StacksVerified U.S. regulatory reference

46 CFR §30.10-6a

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
The term Category A machinery space means any space and trunks and ducts to such a space that contains:
  1. (a)Internal combustion machinery used for main propulsion;
  2. (b)Internal combustion machinery used for purposes other than main propulsion where the total aggregate power is at least 500 brake horsepower;
  3. (c)Internal combustion machinery that uses a fuel that has a flash point of less than 43.3°C (110°F); or
  4. (d)One or more oil fired boilers or oil fuel units.