupancy When any building is used for more than one type of occupancy in IITK-GSDMA-Fire 05-V3. If the main entrance at the boundary wall is built over.000 population has been prescribed with the following requirements. the following additional provisions of means of access to the building shall be ensured: The width of the main street on which the building abuts shall not be less than 12 m and one end of this street shall join another street not less than 12 m in width. The approach to the building and open spaces on all its sides upto 6m width and the same shall be of hard surface capable of taking the mass of fire engine weighing upto 45 tonnes. the minimum clearance shall be 4.5m. If an arch or covered gate is constructed. If entrance gate is of lesser dimension . The road shall not terminate ina dead end .
the occupancies shall not be treaed individually. the number and variety of such mixed or multiple occupancies are increasing fast. These fire stops fill the openings around penetrating items such as cable trays. conduits. wil be subject to some degree of exposure hazard either from flying brands or radiation.8 Exposure Protection Any neighboring buildings.combustible "sleeving" is also resorted to as an alternative to proprietary seals for penetration of pipes. offices. Fire stopping materials include: cement mortar gypsum-based plaster cement or gypsum vermiculite/perlite mixes IITK-GSDMA-Fire 05-V3. particularly those of more than one storey. hotel/restaurants. A recent development is the growth of so-called "multiplexes". In many of our cities. and may be a few other ancillary occupancies. it shall conform to the requirements for the occupancies of higher hazard. through the wall or floor openings. as well as the fire protection and life safety measures incorporated in the building 11.0 Page 206 . The unusually high fire and life hazards in such multiplexes can well be imagined. clinical laboratories etc. having multiple occupancies like cinema theatre.25 mm (1/4 in) thick wired glasses in steel frames 11. as a result. which are in fact one multi-level building complex. pipes etc. window and ventilator openings in the higher building are protected by 6. Consequently. the design and construction of the building. or both. Unless the high hazard area is separated by separating walls of 4th rating. ducts. Provision of non. Normally. This can be a high rise building also. which is a single building enclosing a number of tenants and occupancies such as mercantile units. restaurants. A typical example of a mixed occupancy is a covered mall building.Handbook on Building Fire Codes so far as fire safety is concerned. entertainments and amusement facilities. Fireseals This is a seal provided to close the opening or imperfection of fit or design between elements or components to eleminate the possibility of fire and smoke passing through them. shopping complex.9.
IITK-GSDMA-Fire 05-V3. crushed rock. 11. Oil filled transformers shall not be housed on any floor above the ground floor. It becomes difficult to tackle transformer fires.resisting door of 2h fire rating on both sides at the opening. The entrance to the room shall be provided with the fire. The oil filled transformers. intumescent mastics Not all of them will be suitable in every situation. or ceramic based products (with or without resin binders). A tank of reinforced cement concrete construction of adequate capacity for of accommodating the entire oil of the transformers shall be provided at a lower level to collect the oil from the catch-pit to the tank which shall be provided with flame-arrester In case of transformer fires a soakpit is required for collection of the oil draining out at a safe distance. Soak pits of approved design shall be provided. A curb (sill) of suitable height shall be provided at the entrance in order to prevent the flow of oil from ruptured transformer into other parts of the basement.0 Page 207 . If transformers are located above ground level. The switch-gears shall be housed in a room separated from the transformer bays by a fire resisting wall with fire resistance of not less than 4h. there is a danger from over flowing of the burning fuel to the floors below and even to the drains. and +. blast furnuace slag.Handbook on Building Fire Codes glass fibre. shall be protected by an automatic high velocity water spray / system if the contents exceed 2000 litres of oil. thereby removing the fuel from the fire scene.10 Transformers If transformers are housed in the building below the ground level they shall necessarily be in the first basement in a separate fire resisting room of 4h rating.
Boilers may be allowed in the basements away from escape routes. The entrance to this room shall be provided with double composite doors. Openings in separating Walls and Floors. The furnace oil tank for the boiler. A curb of suitable height shall be provided at the entrance in order to prevent the flow of oil into the boiler room in case of tank rapture.6 m2 in area with a maximum height/width of 2. Boiler rooms. The boiler room shall be provided with fresh air inlets and smoke exhausts directly to the atmosphere.Handbook on Building Fire Codes 11. Provision of catchpit ensures that escaping burning fuel flowing out of a transformer on fire does not spread to other areas.75 m . plywood etc. and this room shall be situated on the periphery of the basement. The boilers shall be installed in a fire resisting room of 4h fire resistance rating. shall be protected by a fire resistant assembly/or fire stop. Its location on the periphery ensures its easy isolation from other areas. Every wall opening shall be protected with fire-resisting doors having fire rating of not less than 2 h in accordance with accepted standards. All exterior openings in a boiler room or rooms containing central heating equipment if located below opening in another storey-or if less than 3m from other doors or windows of the same building. IITK-GSDMA-Fire 05-V3. Boilers when located in a 4 hr. if located in the adjoining room shall be separated by fire resistant wall of 4h rating.12. are used.11. * Wherever combustible materials like wood. 11. they should be rendered fire resistant by fire retardant treatment. Smoke extraction and ventilation become very important in case of fires in boiler rooms which use fuels that can generate dense smoke. fire resistant enclosure will ensure that any possible boiler explosion or fire effects are confined to the boiler enclosure and are not conveyed to outside.0 Page 208 . Entry to this room shall be provided with a door of 2h fire resistance. A doorway or opening in a separating wall on any floor shall be limited to 5.
the space between the conduits and the walls/ slabs shall be filled in by a filler material having fire resistance rating of not than one hour. to provide the following : Reasonable safety to the occupants while using the means of egress by preventing spread of fire. Further. etc. 11. shall either be armoured type or run through metal conduits/pipes. therefore. tend to buckle in fire conditions. or fumes through vertical openings from floor to floor to allow occupants to complete their use IITK-GSDMA-Fire 05-V3. For electrical shafts they shall have fire resistance of not less than 2 hours (Bus-bar system shall be desirable. In case the opening size exceeds 5. electrical wirings. fire resisting doors designed to protect them need to be adequately strengthend. The inspection door of all service shafts except electrical shafts shall have fire resistance of not less than 1 h. Provision should.Handbook on Building Fire Codes Opening in walls or floors which are necessary to be provided to allow passages of all building services like cables. be made to provide fire stopping within such spaces. plumbing pipes etc shall be protected by enclosure in the form of ducts/ shafts having a fire resistance of not less than 2 h. telephone cables. Normally doors with larger panel areas. tend to act as flues/ tunnels during a fire.14 Vertical Opening In a building fire vertical openings like stairs and lift shafts acts as flues or chimneys conveying flames.6m2.) Medium and low voltage wiring running in shafts/ducts.0 Page 209 . Door openings at every floor level leading to staircases or lifts/lift lobbies should be protected by single fire doors for safe evacuation of occupants in case of fire emergency. horizontal and vertical ducts. 11. smoke. the need for enclosure or protection of such vertical shafts to prevenet fire spread to other areas and floors served by them. as necessary.13 Concealed spaces Such spaces within a building such as space between ceiling and false ceiling. hot gases and smoke vertically and serve as channels for easy spread to the upper levels. Hence. Every vertical opening between the floors of a building shall be suitably enclosed or protected.
A/c duct work without dampers etc. Provision of fire resistant doors at every floor level helps prevention of fire spread from floor to floor. Service Ducts/Shafts.) 11. thereby limiting the smoke generation and also facilitate fire suppression.Handbook on Building Fire Codes of the means of egress. A vent opening at the top of the service shaft shall be provided having between one-fourth and one-half of the area of the shaft.16. large floor areas without separation walls.0 Page 210 . Refuse chutes which are used for collection and disposal of the waste from the various floors constitute a potential source of fire due to accumulation of combustible waste. Judicious ccmpartmentation of a building is considered as a primary method among passive fire protection measures.15 Compartmentation Helps in limitation to the damage of building and its contents : Fires on one or two floors. Service ducts and shafts shall be enclosed by waiis of 2 h and doors of 2 h. safe vaults. or when spread over a large floor area. IITK-GSDMA-Fire 05-V3. Building designs with unprotected vertical openings. To protect high value or critical areas or operations from a fire in the surrounding area (Eg: Computer rooms. records room etc. fire rating. like open stairwells. provide avenues for fire spread vertically as well as side ways. It helps to segregate a space that has a higher fire or life hazard than the surrounding area. are extremely difficult to control and extinguish by manual fire fighting methods. Limit the size of the fire. Fire figting operations become difficult and prolonged as the fire propagation continues upwards as well as horizontally. control rooms. Refuse chutes shall have openings at least 1 m above roof level for venting purpose Inspection panels and doors shall be tight fitting with 2 hours fire resistance. Natural venting of service shafts helps in smoke disposal thus making fire fighting and rescue operations easier. All such ducts/shafts shall be property sealed and fire stopped at all floor levels. Further it shall be ensured to provide a clear height of 2100 mm in the passage/ escape path of the occupants 11.
