Each fire wall and shroud must --
(a) Be so made that no hazardous quantity of air, fluids, or flame can pass from the engine compartment to other parts of the airplane;
(b) Have all openings in the fire wall or shroud sealed with close-fitting fire-proof grommets, bushings, or firewall fittings;
(c) Be made of fireproof material; and
(d) Be protected against corrosion.