Section 125.145 - Firewall constructionEach firewall 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 firewall or shroud sealed with close-fitting fireproof grommets, bushings, or firewall fittings;(c) Be made of fireproof material; and(d) Be protected against corrosion.