IITK-GSDMA-Fire 05-V3. when partly used as godown assumes altogether different proportion from fire safety point of view and needs to be dealt with differently. facade of building and ceiling surfaces. Interior finish materials like wall panellings.0 Page 211 . wooden floorings. possibly because of the nature of the materials involved. The use of combustible surface finishes on walls (including facade of the building) and ceilings affects the safety of occupants of a building. it is equally important to have non combustible drain pipes for obvious reasons. serious danger to life may result .18 Fire stop or enclosure of openings in external walls Total areas of windows and door openings in external walls of a building should not exceed 75% of wall area for stability of structure and for reducing exposure hazards to adjoining property. Certain aspects. It is therefore important that they have proper drainage arrangements in all the areas of the building. Such finishes tend to spread the fire even though the structural elements may be adequately fire resistant.Handbook on Building Fire Codes 11. 11. Similarly.19. Interior finish and decoration.It is therefore essential to take adequate precautions to minimize spread of flame on such walls. applicable to particular occupancies only.17. or false ceilings play equally destructive role in aggravating loss of human lives and property in case of fire. and hence these must conform to class-1 flame spread characteristics. Residence or shop. damage caused by water used in fire fighting has proved costlier than the fire damage itself. 11. Generation of large volumes of smoke and toxic gases seriously affect the life safety of the occupants. The drain pipes should be provided on the external wall for drainage of water from all floors. which may affect the spread of fumes and thus the safe evacuation of the building in case of fire are : Service equipment and storage facilities in buildings other than storage buildings. Drains Many a time.
cellular polyurethane and polystyrene materials. facade of the building. had resulted in several heavy death toll fires in the past. This can happen even in a few minutes. Class 2 may be used in any situation. also provide a large unbroken surface over which flame spreads. Class 3 Surfaces of medium flame spread Class 4 Surfaces of rapid flame spread Class 1 may be used in any situation. attaining a temperature around 600oC. The susceptibility to fire of various types of wall surfaces is determined in terms of the rate of spread of flame. (iii) It adds to the intensity of fire by contributing additional fuel. wood panelling textile wall coverings. staircase and corridors. The fourth factor is the most important since it affects occupant life safety seriously. At this stage. which is known as "flash-over" or full fire involvement.0 Page 212 .Handbook on Building Fire Codes The finishing materials used for various surfaces and decor shall be such that it shall not generate toxic smoke/fumes. IITK-GSDMA-Fire 05-V3. and combustible floor coverings. vinyl wall coverings. Class 3 may be used only in living rooms and bed rooms (but not in rooms on the roof) and only as a lining to solid walls and partitions. except on walls. and (iv) It produces toxic gases and smoke that adds to life hazard and property damage. Class 1 surfaces of very low flame spread Class 2 Surfaces of low flame spread. Based on the rate of spread of flame. all the combustible contents as well as the furnishings in the room may simultaneously get ignited. Interior finishes or linings. Interior finish affects the fire in four ways: (i) It affects the rate of heat build-up to a 'flash-over' condition (ii) It contributes to flame spread over the surface. and starts descenting from the top. The flame from the interior finish may release sufficient thermal energy for the formation of a hot gas layer which may become thick. not on staircases or corridors or facade of the building. surfacing material shall be considered as divided into four classes as follows. Use of combustible interior finishes (interior linings) such as low density fibre board ceilings.
Handbook on Building Fire Codes Note. in addition to risk from spread of fire. corridors and staircases. Setting of Glass. If the opening protected is more than 5m2 the glass loses its fire resisting property.The panels of glass shall be set in rebates or grooves not less than 6.0 mm in width or depth. Class 4 materials shall not be used in kitchens. Some materials contain bitumen and.at a very early stage. with due allowance for expansion. walls. Such materials shall be excluded from use under these conditions and shall also not be used for construction of ceiling where the plenum is used in return air in air-conditioned buildings Class 4 materials shall not be used in kitchens. This is equally true for false ceilings and false floors also. It shall not be permitted in a vestibule.20. emit dense smoke on burning. and shall be secured by hard metal fastenings to the sashes or frames independently of any cement or putty used for weather proofing purposes. securely bolted or keypad into the wall. except in case of panels in internal doors. It will give way soon. and the wired glasses would fall off defeating the very purpose for which they are provided.Panelling (lining) shall be permitted in a limited area.0 Page 213 .The Sashes or Frames or both shall be entirely of iron or other suitable metal such as stainless steel. Materials of class-4 flame spread are the worst ones for use in buildings. the support would be lost in case of a fire . and hence their use is to be strictly prohibited unless they are given proper fire retardant treatment. When frames. Sashes and Frames. If the supporting frame work to hold wired glasses is of combustible nature. of wood. eg. Wired Glass-The wired glass shall be of minimum half hour fire resistance rating. corridors and staircases. 11. partitions or floors are lined with combustible materials. IITK-GSDMA-Fire 05-V3. nullifying the very purpose for which it is installed. the surfaces on both sides of the materials shall conform to the appropriate class.
Evacuation prolonged/difficult. 15m in height or above. Rescue and fire fighting mainly from within the building. glasses will shatter and fly off in case of a fire. should be read in conjunction with the definition for 'Building Height' Some of the outstanding problems which had been experienced by the fire services during fire fighting operations in high rise buildings are: External fire fighting and rescue difficult. Large number of occupants. cement or putty used for weather-proofing purposes. traps heat and smoke during fires. Materials used in louvers wherever provided shall be of minimum half hour fire resistance rating.. Being fully airconditioned. injuring pedestrians passing by on the surrounding streets. human behaviour unpredictable. The frames and bars shall be of iron or other hard material and supported on the curb either of metal or of wood covered with sheet metal. If this is not observed. IITK-GSDMA-Fire 05-V3. The definition of high rise building. 11.The wired glass for skylights or monitor lights shall be of minimum half hour fire resistance rating.The frames shall be continuous and divided by bars spaced at not more than 700 mm centers. HIGH RISE BUILDINGS-15 M IN HEIGHT OR ABOVE. The toughened glass shall be secured by hard metal fastenings to the frame and bars independently of any lead. Incase of fire.21. viz.Handbook on Building Fire Codes Skylights Wired glass for skylights or monitor lights shall comply with the following requirements: Wired Glass for skylights or Monitor Lights.0 Page 214 . Smoke venting problems. Glasses used in facade of high rise buildings These shall have minimum of 1 hr fire resistance. Danger of flash overs. Frames and Glazing .
shall not be permitted in basements. Inlets and extracts shall be terminated at ground level with stallboard or pavement lights Stallboard and pavement lights should be marked 'SMOKE OUTLET' OR 'AIR INLET* with an indication of areas served at or near the opening. Hazards from increasing use of plastic materials.22. It shall communicate with basement through a lobby provided with fire resisting self closing doors of one hour resistance. additional staircases shall be provided at proper places. A system of air inlets shall be provided at basement floor level and smoke outlets at basement ceiling level. Each basement and basement compartment shall have separate smoke outlet duct or ducts. Departmental stores. or an Assembly occupancy. 11. interior finish decoration. It shall also have an arrangement to start it manually.0 Page 215 . high fire loads. making their evacuation in case of fire difficult due to smoke logging and also possible impediments to fire fighting operations. discotheque. storage of flammable oils and gases. Special care to keep escape routes clear. auditorium. Basements Occupancies which are prohibited from being located in basements are either of high risk category. Multi occupancy hazards.Handbook on Building Fire Codes Special care for physically handicapped. The staircase of basements situated at the periphery of the basement to be entered at ground level only from the open air. If the travel distance exceeds the desired level. shops. Indequatc/unserviceable fire protection systems and equipment. banquet hall. Basement shall not be permitted below the ward block of a hospital/ nursing home unless it is fully sprinklered. restaurants etc. Inadequate water supplies. Mechanical extractors shall be designed to permit IITK-GSDMA-Fire 05-V3. Mechanical extractors for smoke venting system from lower basement levels shall also be provided.
there shall be a control room on the entrance floor of the building with communication system (suitable public address system) to all floors and facilities for receiving the message from different floors. The room should be air-conditioned and should have emergency lighting system. Where possible. preferably on ground floor. Details of all floor plans along with the details of fire fighting equipment and installations shall be displayed in the fire control room. IITK-GSDMA-Fire 05-V3. fire dampers shall be provided. Fire Control Room For all buildings 15m in height and above. High rise buildings shall be provided with lightning protection.23. All floors shall be compartmented with area not exceeding 750 m2 by a separation wall with 2 h fire rating. 11.) should be installed in the room. power supply units and the fire protection ancillary panels(for automatic sprinkler system or other fixed fire protection system etc. per hour in case of fire or In ventilating ducts crossing the transformer area or electrical switchboard. The fire staff in charge of the fire control room shall be responsible for maintenance of the various services and the fire fighting equipment It should have an area of 16m2 to 20m2. It should have a mimic panel of the premises protected and details of all the fire protection systems installed. The Control and Indicating Equipment(Control Panel of the AFA system). The fire control room shall also have facilities to detect the fire on any floor through indicator board connection to fire detection and alarm systems on all floors. It should have intercom and direct telephone facilities.0 Page 216 . a direct hot line to local fire brigade should be provided.Handbook on Building Fire Codes 30 air changes distress call.
good house keeping. shall be strictly maintained by the occupants and the owner of the building. 11. House Keeping To eliminate fire hazards. IITK-GSDMA-Fire 05-V3. both inside and outside the building. In many such cases they were rescued from the rooftop helipads using helicopter sorties. keeping things in their places and regular waste disposal. Helipad There had been several cases of major nigh rise building fires when many persons had collected on the roofs of the burning buildings because of non availability of staircases for escape due to smoke accumulation in the escape route.0 Page 217 . Good house keeping reflects good management style and a strong desire to follow fire prevention practices.Handbook on Building Fire Codes 11. Good house keeping boils down to regular upkeep of the premises.24.25.
all those concerned and responsible for enhancement of building fire safety standards continue their untiring effects to mitigate losses of lives and property due to fires. Fire Protection Management Experience has proved that it will be too ambitious and impractical to expect that prevention of fires can be achieved 100% in all types of occupancies and situations. whether existing or hereafter created shall be classified according to the use or the character of occupancy in one of the following groups: Group A Group B Group C Group D Group E Group F Group G Group H Group J Residential Educational Institutional Assembly Business Mercantile Industrial Storage Hazardous IITK-GSDMA-Fire 05-V3. This is what all framers and implementing agencies of national and local level Building Codes and Regulations. as well as the entire building construction community should aspire for. Nevertheless.0 Page 218 . including vagaries of nature and acts of human commission and omission are bound to occur. The best possible way to achieve this laudable objective is to develop an integrated system of balanced fire protection that combines the best of different design features of both active and passive fire protection systems for the buildings.1. 12. when several unpredictable factors.Handbook on Building Fire Codes SECTION 8 .FIRE PROTECTION / FIRE SAFETY MANAGEMENT FOR VARIOUS CLASSES OF OCCUPANCIES 12.2 Classes of Occupancies All buildings.
