14 CFR §25.869

1. (a)Electrical system components:
   1. (1)Components of the electrical system must meet the applicable fire and smoke protection requirements of §§ 25.831(c) and 25.863.
   2. (2)Equipment that is located in designated fire zones and is used during emergency procedures must be at least fire resistant.
   3. (3)EWIS components must meet the requirements of § 25.1713.
2. (b)Each vacuum air system line and fitting on the discharge side of the pump that might contain flammable vapors or fluids must meet the requirements of § 25.1183 if the line or fitting is in a designated fire zone. Other vacuum air systems components in designated fire zones must be at least fire resistant.
3. (c)Oxygen equipment and lines must—
   1. (1)Not be located in any designated fire zone,
   2. (2)Be protected from heat that may be generated in, or escape from, any designated fire zone, and
   3. (3)Be installed so that escaping oxygen cannot cause ignition of grease, fluid, or vapor accumulations that are present in normal operation or as a result of failure or malfunction of any system.