CS gas is a powerful irritant that is used in riot control and other situations where crowds need to be dispersed. The chemical is sometimes called tear gas, and it causes burning sensations in the eyes, nose, and throat, as well as difficulty breathing. Other synonyms for CS gas include o-chlorobenzylidenemalononitrile, chlorobenzylidene malononitrile, and CS. CS gas is non-lethal, but it can still be dangerous, particularly for vulnerable groups such as children, the elderly, and those with respiratory conditions. When used responsibly, however, CS gas is an effective tool for law enforcement and public safety personnel to maintain order and protect the public.