and obtain necessary clearance for the same from the authorities concerned.Handbook on Building Fire Codes 12.4. 12. 12. Occupancy or Use Group: In the case of mixed occupancy. and hence call for stringent fire prevention and fire protection measures. Cinemas.. extension etc. A building need not necessarly be inhabited. of the building along with necessary drawings. (iii) dangerous to human life or public welfare by reasons of illegal or improper use. occupancy or maintenance. which are buildings having independent occupancies like Shopping Centre. (iv) non-compliance with the provisions of the applicable Codes: (v) significantly damaged by fire or explosion or other natural or man-made cause. Temporary structures need not be construed as buildings.. a Completion Certificate should be countersigned by the designated authorities after inspection. Multiple occupancies. Restaurants etc. simultaneously in one building complex.Unsafe Buildings: Unsafe Buildings are those which are: (i) deficient in means of egress.0 Page 219 . These multiple occupancies contain high fire and life hazard potential. (viii) unsanitary buildings IITK-GSDMA-Fire 05-V3. specifications etc.Change of Occupancies Owner or the occupier shall apply in writing to the local authorities concerned for any alteration. (ii) has a potential hazard from fire or natural or man-made threats. After completion of the work also.5. (vii) buildings having deteriorated structural elements or partially destroyed buildings.3. modification.Multiplexes In many of our major cities. or what are commonly known as "Multiplexes" are coming up. (vi) incomplete buildings for which building permits have expired. the actual occupancy classification of the building or premises will be on the basis of the principal occupancy class.
to a great extent. as individuals and as a group. by keeping the occupants segregated from the harmful effects of fire. make positive contributions to fire and life safety. and therefore. Life Safety also depends to a large extent on the physical and mental characteristics of the occupants. shall be vacated and protect the public by an appropriate fence or such other means as may be necessary. 13.Handbook on Building Fire Codes All unsafe buildings shall be considered to constitute danger to public safety and shall be restored by repairs or demolished or dealt with as otherwise directed by the Authority. Essentially Life Safety implies keeping the harmful effects of fire away from the occupants of the building. Good Fire Safety Management takes note of all these factors and adopts an integrated systems approach so as to achieve optimum results. "Notice shall require the owner or the occupier within a stated time either to complete specified repairs or improvements or to demolish and remove the building or portion thereof. Fire Prevention. General Guidelines for Good Fire Safety Management: Good Fire Safety Management involves and implies Good Life Safety Management also. Staircases/Means of Egress In all cases the leading edges of all treads should be readily visible during both descent and ascent. or vice versa. Means of egress must permit unobstructed travel at all times." The Authority may direct in writing that the building which in his opinion is dangerous. wherever and whatever is possible can also. IITK-GSDMA-Fire 05-V3.0 Page 220 . by adopting methods based on time.1. it will be prudent to bear in mind that no fire prevention strategy can be totally effective. Hand-rails: It is worth noting that handrails are one of the most important components of a staircase. its design should be such as to enable a comfortable grip and also to facilitate the hand to be slid along the rail without encountering obstructions while negotiating the stairs. distance or shielding. However. 13. or has no provision for exit if caught fire.
that the atmoshphere of the smoke proof enclosure will not. airflow control. towers. "The smoke control system should ensure on a 97 percent basis for the geographical location of the building. and with proper ventilation their flow can be safety directed to the outside. 13. and for reducing property damage. during a period of 2 hours. pose special problems with regard to fire and life safety requirements. the following guidance is provided.4. Atrium Buildings: Need special attention with regard to design. it has to be remembered that they may transmit heat by both conduction and radiation.0 Page 221 . including a quantity of air emanating from the fire area that is more than 1 percent of the volume of the stair enclosure" (NFPA 101) 13. including open structures. underground and windowless structures.Handbook on Building Fire Codes One or two steps at a doorway are considered to constitute an accident hazard in emergency use. and buoyancy of smoke can be utilised alone or in combination for smoke management. Products of combustion from a fire get diluted with air in large volume atria.3. Compartmentation. IITK-GSDMA-Fire 05-V3. to minimise the smoke hazard in building fires. and hence call for special considerations in design. pressurisation. Where vision panels and fire windows are provided. and hence should be avoided. fire protection and smoke control. dilution. Special Structures and High-Rise Buildings: Special structures. high-rise buildings. multiplexes etc. Best results are achieved by sound design and engineering judgement and common sense. for assisting firefighting operations. automatic suppression and smoke control. to control smoke movement for assisting easier and more speedy means of egress for occupants.2. either singly or in combination. ventilation. Smoke Control/Smoke Management Smoke Management includes all methods which are resoted to. 13. lay-out and construction aspects. Fire protection in such buildings are usually provided by combination of methods like compartmentation. For ensuring that products of combustion in a fire do not enter a smokeproof stair enclosure.
13. as well as for elimination of use of sub-standard products. products. smoke control systems. containment of hazardous areas etc. controlled interior finishes.5. except in the case of physically challenged(disabled) people who have to be rendered assistance.7. independent schemes for certification/accreditation and registration of installers and maintenance firms will have to be introduced in our country so as to ensure conformity with approved standards and codes. Certification Scheme: Since the fire performance of a system. 13. Provision for movement of disabled persons to areas of safety within the building (Refuge Areas) has also been included in these Regulations. 13. automatic suppression systems. remoteness of exits. illumination and marking of exits.6. These complex occupancies call for a well thought out fire engineering approach to achieve a satisfactory standard of fire and life safety.Handbook on Building Fire Codes Special attention needs to be given on component elements such as concealed combustible spaces. It is the responsibility of the management of the premises to ensure that necessary facilities are provided in the building so that the occupants can evacuate the building in reasonable time in case of fire or other emergency. components or structure is dependent on satisfactory site installation and maintenance.0 Page 222 . fire detection and alarm systems. Provision of barrier free environment for physically challenged people (physically disabled people) has been made mandatory in some of the Building Bye-laws and Development Control Regulations in the country. IITK-GSDMA-Fire 05-V3. enclosure. Means of Escape: The design of a building shall be such that in an emergency the occupants in any part of the building should be able to escape safely without any external assistance.
Where Residential and Non-Residential Occupancies co-exist. shall be of approved classes as per relevant Codes/ standards.Handbook on Building Fire Codes 14. Every Residential occupancy. Interior finishes. The fire escape plans have to be practised periodically by the occupants in the form of 'mock fire drills' so that the evacuation of the occupants in the building can be carried out promptly. including floor finishes in Residential occupancies. including residential homes and flats.. IITK-GSDMA-Fire 05-V3. No dwelling unit of a Residential occupancy shall have its sole means of egress pass through any part of non-Residential occupancy in the same building. Hostels.1. Fire Safety Management as applied to different occupancy groups are discussed below: 14. electrical fire safety etc. In the case of Dormitories. smoothly and in an orderly manner avoiding panic and confusion which can lead to accidents and injuries. should formulate a suitable fire escape plan so that every occupant in the building can promptly and safely evacuate the premises in the event of a fire or any other emergency. the evacuation plans have to be made out with extreme care as more number of occupants are involved. gas fire safety.0 Page 223 . Building Services. Hotels etc. including lifts/escalators shall be of standard approved types as per relevant Codes/Standards. Residential Buildings(Group A) Good Fire Safety Management in homes call for strict and constant observance of all the common home fire safety rules for kitchen fire safety. extreme care has to be taken in the design and construction of the premises so as to ensure that all essential fire and life safety requirements as per Codes are incorporated in the building. It has to be ensured that the exits and stairways of the building are always kept clear of all obstructions or hazardous materials.
transformers etc. 14. having fire and explosion hazards. fire resistance rating. may be of Type II or Type III construction as per IS 1642. high-pressure boilers. IITK-GSDMA-Fire 05-V3. All such semi-permenant buildings shall be restricted to ground and one upper floor only. fire resistance. fire resistance. shall be fixed to an outside wall or to a duct of noncombustible material. shall not be allowed for housing educational institutions. Kitchen exhaust ducts are hazardous since they convey hot and flammable gases and vapours. and the floor area not exceeding 1000 m2 on each floor. shall not be located directly under or adjacent to exits. Educational Buildings (Group-B) Educational occupancy is distinguished from Assembly occupancy in that in the former the same occupants are regularly present. as well as temporary structures. while internal / non-load bearing walls shall have 2 hrs. they must have the required fire resistance also. Flammable liquids for household purposes shall be kept in tightly stoppered or sealed containers.2. and they are subject to discipline and control. All educational buildings not of permanent nature. All educational buildings of permanent nature shall be of Type I construction having external shell and load bearing elements of 4 hrs.0 Page 224 . No stove or combustion heater shall be located directly under or immediately at the foot of stairs or otherwise so located as to block escape.'Fire door-Keep closed' In addition. All kitchen exhaust fans. All outdoor antennae shall be properly grounded and protected from lightning. Type IV construction.Handbook on Building Fire Codes Rooms containing A/C plants. Walls of enclosure for such rooms shall have minimum 4 hrs. such as tents or with thatched construction. which leads directly to the outside. Particular care has to be taken to avoid storage of low flash point flammable liquids like petrol in residential accommodation. Doors leading to rooms in which flammable liquids are stored or used shall be posted with a sign on each side of the door in 50mm high block letters stating .
