According to 46 CFR Subchapter T, how long should exhaust blowers be operated in enclosed spaces containing gasoline powered machinery before starting the engine?

Correct Answer: Option C — Long enough to achieve at least one complete change of air

46 CFR 182.460(j) mandates that exhaust blowers in spaces containing gasoline machinery must be operated for a duration sufficient to achieve at least one complete change of air before starting the engine. This procedure ensures that any accumulated fuel vapors are cleared, significantly reducing the risk of ignition.