What are sulfur mustard agents H/HD and HT?
Sulfur mustards H/HD and HT are manufactured compounds. They are colorless when pure, but are typically yellow to brown oily liquids with a slight garlic or mustard odor. Agent H contains about 20-30% impurities. The nearly pure substance is called HD. HT is a mixture of 60% HD and 40% of another substance called agent T. They do not dissolve much in water, but dissolve easily in oils, fats, and other solvents. They are stable at ambient temperatures. Sulfur mustards were introduced as chemical warfare agents during World War I. More than a dozen countries have sulfur mustard agents in their chemical arsenals. Destruction of U.S. stockpiles of chemical agents, including sulfur mustards, was mandated by the Chemical Weapons Convention to take place before April 2007.