lift. shall have minimum two staircases of enclosed type. The main staircase and external staircase shall be continuous from ground floor to the terrace level. The width of staircases shall not be less than 1. IITK-GSDMA-Fire 05-V3.Handbook on Building Fire Codes Basement. Every clasroom with a capacity of 45 persons or more should have minimum two door exits. laboratories.0 Page 225 .5 m for building up to a height of 30 m. Internal stairs shall be constructed of non-combustible materials throughout. Emergency lighting in accordance with approved standards must be provided for all interior stairs and corridors and normally occupied areas. libraries or for assembly halls. The treads shall be constructed and maintained properly so as to avoid slipping during use. Maximum height of riser shall not be more than 150 mm and number shall be limited to 15 per flight. NO exit doorway shall be less than 1m. No combustible material (interior finish) shall be used for decoration/wall panelling in the staircase. Educational buildings above 30 m in height are not permitted. should not be used for classrooms. and 15 m or more in height. store or other fire risk shall open directly into the staircases. The doors shall open inwardly wherever the doors lead to corridors or open on landings leading to flight of stairs. All internal staircases. The occupant load of educational buildings or any individual story or section for determining the exits required shall be not less than one person per 4m2 of net area. The height of door shall not be less than 2m. Any building having area more than 500 m2 on each floor. lobbies and corridors should be adequately ventilated and illuminated. There shall be at least two exits available from every floor area. Minimum width of treads for stairs shall not be less than 300 mm. No living space. if constructed.
latest version. It shall be of size not less than 0. and to remain on continuous operation for a minimum duration of 1 hour and 30 minutes. 'Fire Safety in Educational Institutions-Code of Practice' should be complied with for all Educational Buildings. IITK-GSDMA-Fire 05-V3. Doors in fire resistant walls shall be so installed that these may normally be kept in open position. Corridor door openings in smoke barriers shall be not less than 1500 mm in width.5 x 0. ethyl alcohol. and near the floor for heavier than air vapours like LPG. which should be designed to come on within one second of the failure of the normal lighting supply. Ventilators should be provided near cieling level for lighter than air vapours. which should conform to approved standards. etc shall be allowed to be handled or stored. Fire Protection and Life Safety requirements as stipulated in National Building Code Part 4.5 m. Bare minimum quantities of flammable materials such as chloroform. All exit marking signs shall be prominently indicated showing the way to the escape route. Proper care shall be taken in providing electrical installations in such rooms. and the same shall be illuminated by electric light connected to corridor/staircase circuits along with emergency lighting.0 Page 226 . Provision shall also be made for double swing single/double leaf type doors. care has to be taken to ensure that no wall opening or window opens on to or close to an external staircase. as well as IS 14435 1997. If external stairs are provided. but will close automatically when required. shall be provided with a suitably designed exhaust ventilation system. Any room in which volatile flammable substances are used or stored. spirit. No combustible material of any kind shall be stored or used in any building or section thereof.Handbook on Building Fire Codes Floor indication boards shall be prominently indicated on the wall facing the staircases near to the landing.
away from the main building where class rooms are located. Laboratories in the Educational Institutions shall comply with all the fire safety measures as stipulated in relevant standards. Educational Buildings having height 15m or more should comply with fire protection and life safety norms for high rise buildings as prescribed in NBC Part 4. 'Code of Safety for Chemical Laboratories'.0 Page 227 . Emergency Plan should be made by all Educational Institutions. where provided in Educational Buildings should have the fire protection arrangements as prescribed in IS-12456-1988. and evacuation drills should be organised at regular intervals. where carried out in Schools. Installation and Maintenance of First Aid Fire Extinguishers' should be installed in all Educational Buildings. in a detached building. and the ovens/burners should be kept at an elevated surface compared to the cylinders. proper safety measures have to be exercised in the handling of the connected equipment. should be done at a safe place. which should be not less than once a quarter.Handbook on Building Fire Codes Portable fire extinguishers as per scales recommended in IS 2190-1992. They and selected Senior Students should also be trained in the use of first aid fire fighting equipment in case of fire emergency. Educational Institutions having auditorium should have fire protection and means of exit arrangements as required for similar capacity Assembly occupancies. like IS 4209-1987. IITK-GSDMA-Fire 05-V3. If gas or electricity is used for the kitchen. Teachers and other staff of the Educational Institutions should be sensitised to their responsibilities for the safety and well being of the students. 'Code of Practice for fire protection of electronic data processing installations'. Computer Rooms. 'Code of Practice for Selection. Cooking of food.
14. especially since freedom of movement of the inmates is generally restricted with limited or ordinarily blocked exits.Handbook on Building Fire Codes Along with the evacuation drills. and hence need special aptitude and training for effecting timely and orderly evacuation of occupants. life hazard potential is quite substantial. by and large. particularly those with impaired physical and mental capacities.1. As against Health Care Facilities. are adequately provided and properly maintained. presumably because there had been an increasing number of such wide ranging occupancies also. Institutional Buildings (Group-C) 14. IITK-GSDMA-Fire 05-V3. so that the students from their very young age will be suitably trained in inculcating safety habits. needs assitance. The staff employed in these occupancies have a major role to play in the life safety of occupants. As compared to normal Residential occupancies. which fall under the Group. These evacuation drills/training have to be practised periodically. provide personal care services of occupants. Since the ultimate responsibility for the life safety of the inmates of the Detention. General Fires in this type of occupancy had shown a rising trend in the last two decades.3. A Systems Approach is necessary so that the fire safety as well as security requirements for such occupancies are controlled harmoniously without adopting contradictory concepts. Asylums and such other Institutional occupancies rests with the Management of such occupancies. it will be desirable to organise short duration special training programmes on any safety subject. Institutional occupancies. Old-age Homes. Correctional. other categories of building covered by this Group such as Jails. including the fire protection facilities..0 Page 228 . Prisons. However. Day Care facilities etc. Orphanages. and in several cases evacuation of occupants. atleast once in every three months. they have to ensure that all basic standard requirements of fire and life safety in the design and construction of the buildings. fall in the ordinary hazard classification with hardly any fire load density.3.
Halothane. Divinyl Ether. Ethyl Chloride etc. installation. All stipulated safety precautions should be observed in the storage and handling of various types of gas cylinders which are usually found in such occupancies. testing.0 Page 229 .. Similarly. Wherever clinical procedures are performed like operation rooms. IITK-GSDMA-Fire 05-V3. Enfluorane.Handbook on Building Fire Codes 14. delivery rooms etc.3. Trichloroethylene. It will be desirable to maintain slight positive pressure in such areas to prevent infiltration of contaminated air into such sensitive areas. Methoxyfluorane. The floors of operation rooms. As a general guidance.2. operation and maintenance of these systems. A resistance not exceeding 50 mega ohms is generally sufficient to prevent accumulation of dangerous electrical charges. special mechanical ventilation arrangements are required. The following anaesthetic agents are considered non-flammable during conditions of clinical use: Chloroform. Specific precautions are to be taken to protect oxygen cylinders. the undermentioned anaesthetic agents are considered flammable during conditions of clinical use: Cyclopropane. Full cylinders shall be stored/kept segregated from empty cylinders. Fire Prevention/Fire Safety Measures in Health Care Facilities Potential fire and explosion hazards associated with medical gas piping systems shall be taken into account in the design. containers and associated equipment from abnormal mechanical shock and heat. Ethyl Ether. Personnel entering such hazardous areas shall wear shoes having soles and heels of conductive rubber. all necessary precautions should be observed in the storage and handling of bulk cryogenic liquid systems (generally liquid oxygen). Nitrous Oxide. anaesthetezing locations and such other rooms/locations and contiguous areas where hazardous gases/vapours are likely to be present should have conductive floors to equalise/dissipate possible static charges. Ethylene.
separated or protected as to avoid any undue danger to the occupants of the place of assembly from a fire originating in the other occupancy or smoke therefrom. and are not recommended to be located in the basements. fire safety. which may contain various hazardous materials. However. 1998 refers).Handbook on Building Fire Codes While plastic containers are preferred to glass containers to avoid breakage problems. Assembly Buildings (Group-D) Mixed Occupancies are predominantly life hazard occupancies. attendants. It is. It is essential that core personnel employed in hospital facilities like doctors. In any case. have to be scrupulously complied with(Bio-medical Waste (Management and Handling) Rules. The relevant pollution control rules regarding the safe disposal of hospital wastes. in case of emergencies. necessary that the fire protection measures incorporated and maintained for such occupancies should be of the highest standards so as to ensure maximum life safety opportunities for the occupants. etc.0 Page 230 . All rooms or areas used for storage of any combustible materials or equipment. IITK-GSDMA-Fire 05-V3. it has to be remembered that life safety of all the patient occupants in health care facilities cannot be adequately assured by evacuation procedures alone. shall be so located. Thy shall be located away from staircases. refurbishing. Places of assembly in buildings of other occupancy. care has to be exercised in the choice of plastic containers in their compatibility with the liquid to be contained. aides. repair or similar purposes shall be effectively cut off from assembly areas.4. nurses. evacuation procedures. Canteens in auditoriums pose substantial fire and life safety hazards. or for painting. To ensure this. 14. it will be necessary for provision of fire barriers (fire resistant seperating walls) also to segregate the fire hazardous areas from Assembly areas. they must be sprinklered. Besides installation of sprinklers. therefore. etc. regular instructional programmes and fire drills should be conducted and records maintained. wards. shall be indoctrinated in all aspects of fire prevention.
and when so closed. and provided with adequate vents to the outside air. IITK-GSDMA-Fire 05-V3. The proscenium wall of every theatre using movable scenery or decorations shall have exclusive of the proscenium opening. doctors.0 Page 231 . operable from the stage floor by hand. 14. The handling and use of gasoline. and also opening by fusible links or some other approved automatic heat/smoke actuated device. Subdivision E-4: Telephone exchanges. Subdivision E-3: Computer installations.5. like offices of architects. to give a free opening equal to at least one-eighth the area of the floor of the stage.1. fuel oil and other flammable liquids shall not be permitted. The decoration of places of assembly shall be of non-flammable materials. engineers. each not to exceed 2m2 and fitted with self-closing fire resistant doors. The stage roof of every theatre shall have a ventilator or ventilators in or above it.Handbook on Building Fire Codes Rooms containing equipments subject to possible explosion shall be effectively cut off from other parts of the building. research establishments.Business Buildings (Group E) 14. The curtain shall have an emergency closing device capable of causing the the curtain to close without the use of power. Subdivision E-2: Laboratories. Decoration materials and stage settings of combustible nature have been the cause of several theatre fires. professional establishments. lawyers and police stations. Fabrics and papers used for such purposes shall be treated with an effective flame retardant material.5. banks. it shall be reasonably tight against the passage of smoke. Business buildings shall be further sub-classified as follows: Subdivision E-1: Offices. Stage settings made of combustible materials shall likewise be treated with fire retardant materials of Class 1 flame spread. which have resulted in total losses. not more than two openings entering the stage. libraries and test houses.
