46 CFR §127.225

1. (a)Each OSV of at least 6,000 GT ITC (500 GRT if GT ITC is not assigned) must comply with the provisions of Chapter II-2 of SOLAS, 1974, as amended (incorporated by reference, see § 125.180), for Method IC cargo ships.
2. (b)All structural fire-protection materials must be approved by the Coast Guard in accordance with the regulations of subpart 2.75 of this chapter.
3. (c)The exterior boundaries of superstructures, except wheelhouses, containing accommodation, service and control spaces, facing the cargo area must be constructed of steel and comply with §§ 32.56-20, 32.56-21, and 32.56-22 of this chapter.
4. (d)Cargo pump rooms must be separated from accommodation spaces, service spaces, and control stations by A-60 divisions.
5. (e)Cargo pump rooms must be separated from machinery spaces of category A by A-0 divisions.