14 CFR § 25.851

Hand fire extinguishers. (1) The following minimum number of hand fire extinguishers must be conveniently located and evenly distributed in passenger compartments:

At least one hand fire extinguisher must be conveniently located in the pilot compartment.

At least one readily accessible hand fire extinguisher must be available for use in each Class A or Class B cargo or baggage compartment and in each Class E or Class F cargo or baggage compartment that is accessible to crewmembers in flight.

At least one hand fire extinguisher must be located in, or readily accessible for use in, each galley located above or below the passenger compartment.

Each hand fire extinguisher must be approved.

At least one of the required fire extinguishers located in the passenger compartment of an airplane with a passenger capacity of at least 31 and not more than 60, and at least two of the fire extinguishers located in the passenger compartment of an airplane with a passenger capacity of 61 or more must contain Halon 1211 (bromochlorodifluoromethane CBrC1 F2), or equivalent, as the extinguishing agent. The type of extinguishing agent used in any other extinguisher required by this section must be appropriate for the kinds of fires likely to occur where used.

The quantity of extinguishing agent used in each extinguisher required by this section must be appropriate for the kinds of fires likely to occur where used.

Each extinguisher intended for use in a personnel compartment must be designed to minimize the hazard of toxic gas concentration.

Built-in fire extinguishers. If a built-in fire extinguisher is provided—

Each built-in fire extinguishing system must be installed so that—

No extinguishing agent likely to enter personnel compartments will be hazardous to the occupants; and

No discharge of the extinguisher can cause structural damage.

The capacity of each required built-in fire extinguishing system must be adequate for any fire likely to occur in the compartment where used, considering the volume of the compartment and the ventilation rate. The capacity of each system is adequate if there is sufficient quantity of agent to extinguish the fire or suppress the fire anywhere baggage or cargo is placed within the cargo compartment for the duration required to land and evacuate the airplane.