When a vessel is carrying sulfur dioxide, the master shall ensure that:

(a) A cargo tank is dry before it is loaded with sulfur dioxide; and

(b) Air or inert gas admitted into a cargo tank carrying sulfur dioxide during discharging or tank breathing has a moisture content equal to or less than the moisture content of air with a dew point of −45 °C (−49 °F) at atmospheric pressure.

[CGD 74-289, 44 FR 26009, May 3, 1979, as amended by USCG-2014-0688, 79 FR 58285, Sept. 29, 2014]