46 C.F.R. § 153.934 Entry into spaces containing cargo vapor.
Title 46 - Shipping
(a) No person may enter a cargo tank, cargo handling space, pumproom or enclosed space in the cargo area without the permission of the master. (b) Before permitting anyone to enter a cargo tank, cargo handling space, pumproom or other enclosed space in the cargo area, the master shall make sure that: (1) The space is free of toxic vapors and has sufficient oxygen to support life; or (2) Those entering the space wear protective equipment with self-contained breathing apparatus as described in §153.214(b) and an officer closely supervises the entire operation. [CGD 73–96, 42 FR 49027, Sept. 26, 1977, as amended by CGD 78–128, 47 FR 21210, May 17, 1982]
Title 46: Shipping
PART 153—SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS
Subpart C—Operations
General Vessel Safety
§ 153.934 Entry into spaces containing cargo vapor.