Mustard gas or sulfur mustard are names commonly used for the organosulfur chemical compound bis(2-chloroethyl) sulfide, which has the chemical structure S(CH2CH2Cl)2, as well as other species. In the wider sense, compounds with the substituents −SCH2CH2X or −N(CH2CH2X)2 are known as sulfur mustards or nitrogen mustards, respectively, where X = Cl or Br. Such compounds are potent alkylating agents, making mustard gas acutely and severely toxic.[3] Mustard gas is a carcinogen.[3] There is no preventative agent against mustard gas, with protection depending entirely on skin and airways protection, and no antidote exists for mustard poisoning.[4]
Also known as mustard agents, this family of compounds comprises infamous cytotoxins and blister agents with a long history of use as chemical weapons.[4] The name mustard gas is technically incorrect; the substances, when dispersed, are often not gases but a fine mist of liquid droplets that can be readily absorbed through the skin and by inhalation.[3] The skin can be affected by contact with either the liquid or vapor. The rate of penetration into skin is proportional to dose, temperature and humidity.[3]
Sulfur mustards are viscous liquids at room temperature and have an odor resembling mustard plants, garlic, or horseradish, hence the name.[3][4] When pure, they are colorless, but when used in impure forms, such as in warfare, they are usually yellow-brown. Mustard gases form blisters on exposed skin and in the lungs, often resulting in prolonged illness ending in death.[4]
