This helps in assuring accountability within the team. They must operate together as a team all the time they are in the hazard area. If one firefighter has to leave the hazard area, for any reason, such as air supply getting low, they must both exit. Two-out OSHA requires that one of the two firefighters outside must be dedicated to accounting for the two firefighters inside, and, if necessary, initiate a fire fighter rescue. The other firefighter is permitted to take on other roles, such as incident commander in charge of the emergency incident, safety officer or equipment/pump operator. However, the second firefighter outside cannot be assigned tasks that are critical to the safety and health of any other employee working at the incident. These rules also apply to all training with live fires inside structures, and are even more important when inexperienced trainees are inside. (OSHA) only when firefighters are engaged in the interior attack of an interior structural fire that the "two-in/two-out" requirement applies. It does not prohibit firefighters from entering a structure fire to do a search before an entire team has been assembled The standard does not require the "two-in/two-out" provision if the fire is still in the incipient stage and it does not prohibit firefighters from fighting the fire from outside before sufficient personnel have arrived. It also does not prohibit firefighters from entering a burning structure to perform rescue operations when there is a reasonable belief that victims may be inside. It is only when firefighters are engaged in the interior attack of an interior structural firefighting that the "two-in/two-out" requirement applies. The interpretation covers the number of persons who must be on the scene before fire fighting personnel may begin the interior attack on an interior structural fire. Until those persons arrive on the scene, fire fighters may fight the blaze from outside the structure and carry out rescue activities. Incipient stage fire An incipient stage fire is defined as a fire that is in the initial or beginning stage and can be controlled or extinguished by portable fire extinguishers, Class II standpipe, or small hose systems without the need for protective clothing or breathing apparatus. Note 2 to paragraph (g): Nothing in this section is meant to preclude firefighters from performing emergency rescue activities (Search) before an entire team has assembled. Rapid intervention crew The National Fire Protection Association (NFPA) defines the