Hydrogen Sulfide Exposure from Molten Sulfur-A Forgotten Hazard?

摘要

Molten sulfur is one of the most frequently transported hazardous materials (hazmat) in NorthAmerica. Molten sulfur is typically transported at an elevated temperature by rail tank cars orover-the-road tank trailers as a Class 9 "Miscellaneous Hazardous Material" under theidentification number NA2448. Perhaps the most prominent hazard of molten sulfur is that it isshipped at an elevated temperature, which can cause thermal burn injuries. A less obvioushazard is the potential release of hydrogen sulfide (H_2S), a highly toxic gas.In this paper we first summarize the key features of the H_2S-molten sulfur equilibrium that arerelevant to this hazard. Then we address the relative risk of H_2S exposure from an analysis ofmolten sulfur incident release statistics. Next, we discuss a few case studies in which vented H_2Sgas from molten sulfur led to unexpected consequences for handling personnel. We close ourdiscussion with suggestions for how to possibly prevent H_2S exposure through a combination ofengineering controls, operating procedures for both loading and unloading operations, airmonitoring, and personal protection equipment.