CS gas is a non-lethal chemical agent used primarily as a crowd control and riot-suppression tool. It causes severe and debilitating reactions in the tear ducts and mucus membranes. This agent was first used in the late 1950s and is widely used to combat civil unrest. Modern gas masks offer excellent protection against CS gas.
This chemical compound was first isolated in 1928 and is named for the men, Corson and Stoughton, who first developed its active ingredient. This ingredient, 2-chlorobenzalmalononitrile is mixed with other chemicals to turn it into a gas. Most commonly this chemical agent is deployed using small grenade-like canisters, which may be thrown or launched. Spray delivery systems are also sometimes used.
The most common name for this compound is “tear gas”. This name derives from the most prominent physical effects of the gas. Other chemical agents with similar debilitating but non-lethal effects may also be referred to as “tear gas," however.
Reactions to CS gas vary to some extent, but are typically both painful and debilitating. The substance irritates the eyes and mucous membranes, which makes vision difficult. Breathing after exposure to CS gas is also difficult and can be quite painful. Many people exposed to this substance find it impossible to breathe through their nostrils. Other physical effects, including pain and nausea, are also not uncommon.
International treaties prohibit the use of CS gas during warfare, as it is considered a chemical weapon. These treaties do not ban its use by police against civilians, however. It is widely used as a riot control agent and crowd dispersal tool. Police are often reluctant to use it in confined spaces, as the effects of CS gas can induce dangerous panic when no easy path of escape from the chemical agent is available.
Opinion remains divided over the dangers posed by exposure to this gas. It is generally accepted that the gas is non-lethal, but may pose additional risks for people with specific health conditions. Asthmatics, for instance, may experience more severe difficulties.
Modern gas masks are highly effective in protecting a wearer against the effects of this gas. The compound may still cause irritation of the skin, however. This occurs because the chemical irritant can penetrate into pores, and this causes a painful reaction. Heavy clothing can limit this effect, as can taking care not to rub areas that are exposed to CS gas. Warm weather exacerbates the topical effect of the gas, because sweating causes pores to open wider.