CS gas
chemical compound
The compound 2-chlorobenzalmalononitrile (also called o-chlorobenzylidene malononitrile; chemical formula: C10H5ClN2), a cyanocarbon, is the defining component of the lachrymatory agent commonly called CS gas, a tear gas used as a riot control agent, and is banned for use in warfare pursuant to the 1925 Geneva Protocol.
Exposure causes a burning sensation and tearing of the eyes to the extent that the subject cannot keep their eyes open, and a burning irritation of the mucous membranes of the nose, mouth and throat, resulting in profuse coughing, nasal mucus discharge, disorientation, and difficulty breathing, partially incapacitating the subject. CS gas is an aerosol of a volatile solvent (a substance that dissolves other active substances and that easily evaporates) and 2-chlorobenzalmalononitrile, which is a solid compound at room temperature. CS gas is generally accepted as being a non-lethal weapon.
History
CS gas was first synthesized by two Americans, Ben Corson and Roger Stoughton, at Middlebury College in Vermont in 1928, and the chemical's name is derived from the first letters of the scientists' surnames.
CS was developed and tested secretly at Porton Down in Wiltshire, UK, in the 1950s and 1960s. CS was used first on animals, and subsequently on British Army servicemen volunteers. CS has less effect on animals because they have different tear ducts and, in the case of non-human mammals, their fur inhibits the free entry of the gas.
As recently as 2002, the U.S. State Department Bureau of International Security and Nonproliferation made a firm distinction between "riot-control agents" such as CS gas, and "lethal chemical weapons." The Bureau cited support for this position from the U.K. and Japan.
The use of CS in warfare has been prohibited under the Chemical Weapons Convention.
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This entry incorporates text from “CS gas” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.