Special requirements for liquid sulfur.

(a) A containment system carrying liquid sulfur must have: (1) A cargo tank ventilation system that: (i) Maintains the H 2 S vapor concentration below 1.85 percent by volume; and (ii) Prevents sulfur buildup within itself; and (2) An alarm system designed to operate when the ventilation system blower fails. (b) The void spaces around a cargo tank that carries liquid sulfur must be oil tight. (c) A cargo tank that carries liquid sulfur and the void spaces surrounding the tank must have connections for sampling vapor.