What is the requirement for fire fighting equipment on board a passenger flight?
You have this tagged  both FAA and ICAO but for the FAA thats governed under 


  § 121.309 Emergency equipment.
  
  (c)Hand fire extinguishers for crew, passenger, cargo, and galley
  compartments. Hand fire extinguishers of an approved type must be
  provided for use in crew, passenger, cargo, and galley compartments in
  accordance with the following:
  
  (1) The type and quantity of extinguishing agent must be suitable for
  the kinds of fires likely to occur in the compartment where the
  extinguisher is intended to be used and, for passenger compartments,
  must be designed to minimize the hazard of toxic gas concentrations.
  
  (2)Cargo compartments. At least one hand fire extinguisher must be
  conveniently located for use in each class E cargo compartment that is
  accessible to crewmembers during flight.
  
  (3)Galley compartments. At least one hand fire extinguisher must be
  conveniently located for use in each galley located in a compartment
  other than a passenger, cargo, or crew compartment.
  
  (4)Flightcrew compartment. At least one hand fire extinguisher must be
  conveniently located on the flight deck for use by the flightcrew.
  
  (5)Passenger compartments. Hand fire extinguishers for use in
  passenger compartments must be conveniently located and, when two or
  more are required, uniformly distributed throughout each compartment.
  Hand fire extinguishers shall be provided in passenger compartments as
  follows:
  
  (i) For airplanes having passenger se ats accommodating more than 6
  but fewer than 31 passengers, at least one.
  
  (ii) For airplanes having passenger se ats accommodating more than 30
  but fewer than 61 passengers, at least two.
  
  (iii) For airplanes having passenger se ats accommodating more than 60
  passengers, there must be at least the following number of hand fire
  extinguishers:
  
  Minimum Number of Hand Fire Extinguishers Passenger seating
  accommodations:  
  
  61 through 200:   3 
  
  201 through 300:  4 
  
  301 through 400:  5
  
  401 through 500:  6 
  
  501 through 600:  7 
  
  601 or more:  8 
  
  (6) Notwithstanding
  the requirement for uniform distribution of hand fire extinguishers as
  prescribed in paragraph (c)(5) of this section, for those cases where
  a galley is located in a passenger compartment, at least one hand fire
  extinguisher must be conveniently located and easily accessible for
  use in the galley.
  
  (7) At least two of the required hand fire extinguisher installed in
  passenger-carrying airplanes must contain Halon 1211
  (bromochlorofluoromethane) or equivalent as the extinguishing agent.
  At least one hand fire extinguisher in the passenger compartment must
  contain Halon 1211 or equivalent.


You may also find some pertinent info here.