Exits shall be so located that the travel distance on the floor shall not exceed 30m. 14. Due to the under mentioned reasons. furnishings etc. Individual floors shall be prominently indicated on the wall facing the staircases as well as lift landings.3. All requirements of Emergency and Escape Lighting as per Code should be implemened. Exit doors shall not open immediately upon a flight of stairs. The ocupant load for business building should be 10m 2 / person. No exit doorway shall be less than 1m in width.2. Internal staircases shall be constructed of non-combustible material and should be protected staircases. Materials used for interior finish. lifts. 60 for ramps and 75 for doors. In case of high rise buildings. All means of exit including staircases. all necessary fire protection as well as means of exit requirements as per NBC Part IV should be incorporated. The ocupants per unit exit width should be 50 for stairways.5. the life safety requirements in business buildings amount to early alerting the occupants in case of fire or any other emergency. Incase of high rise buildings. They should be of fire resistant construction.5. No gas piping shall be laid in the stairway. 14. The fire protection and the means of escape requirements for business buildings are as given below: Business Buildings have no restrictions in height. and providing adequate facilities for escape / evacuation so as to ensure life safety of the occupants considering the type and nature of the building: IITK-GSDMA-Fire 05-V3.0 Page 232 .V. No part of the building should be utilised for storage of flammable liquids or hazardous materials. should be of Class-1 flame spread. fire lifts should be provided as per Code.Handbook on Building Fire Codes Subdivision E-5: Broadcasting stations and T. lobbies and corridors shall be adequately ventilated and lighted. Stations.
Mercantile Buildings(Group F) 14. movement. Occupants are generally expected to be alert. and thus the life hazard potential in these buildings. it is necessary that the Business buildings. Assistance or special evacuation help will have to be rendered to physically challenged (disabled) people. or Hazardous occupancies. and larger Shopping Malls/Centres. Mercantile buildings form 3 sub-divisions: Sub division F-1: Shops. is quite high and. accommodation as well as for the means of exit requirements for physically challenged people. Departmental Stores. 14. Markets. therefore.4. Occupants are expected to be familiar with the lay out and exits of the building. small retail outlets etc. 14. phased evacuation may have to be adopted. with area up to 500 m2.1. especially those with larger areas and more floors. in which case. the occupant load.Handbook on Building Fire Codes Building remains occupied generally only during day time. storage areas.5. Similarly. Sub division F-2: --do-. also have to be adequately incorporated in the buildings. But. majority of the occupants are expected to be physically capable of self-evacuation in case of fire or other emergency. the Code as well as mandatory special design and construction requirements for the access. Generally.6. IITK-GSDMA-Fire 05-V3. kitchens.with area exceeding 500m2. which together can constitute high fire load. As per NBC Part 4.0 Page 233 . auditoriums. car parking facilities. Other factors: The fire load in Business buildings is defenitely lower than Storage. must have the stipulated scales of fire protection requirements as per Codes.6. Department Stores and Super-markets contain different kinds of merchandise. Stores. Total evacuation may be difficult in case of a high rise building fire. The designer and the Code oficials will have to undertake a pre-evaluation of life safety as well as fire protection systems required for Business buildings taking into consideration factors like the need for support services for such premises like cafetarias. Sub division F-3: Underground Shopping centres.
14. 14. 14. these buildings may be multi-storeyed ones. with customer movement patterns permitting both vertical and horizontal movements. that a lot of careful thought and planning have to be addressed in the design and construction of the buildings. IITK-GSDMA-Fire 05-V3. Apart from 'over-roof' mercantile operations.6. particularly the life safety concerns. along with retail outlets also.6. like mandatory sprinkler protection. Their peculiar design.6. Storeyed buildings have open stairs and sometimes escalators also. where bulk quantities of textile materials are stored.Handbook on Building Fire Codes Generally.3. such complexes also shall scrupulously comply with all the fire and life safety protection requirements as stipulated in the Codes. These below grade shop complexes are quite fire hazardous and warrant due fire protection messures. all Building Codes should address the problems relating to covered mall shopping centres also.5. as well as from the world-wide experience gained in the past through major fires in Department stores. mercantile units o function in basements and sub basements levels also in our cities. the hazards are much more multifarious with more serious evacuation problems. and the fire protection and means of exit arrangements required to be incorporated in such buildings must also be of the highest standards. shall be considered under Hazardous buildings. especially in big Departmental Stores. 14.2 In some of the cities in India (like Surat for instance) there are huge multi-storey (high-rise) complexes such as Textile Market. 14. It follows from the above. layout and high fire density. along with a large number of floating customer population as well as staff.6. Hazardous areas shall be segregated. Mixed Occupancies of this nature are quite hazardous and quite a few fire incidents had occurred in different cities / towns in India and abroad in such premises causing fatalities. Stringent Code implementation is a must in such occupancies.0 Page 234 . all in combination virtually make these premises highly vulnerable from fire and life safety point of view. The high fire hazard potential in such complexes necessarly call for high standards of fire protection also. Occupancies where goods of a highly hazardous nature are predominant.4. Apart from what has already been stated.6. In the case of Underground Shopping Complexes.6. Therefore.
Handbook on Building Fire Codes 14. Guidance with regard to the classification of Industrial Buildings into low. as well as the innumerable types of hazardous materials handled and processed in these promises. The hazards involved in industrial occupancies vary greatly and.7.1. moderate and high hazard classes and the types of industrial buildings coming under this subdivisions can be obtained from Annex-B to Part 4. and from which pistonous fumes or explosions are also likely.2.0 Page 235 . The large number of such occupancies which abound in urban and rural areas in the country. and G-3 classes of industries in one building.7.7. and may give off large volumes of smoke. IITK-GSDMA-Fire 05-V3. Subdivision G-3: Buildings used for housing high hazard industries. Subdivision G-2: Buildings used for moderate hazard industries in which there are possibilities of fires which may burn with moderate rapidity. and human factors are generally responsible for such heavy losses. which come under this Group of Occupancies. NBC. 14. and the fire protection requirements which are commensurate with high hazard class industry will have to be provided. Industrial Buildings (Group G) 14. which are liable to give rise to fires which will burn with extreme rapidity. In case of mixed occupancies of G-1.General Global statistics bear out the fact that fires and explosions in industrial and manufacturing facilities. account for the major portion of direct material losses as well as indirect losses (such as production losses) in a country. therefore. G-2. Subdivisions: Buildings under this Group are subdivided according to hazard categories: Subdivision G-1: Buildings used for low hazard industries in which the contents are of low combustibility. an integrated approach has to be followed in the matter of provision of adequate fire and life safety requirements for such premises. where no partition walls are provided between the various classes of occupancies. In the matter of loss of lives also this Occupancy Group is one among the front ranking Groups like Assembly. the entire building will have to be considered as a G-3 premises.
spark from tools can be avoided by use of non-sparking tools.. While safety from electrical sparks can be achieved by safe electrical equipment/apparatus as already mentioned. apart from complying with the requirements specified in relevant Parts of NBC as well as local Codes/Bye-laws/Regulations regarding design. the slightest spark created by the operation of electrical equipment like switches or spark producing tools(friction sparks) can give rise to fire or explosion. have to comply with the relevant provisions of the same. issued by Govt. rate of fire spread. 14. are given in various Schedules under the Manufacture. siting. Whenever flammable vapours/ gases are present within their flammable limits. pollution-prone etc. In appropriate cases. Off-site Emergency Plan etc.3.7.Handbook on Building Fire Codes Factors to be considered for evaluation of life safety risks are materials used for interior finish. Hazardous. IITK-GSDMA-Fire 05-V3. for starting. potential ignition sources. Property protection follows employees evacuation.) will also be necessary. of the industry. operating etc. Industrial occupancies which come under the purview of Industrial legislation of the Central / State Government. and construction of the buildings and for incorporation of the fire and life safety requirements in the buildings. If Petroleum liquids are stored or handled at temperatures at or above their flash point. of India. fire load and smoke generation. evaluation of toxic fumes. On-site Emergency Plan. industries. or 30m from equipment handling flammable gases. burn rate.0 Page 236 . Safety Data Sheet. as designated by the authorised legislation. Storage and Import of Hazardous Chemicals Rules 1989. including the details of information to be furnished on various documents/forms (to be submitted to appropriate authorities) like Safety Report. they should be treated with extreme caution (as for class-1 flammable liquids). Hazardous area normally covers an area extending upto 15m from equipment handling flammable/combustible liquids. The details of these requirements. clearance from the Chief Controllor of Explosives (Explosives Dept. are required to formulate and submit their On-site and Off-site Emergency Plans to the concerned authorities on specified time schedules.
and the fire hazard potential of products (storage. The choice of the fire protection system shall depend onthe nature of the risk to be covered at the planning and design stages. suppress and control damage from explosions are available and must be utilized judiiciously.Handbook on Building Fire Codes Electricity generation can be done from conventional sources using coal. Industrial buildings of low and moderate hazard are permitted only up to 18 m height. Flammable dust. In case of any fire outbreak in electricity generating and distribution stations. handling and transportation risks of different chemicals).0 Page 237 . Specialised equipments designed to detect. construction. The primary factors to be considered are building design. IITK-GSDMA-Fire 05-V3. Since explosions are probably the cause for most destructive industrial accidents in terms of life and property loss. vapours. they require special attention. Apart from above. but several other industries and enterprises depending upon them for power will also face shut down. Every detail with regard to maintenance of adequate safeguards against likely fire and explosion hazards in the entire premises will have to be taken care of. A carefully designed system is needed to ensure life safety from explosive forces. oil. It is important that building design. All high hazard industrial occupancies shall have explosion venting for any area subject to explosion hazard. Each one of the types have their own fire hazards which call for appropriate fire protection measures as stipulated in relevant Codes. nature. fire and explosion hazards potential of processes involved. Hydro-power and Nuclear power generation also are employed. such occuapncies may not only completely disrupt the life of the community as a whole. fire load potential and quantity of raw materials. mist or gas presents an explosion hazard. Industrial buildings of high hazard are permitted only upto 15 min height. process lay out and the fire protection systems allow for safe and prompt occupant egress in the event of fire or explosion. gas turbines or diesel generating sets.
