Trichloromethyl sulfur chloride Perchloromethyl mercaptan is the organosulfur compound with the formula CCl3SCl.

Shortly thereafter, wartime use was abandoned due to the clear warning properties, the decomposition in the presence of iron and steel, and the easy removal of the vapor by charcoal.

The more volatile byproducts such as carbon tetrachloride and sulfur dichloride can be removed by distillation.

The separation of perchloromethyl mercaptan from S2Cl2 by distillation is challenging since their boiling points are very close.

Perchloromethyl mercaptan is oxidized by nitric acid to trichloromethanesulfonyl chloride (Cl3CSO2Cl), a white solid.