46 CFR § 153.240
Insulation
April 15, 2021
Cargo containment system insulation made necessary by the requirements of this part must meet the requirements in §38.05-20 of this chapter. However, the vapor barrier required by §38.05-20(b) is unnecessary if the insulation is:
(a) Protected from the weather, and attached to a containment system maintained at a temperature in excess of 46 °C (approx. 115 °F); or
(b) In an atmosphere whose dew point is less than the temperature of any surface in contact with the insulation.
[CGD 73-96, 42 FR 49027, Sept. 26, 1977, as amended by USCG-2014-0688, 79 FR 58284, Sept. 29, 2014]