46 C.F.R. § 154.1405 Respiratory protection.
Title 46 - Shipping
When Table 4 references this section, a vessel carrying the listed cargo must have: (a) Respiratory protection equipment for each person on board that protects the person from the cargo vapor for at least 5 minutes; and (b) Two additional sets of respiratory protection equipment that: (1) Are stowed in the wheelhouse; and (2) Protects the wearer from the cargo vapor for at least 5 minutes.
Title 46: Shipping
PART 154—SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES
Subpart C—Design, Construction and Equipment
Safety Equipment
§ 154.1405 Respiratory protection.