with anti-freeze additives. General Storage occupancies can also be classified as low. Storage buildings (Grouip H) 14. Materials in storage may also contain highly flammable liquids and gases. are not only highly combustible but also generate thick highly toxic smoke and gases which can prove a life hazard also. packing materials etc. dunnage. Modern development in material handling techniques have led to adoption of high-stack storage areas. it will be necessary to supplement the sprinkler system with other measures like hydrant system. Properly installed and maintained automatic sprinkler systems provide a highly effective protection against life and property losses in Storage occupancies. which are commonly used as insulation materials. which are primarily used for extended storage of perishables like food products.8. care has to be taken to ensure that sprinkler system design is compatible with the materials stored and with high-stack storages. fire extingishers etc. Special storage arrangements are adopted for flammable liquids like storage tanks(large cylindrical/horizontal storage tanks in Tank Farms as found in Oil Installations).0 Page 238 .8. Also. hose-reels. However. have also their peculiar fire hazards even though the inside temperatures may be as low as-40o C. Besides. The fire protection requirements for such storage occupancies are given in relevant Standards and Codes. A well designed automatic sprinkler system. Cold Storage warehouses. it can be a combination of these also. is the ideal primary fire protection measure for such premises. They are not covered under Building Codes. going up to 30 m height also. and large cylindrical /horizontal/Spherical tanks/ containers etc for gases. the refrigerant gases can also pose toxic and flammable hazards. ordinary or high hazard depending on the fire load of the materials stored.Handbook on Building Fire Codes 14. Polyurethane foams or polystyrene foams.1. IITK-GSDMA-Fire 05-V3. The fire hazards primarily arise form the use of combustible materials like cork or expanded foam used for insulation. In many cases.
Bad house keeping. Level of even essential fire protection arrangements remain far below the stipulated minimum standards. in cold storages. expanded foam insulations etc. Large amounts of packing materials (including plastic expanded foam). The premises remain unoccupied most of the time. Careless smoking. IITK-GSDMA-Fire 05-V3. straw etc. paper.). it remains undetected for some time. Electrical faults (bad maintenance). Storage of flammable stores in 'bonded goods' area. the fire would have become a major one making fire fighting operations prolonged and difficult. which are invariably present in warehouses.8.0 Page 239 .2. which should be regularly practised. rendering the fire fighting operations difficult. Storage of hazardous cargo also along with other stores without proper segregation. By the time fire brigade is sommoned and arrives at the scene. within the building. and by then it assumes serious proportions. and if a fire breaks out. or the existing fire protection systems fail to operate due to bad maintenance. 14. External sparks (from moving locos etc. with few and inadequate aisles between stacks. Spontaneous ignition (of oil/paint smeared cotton waste thrown underneath the stacks after cleaning/maintenance work). Welding /cutting. Use of naked lights/ heaters/signs inside the building. spray painting etc.Handbook on Building Fire Codes All Storage occupancies should formulate an appropriate and efficient Emergency Plan. Use of highly combustible materials like cork. Large number of fires occur in storage occupancy group mainly becaue of the following reasons: They have the highest values of fire load density (up to 500 kg/m2). The godwowns are invariably packed up to cieling /roof level.
Failure to carry out regular closing hour checks.1989.1. handling. IITK-GSDMA-Fire 05-V3. Each building shall be provided with a power driven fan exhaust system of ventilation which shall be arranged and operated so as to produce a complete change of air in each room every 3 minutes. storage. The various central legislation governing the manufacture.0 Page 240 .9.9. General NBC Part 4 explains in detail the purposes for which this group of buildings are utilised. 1989. Storage and Import of Hazardous Chemicals Rules. and hence buildings storing.Handbook on Building Fire Codes Badly maintained or over . Hazardous materials are materials which may be explosive. Hazardous Buildings (Group J) 14. flammable. manufacturing or processing hazardous materials are placed in this group of buildings posing the highest hazard. Hazardous buildings are used for storage. 1986. Environment (Protection) Rules. corrosive or otherwise harmful. Manufacture. handling etc.taxed sprinkler systems. 14. generally in substantial quantities. Fire and life safety deals with protection of both lives and property. 14.3. handling. 14. poisonous/toxic.9. Forklift trucks etc. and likely to cause death or injury to persons / living beings. manufacturing and processing of a wide range of hazardous materials. Arson/Sabotage.9.2. of the hazardous materials are as given below: Environment (Protection) Act. Careless handling of mechanical handling equipment like EOT cranes. 1986. Other Points: All openings in exterior walls made for utility services shall be protected by fire stop assemblies. Hazardous Wastes (Management and Handling) Rules.
Certain dusts. Such valve location should also be conspicuously marked on external walls for locating them readily in case of emergency. IITK-GSDMA-Fire 05-V3.Handbook on Building Fire Codes Breakage of gas line due to heat of fire can be disastrous.0 Page 241 . Equipment or machinery which generates or emits combustible or explosive dust or fibers shall be provided with an adequate exhaust system. Approaching gas control valves in a room on fire becomes dangerous. besides being environmental hazard. Any room in which volatile flammable substances are used or stored should be enclosed in a flameproof enclosure. Each building where gas is employed for any purpose shall be provided with an approved outside gas shut-off valve conspicuously marked. can cause dangerous explosions if they are allowed to mix with air so as to reach their explosive limit. Use of explosion suppression system helps tackling explosion at early stage. Control Valve should be located outside the building.
The present day society can never even imagine of enforcing such barbaric laws of retaliation. the architect is to be put to death. the minimum Code requiements must be met. means of egress. IITK-GSDMA-Fire 05-V3. or at least minimisation of risk) to people or property.2.0 Page 242 . Nevertheless. Safety is often reckoned as the opposite of risk. these regulations evolved into Codes and Standards developed by assigned Committees / Bodies responsible for community safety. Features covered include structural design. and generally represent a compromise between optimum safety and economic feasibilty.AN OVERVIEW 15. fire protection.BUILDING CODES AND REGULATIONS . if the son of the owner loses his life". in addition to the high levels of accountability and penalty which was being atached to Code violations. will ever be remembered for his 'oft-quoted' stringent decree from his Code which ran as follows: "In the case of collapse of a defective building. 15. who ruled over Babylonea some 3500 years ago. and the architect's son. Risk can never be eliminated. Role of Codes in Community A Building Code is a law that sets forth minimum requirements for design and construction of buildings and structures.Handbook on Building Fire Codes SECTION 9 . sanitation. Although builders and owners often established their own requirements. King Hammurabi.1. if the owner is killed by accident. and hence safety can never be absolute. this historic anecdote gives an insight into the extreme importance and value the old civilisations used to bestow on human as well as building safety. Early Building Codes All through the history of mankind. Greater safety means less risk (elimination. light. These minimum requirements are established to protect the health and safety of society. and interior finish. there have been Building Regulations for safeguarding against fires and fire spread. Over the years.
The designer and builder are. and how components should be assembled.(ii)Performance Codes. The first version of NBC was published in 1970.0 Page 243 . local authorities and other construction agencies. both active and passive. thus. if they can be proved as adequate. 15.Role of Standards in Building Codes Several of the provisions found in Building Codes are based on the standards published by nationally recognised organisations. the fire protection measures incorporated for the buildng. Performance oriented Building Codes still embody a fair amount of specification .type requirements. The most extensive use of the standards is their adoption into the Building Code by reference. The impact of Building Codes on Fire Protection and Prevention resulted in the establishmen of height and area criteria. how large(or small)the building can be. which detailed the objective to be met. also provide reasonable safety from the effects of fire. IITK-GSDMA-Fire 05-V3. The architectural design of a building has a significant effect on its fire safety characteristics. allowed freedom in selecting constructional methods and materials as long as the performance criteria can be met. departments. Building Codes and Fire Protection are two sides of the same coin.4. The promulgation of modern Building Codes began with disastrous fire incidents which had taken place at the turn of the century. Thus. but the provision exists for substitution of alternate methods and maerials. (i) Specification Codes which spell out in detail what materials can be used. thus keeping the Building Codes to a workable size.3. which serve to alleviate the loss of life and property. and establish criteria for determining if the objective has been achieved. it is understandable that Building Codes and Fire Protection are partners in alleviating the loss of life and property. and eliminating dupication of effort. 15. Similarly.Handbook on Building Fire Codes There are two types of Building Codes.National Building Code It was as a sequel to the recommendations of a Panel ofExperts contituted by the Planning Commission in 1965 that Bureau of Indian Standards(the Indian Sandards Institution)was entrusted with the task of preparation of a National Building Code to bring in uniformity in the builing regulaions throughout the country for adoption by Govt.
