§ 185.352 § 185.352 Ventilation of gasoline machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space, required by § 182.460(a)(1)(ii) of this chapter, must be operated prior to starting gasoline engines for the time sufficient to insure at least one complete change of air in the space served.
46 CFR §185.352
46 CFR Part 185
TL;DR
§ 185.352 § 185.352 Ventilation of gasoline machinery spaces.