Gas

In its history, various types and mixtures of mustard gas have been employed. These include: H – Also known as HS ("Hun Stuff") or Levinstein mustard. This is named after the inventor of the "quick but dirty" Levinstein Process for manufacture,[21][22] reacting dry ethylene with disulfur dichloride under controlled conditions. Undistilled mustard gas contains 20–30% impurities, which means it does not store as well as HD. Also, as it decomposes, it increases in vapor pressure, making the munition it is contained in likely to split, especially along a seam, releasing the agent to the atmosphere.[1] HD – Codenamed Pyro by the British, and Distilled Mustard by the US.[1] Distilled mustard of 95% or higher purity. The term "mustard gas" usually refers to this variety of mustard. HT – Codenamed Runcol by the British, and Mustard T- mixture by the US.[1] A mixture of 60% HD mustard and 40% O-Mustard, a related vesicant with lower freezing point, lower volatility and similar vesicant characteristics. HL – A blend of distilled mustard (HD) and lewisite (L), originally intended for use in winter conditions due to its lower freezing point compared to the pure substances. The lewisite component of HL was used as a form of antifreeze.[23] HQ of antifreeze.[23] HQ [End}