the nature of occupancy and the activities pursued by the occupants of the building must also be taken into consideration. Govt.5. Part IV prescribes only the basic minimum requirements for achieving fire and life safety in buildngs. 15. The Convenor for IITK-GSDMA-Fire 05-V3. A vigorous implementation drive was taken up by the BIS(ISI) as well as the Fire Advisor's Office in the Ministry of Home Affairs to disseminate and propagate the contents for adoption by all concerned. of which Part IV deals with Fire Protection. As per a dicision taken by the BIS last year the ten Parts of the NBC Part-IV are undergoing revision at present. and so framed to make the adoption process easy. The panel worked under the jurisdiction of Fire Safety Sectional Committee CED-36. of which Shri J.7.6. and nothing in the Code prohibits better type of building construction. 15. Vakil. of India. 15. of India as Convener of the Panel. ex-Fire Advisor. General Manager.N. but for periodical review of the existing regulatory provisions at various levels also. Consequent to receipt of several comments and useful suggestions for modifications and additions to the various clauses in the Code.8. more exits. A point worth mentioning here is that while assessing the extent of fire hazards in a building. who is also one of the two fire experts co-opted as a Consultant for this Project under GSDMA) for revision of Part IV. Part IV Fire and life safety consists of 17 Sections and 7 Appendices. Tariff Advisory committee. Consequent to receipt of several comments and observations from various agencies.B.0 Page 244 . The provisions of the Code are formulated on the information contained in various Indian Standards woven into a continuous and cogent pattern relevant to each Part. 15. a revised version of the entire NBC was pulished in 1983 which is currently in vogue now. do exist to the effect that the provisions of the NBC serve as a model for adoption by governmental departments local authority and other implementing organisations. Menon. was the Chairman. ex-Asst. the other fire expert co-opted as a Consultant for this Project. The NBC has ten Parts.Handbook on Building Fire Codes 15. Govt . or other conditions that are prescribed in the Code. Instructions from the Central Govt. the BIS had instituted a Panel of Experts in 1995 (with Shri G. Action Committees were set up by various state and local bodies not only for implementation of the Code.9.
arrangement and use of buildings. but is also the most cost effective approach. transportation and storage systems etc. it is mentioned that the Commentary and Handbook have been prepared on the basis of the last Draft Revision of NBC Part-IV which was circulated as well as the decisions taken in the relevant Committee Meeting. and of the behaviour of people in fire. Reduction of potential damage by proper design. However. installation. in the advanced countries like U.0 Page 245 . Europe etc. Design. suppression.. It is not only beneficial from fire safety point of view. Dedicated fire safety regulations and controls got formalised only since the last century.Handbook on Building Fire Codes the Panel for revision of Part IV is Shri.K.S. 15. property and the environment from the destructive effects of fire. there has been an increasing trend for addressing the fire safety of buildings and structures through the recently developed discipline of Fire Safety Engineering. of fire detection. IITK-GSDMA-Fire 05-V3.K. structures. in order to protect people. These objectives are achieved for building fire safety by a range of processes including: Assesement of the fire hazards and its effects. U. 15. Dheri. It can be defined as the application of scientific and engineering principles based on an understadning of fire. For major building projects and for specialised developments or where there are very unusual or multiple fire hazards. In this context. fire-related communications and equipment. who is a well-known expert in fire protection field. ex-Chief Fire Officer Delhi Fire Service. construction.11.S.A. a fire safety engineering approach (or fire engineering approach) is necessary... initially reactive legislation followed particularly devastating fires like the Great Fire of London in 1666. International trends in Building Codes In the west. materials. Direction and Control of appropriate equipment and manpower in fire-fighting and rescue operations. control.10. Fixing the parameters for appropriate level of evaluation for provision of optimum fire prevention and protection measures. maintenance etc. Part IV is still under revision. indus trial processes.
it will be desirable to amend the existing Building Codes / Bye-laws Development Control Rules to include the relevant provisions from a Govt Notification dated 21st March 2001 issued by Ministry of Urban Development. Fire Safety Engineering and Indian Scenario In a country like India. owners and statutory authorities have to be made accountable for inadequate provision or untimely failure of the fire protection measures in buildings.0 Page 246 . Regulations should firmly place the responsibility for provision and maintenance of fire protection facilities in buildings on owners and occupants.compliance with relevant Codes. where enforcement of legislative controls are lacking.12. The different parties involved in the construction of a building like architects. IITK-GSDMA-Fire 05-V3. and where Code violations are more common than compliance. which makes the players in the building industry accountable and liable for any negligence on their part for non . In this context. structural engineers construction engineers. contractors. due care has to be taken to ensure that the new approach does not reduce the level of fire and life safety standards. of India.Handbook on Building Fire Codes 15. promoters. Govt.
0 Page 247 .A IITK-GSDMA-Fire 05-V3.Handbook on Building Fire Codes Annex .
1990 Merchant Shipping (Fire Fighting Appliances) Rules. Factories Act 1948 (as amended in 1987) State Factories Rules (in various States) Petroleum Act. 28. 1988 (As amended in 1994) Central Motor Vehicles Rules. 1986 Delhi Fire Prevention & Fire Safety Rules. 7. 3. 1952 Oil Mines Regulations. 2. 1989 Model Fire Service Bill (As circulated to State Governments in 1958) State Fire Service Acts and Rules (In various States) Delhi Fire Prevention & Fire Safety Act. 1934 Petroleum Rules. 1986 Environment (Protection) Rules. Preparedness and Response) Rules. 26. 13. 1983 Gas Cylinder Rules. 1989 Cinematograph Act. 8. 1996 Manufacture.1987 IITK-GSDMA-Fire 05-V3. 1952 (With State Acts and Rules) Public Liability Insurance Act. 14. 9. 12. 1958 Merchant Shipping (Fire Fighting Appliances) Rules. 17. 19. 1884 Explosive Substances Act. 15.B LEGISLATION RELATING TO FIRE SAFETY / FIRE PROTECTION IN INDIA 1. 24.Handbook on Building Fire Codes Annex . 11. 25. 20. 1984 Environment (Protection) Act. 1981 Carbide of Calcium Rules. 5. 1908 Explosive Rules. 4. 1969 Hazardous Wastes (Management and Handling) Rules\. 1976 Indian Explosives Act. 1981 Merchant Shipping Act. 22. 1989 Chemical Accidents (Emergency Planning. 1986 Air (Prevention and Control of Pollution) Act. 21. 1937 Indian Mines Act. 1991 Motor Vehicles Act. 10. 27. 18. 23. 6. Storage and Import of Hazardous Chemicals Rules. 16.0 Page 248 .
Handbook on Building Fire Codes Annex .C LIST OF INDIAN STANDARDS RELATING TO FIRE SAFETY / FIRE PROTECTION (As given in NBC Part-4) IITK-GSDMA-Fire 05-V3.0 Page 249 .
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Handbook on Building Fire Codes Annex .D CALORIFIC VALUES OF COMMON MATERIALS AND TYPICAL VALUES OF FIRE LOAD DENSITY (As given in NBC Part-4) below: IITK-GSDMA-Fire 05-V3.0 Page 258 .
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IITK-GSDMA-Fire 05-V3.Handbook on Building Fire Codes A-2 The typical values for Fire Load Density for arriving at the Classification of Occupancy Hazard is given below for guidance.0 Page 260 .
Handbook on Building Fire Codes Annex .E (As given in NBC Part-4) IITK-GSDMA-Fire 05-V3.0 Page 261 .
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Handbook on Building Fire Codes Annex .0 Page 265 .F QUALIFICATIONS AND EXPERIENCE PROPOSED FOR FIRE PROTECTION ENGINEER / CONSULTANT FOR REGISTRATION / ACCREDITATION (Proposed by the Authors for inclusion in the documents revised as per GSDMA Project) IITK-GSDMA-Fire 05-V3.
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f In times to come. when all foreign and private players were asked to wind up their shops and merge into 4 government companies.0 Page 268 . Then came the nationalization of Insurance Industry in 1970. Then came the privatisation of Indian insurance industry in the year 1999. Current Fire Tariff which has come into effect from 31. Present fire tariff which has come into effect with effect from 31. main provisions of the new tariff and those of the old tariff are reproduced below for ready reference. More than a century ago Fire insurers in India.day. There were four tariffs operating in the country for its four geographical regions viz east west north and south. when 8 private insurance companies were allowed to do business side by side. with the four giant nationalized companies. which prohibits insurers from deviating from rates terms and conditions indicated therein. Keeping in view of the above. Tariffs are still being retained but in a much simpler form. it was decided to do away with 4 regional tariffs and follow only one All India Fire Tariff. to distinguish between a good risk from a bad one.) IITK-GSDMA-Fire 05-V3.3. readers would find it convenient to refer the old tariff.2001. It is only a miniature version of what it was all along during its existence for more that! a hundred years in the past.Handbook on Building Fire Codes Annex . from all over the globe. decided to form an Insurance Association of India to safeguard their common interests.2001 provides for the following: Entire insured property in the same industrial compound carry the same rate. some 106 in nos. Meanwhile in the year 1987. competing with each other. when tariffs are removed to facilitate open competition.AN UPDATE Insurance industry in India has taken a full turn.3. prevalent in most global markets to. from days of open competition.G ROLE OF INSURANCE INDUSTRY VIS-A-VIS RISK MANAGEMENT MEASURES . is perhaps in its simplest form. Fire insurance policy in India is governed by by Indian Fire Tariff.(In the earlier tariff each individual block was rated on its own meritsDifferential rates were considered for blocks segregated by perfect party walls and double fire proof doors. then to purely a nationalized industry and now to an environment trying to catch up with truly competitive era.
