This Week in Toxicology

By James Chenoweth MD MAS Disclaimer: Any opinions expressed in this article are my own. Recent protests over the murder of George Floyd by police in Minneapolis, Minnesota have often been met with police use of “non-lethal” (better described less lethal) forms of crowd control/dispersal. The most common of these include tear gas, pepper spray, and impact rounds (beanbag rounds and rubber bullets). Emergency physicians and toxicologists should know what compounds these devices contain and the risks associated with their use by police. Tear Gas Tear gas is a heterogenous group of compounds that are irritant gases which cause coughing, eye irritation, and skin irritation upon exposure. The most common of these compounds in current us is CS (chlorobenzylidene malononitrile) gas. CS was developed in 1928 and is named after its creators, Corson and Stoughton. It was first used by the British Army in 1958 and was frequently used by the US military during the Vietnam War. 1 The mi