Section 153.545 - Special requirements for liquid sulfur(a) A containment system carrying liquid sulfur must have: (1) A cargo tank ventilation system that: (i) Maintains the H2 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.