5%+5% Hand appliances. such manufacturing blocks are however still rated 'per se" in the new tariff if they are located detached. RCC framed structures. These vary from 2%. Now compare this with the provisions of earlier All India fire tariff given below. The difference in rates between a class I building and a class II building used to be varying from Rs 0. for upto 5% claims experience and the maximum loading charged is 100%. Buildings having walls of other than brick work were considered as class II buildings and were charged rates higher than those applicable to class I buildings which were necessarily required to have brick walls all around. Discounts granted for fire protection systems are as follows: Hand Appliances and hydrant System-5% Hand appliances and independent sprinkler/fixed water spray system-7.0 Page 269 . IITK-GSDMA-Fire 05-V3. with brick/ RCC walls all. RCC floors and RCC staircases. for opting deductible of 5% OF CLAIM AMOUNT SUBJECT TO MINIMUM OF Rs 10 lacs for ACT Of GOD perils (and Rs 5 Lacs for other perils). Providing different rates for different constructions has been done away with However. Buildings of superior constructions were granted a discount of 10% . to 25% for opting deductible of 5% OF CLAIM AMOUNT SUBJECT TO MINIMUM OF Rs 20 crores for ACT Of GOD perils (and Rs 10 crores for other perils). additional rate of Rs 4.25%0 to 1.80%0. Maximum discount granted is 15%.00%0 for buildings (and their contents)having walls and /or roofs of wooden planks/thatched leaves and/ or grass/hayof any kind/bamboo/plastic cloth/asphalt cloth/canvas/tarpaulin and the like which are treated as of kutcha construction for rating.Handbook on Building Fire Codes If two or more independent products are manufactured in the same compound.around. RCC roofs. Insurers are also allowed to grant discounts for voluntary deductibles opted by insureds. were considered as of superior construction. Hydrant system and independent sprinkler/fixed water spray system-10%+5% Risks having sum insured (in one compound of one complex in one location) of Rs 50 crores and above attract claim experience discounts/ loadings based on claims experience of preceeding three years (excluding the expiring policy period). for risks producing claims experience above 500%.
which mainly included following. A discount of 10% on tariff rates was permitted. Loading per floor was 0. paper mills. which had to be below 10% (for claims experience of below 5% for last 10 years this could be increased to 15% On top of this a maximum discount of up-to 25% could be allowed for good physical features. jute mills and textile mills.5% Hand appliances and independent sprinkler/fixed water spray system-35% Hand appliances.5% Hand appliances and trailer pumps/ fire engine-7. if electrical installations complied with the requirements of IS: 1646.0 Page 270 . Hydrant system and fixed Co2/DCP/FOAM HALON/HALON alternatives systems -45% Automatic fire alarm systems.2. woolen mills.Handbook on Building Fire Codes Buildings with wooden floors were charged a loading of Rs 0. neither there were loadings for bad claims experience.25%0 in case of tea factories. Discounts granted for fire protection systems were as follows: Hand appliances. Discount of up-to 10% was available on risks having sum insured above Rs 25 crores for good claims experience for the past 5 years (excluding the expiring policy period). Hydrant system and independent sprinkler fixed water spray system-50%/45% Hand appliances. • Proximity of public fire brigades • Compound wall/fencing all around with gates wide enough for entry of fire brigade vehicles • Provision of fire hydrant system • Additional water supplies and pumping capacities than what are normally required under rules • Provision of fire engines • Full time works brigade for fire fighting • Fulltime fire/safety officer • Safety committees • Workers training in plant operation /safety • Hot/cold work.40%0 for each upper floor in respect of flour mills.5% Mutual Aid schemes-5% Co2 flooding system in textile blow rooms-20% Diversion system in textile blow rooms-10% There was no scheme for voluntary deductible.permit systems • No smoking signs IITK-GSDMA-Fire 05-V3.5% Hand Appliances and hydrant System-22.
Handbook on Building Fire Codes • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Good housekeeping Provision of an incinerator.0 Page 271 . Explosion suppression systems Continuous electrical bonding and grounding of chemical process equipments Adequate relief systems on pressure vessels Proven processes Suitable drainage system for safe handling of liquid effluents Provision of refuge areas in high rise buildings Segregation of lift wells and staircases in high rise buildings with provision of a one hour fire resistance fire door at every landing Incombustible baffles at every alternate floor in service shafts/cable ducts with one hour fire resistance shutters at every floor A permanent vent at top of every shaft Staggering windows with projecting ledges in external walls Drencher sprinklers every three floors Segregation of fuel storages. at a safe location for burning of wastes. IITK-GSDMA-Fire 05-V3. Adequate aisle space and clearances from walls and ceilings in Godowns Compliance with Explosive Regulations Fire proofing of steel supports of spheres Segregation/separation of plant control rooms. fire pump rooms and transformer rooms Independent air conditioning systems for every floor. Physical separation between blocks for exposure protection Blocks located at safe distance from boundary walls Fireproofing of structural steelwork supports of building RCC roofs Vertical Separations Non combustible false ceilings/wall linings/ductings Explosion venting Compartmentation Provision of fire dampers Doors/windows in external walls to facilitate fire fighting Absence of Continuous working Segregation of boiler rooms/Thermic fluid heaters Electrical interlocks for thermic fluid heaters/ovens/vessels/driers Use of LPG gas/ Liquid fuel Elevated floor surfaces for Godowns Storage on pallets/racks in warehouses Only manual or battery type goods handling vehicles.
(old concept) Fig-9 Uninhibited / Unbroken Chain Reaction showing active radicals like H*.Handbook on Building Fire Codes Annex . and Cooling(C) Fig-12 Tetrahedron of Fire Fig-13 Fire Extinguishment(Fourth Factor) Fig-14 Fusible Link Detector Fig-15 Heat detector using expansion of metal strip principle Fig-16 Heat detector .Obscuration Type-Non-fire condition 41 44 45 66 67 68 68 69 70 70 71 72 72 IITK-GSDMA-Fire 05-V3.H LIST OF FIGURES FIGURES Fig-1 PAGE 23 24 25 26 27 29 29 38 39 41 Showing methods of Heat Transmission (i) Conduction (ii) Convection (iii) Radiation Fig-2 Fire spread in a building due to Conduction of heat along an unprotected steel beam/girder Fig-3 Showing how fire on a lower floor can spread to upper floors by convection Fig-4 Showing the inverse square law in radiation Fig-5 Clothing can get ignited if placed too close to a source of radiation Fig-6 A diffusion flame Fig-7 A premixed flame Fig-8 Triangle of Fire showing the three constituents of fire.Bi-metal strip type Fig-17 Heat detector . O* & OH* in the flame Fig-10 Fire Extinction Methods Fig-11 Triangle of Fire showing the three conventional methods of fire extinguishment-Starvation(A).Using principle of expansion of air (pneumatic detector) Fig-19 (a) Ionisation Detector .Rate-of-rise principle Fig-18 Heat detector .Non-fire condition Fig-19 (b) Ionisation Detector -fire condition Fig-20 (a) Optical Detector .0 Page 272 . Smothering(B).Light scatter type(fire condition) Fig-21 (a) Optical Detector .Light scatter type(Non fire condition) Fig-20 (b) Optical Detector .
0 Page 273 .Obscuration Type-fire condition Fig-22 Forms of radiant energy produced in a fire Fig-23 Components of an Infra-red Detector Fig-24 A typical Infra-red Detector Fig-25 A typical Infra-scan Detector Fig-26 Components of an Ultra-violet Detector Fig-27 Stand-post type Hydrant Fig-28 Underground Hydrant-Sluice valve type Fig-29 Typical Hydrant Box Fig-30 Layout of a Typical Sprinkler Installation Fig-31 A typical fusible solder type sprinkler head showing component parts Fig-32 A typical fusible bulb type sprinkler head showing component parts Fig-33 Types of sprinklers (bulb type) (1) Ceiling flush pattern (2) Sidewall pattern (3) Pendent type (4) Dry upright type Fig-34 Diagramatic lay out of pipework of a sprinkler installation.Handbook on Building Fire Codes Fig-21 (b) Optical Detector . Fig-35 Two types of High Velocity Water Spray projectors Fig-36 Automatic Water Spray projector system Fig-37 High Velocity Water Spray System for Transformer Protection Fig-38 A typical deluge system Fig-39 A typical drencher system Fig-40 A typical Inline Inductor Fig-41 Inline Variable Inductor with control knob for regulating foam concentrate induction rate Fig-42 Diagrammatic lay out of Round-the-Pump Proportioner Fig-43 Foam chamber and pourer with vapour shield Fig-44 Foam system installed on the floating roof top Fig-45 Layout of semi subsurface foam system Fig-46 A typical medium expansion foam generator Fig-47 Principles of operation of a high expansion foam generator 72 73 74 74 75 76 93 94 94 99 101 102 104 105 110 111 111 113 114 116 117 117 124 127 129 131 132 IITK-GSDMA-Fire 05-V3.
30 NFPA Fire Protection Handbook: Figure 51 BS: Figures 48. 49. 5. 58. HMSO Manual of Firemanship Book 7: Figure 29 HMSO Manual of Firemanship Book 9: Figures 14. 50. 61-A. 46. 60. 16. 53. 41. 47. 17. 55. 21(b). 42. 62. IITK-GSDMA-Fire 05-V3. 24. 20(b). 61-B. 2.Handbook on Building Fire Codes Fig-48 Fig-49 Fig-50 Fig-51 Fig-52 Fig-53 Fig-54 Typical High Expansion Foam System for Warehouse-133 Low pressure CO2 Storage Unit 135 CO2 Total Flooding System protecting turbo generator 135 A CO2 Extinguishing System that has been activated 136 CO2 Local Application System protecting quench tank136 Standard warning symbol of a CO2 Installation 141 Dry Chemical Extinguising System (for protection of cooking range) 144 Fig-55 Halon Total Flooding System for oil-filled switchgear & transformers 150 Fig-56 Halon Modular Total Flooding System protecting electronic data processing equipment and tape storage rooms 151 Fig-57 Water(Gas Cartridge) type extinguisher 165 Fig-58 Water(Stored Pressure) type extinguisher 166 Fig-59-A Mechanical Foam Extinguisher (Store Pressure Type) 167 Fig-59-B Mechanical Foam Extinguisher (Gas CartridgeType) 167 Fig-59-C Method of Operation of Foam Extinguisher 168 Fig-60-A Dry Powder Extinguisher(Stored Pressue) type 169 Fig-60-B Dry Powder Extinguisher(Gas Cartridge) . 56.0 Page 274 . 3. 59(a). 19(b). 26. 22. 30.two types 170 Fig-61 CO2 Extinguisher 171 Acknowledgement: The figures mentioned above have been adopted courtesy foreign Manuals / Books as indicated below: HMSO Manual of Firemanship Book 1: Figures 1. 59-B. 8. 20(a). 21(a). to 39. 4. 52. IFE Fire Technology: Figures 29. 18. 54. 57. 25. 15. 11. 19(a). HMSO Manual of Firemanship Book 3: Figures 40. 23.
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