Tear gas is any of several chemicals that cause the eyes to fill with tears . Tear gas can also cause a burning sensation when it touches skin. If inhaled, it can cause intense sneezing , coughing , or choking. The effects of tear gas usually appear within one minute of exposure. The effects can be severe, but they are usually temporary.
Police in many countries use tear gas to help control rioting crowds. They shoot canisters of tear gas into the crowd. The canisters release the tear gas in a thick cloud. Private citizens sometimes carry tear gas in small aerosol containers for self-protection. Such products are often called Mace. The term Mace is a trademark of Mace Security International.
The active chemical in tear gas is not actually a gas. It is usually a solid or liquid. Particles of the chemical are mixed into a gas or another liquid, which can then be sprayed or otherwise directed at targets. Some of the most common types of tear gas are called CN (short for chloroacetophenone) and CS (chlorobenzylidene malononitrile) gas.
Tear gas is considered a nonlethal irritant. But some types of tear gas have been reported to cause serious injury and death, especially in people with asthma . CS gas has largely replaced CN gas because CS gas is both more effective and less toxic to humans.
Tear gas is sometimes combined with other compounds to give it additional properties. CN or CS gas can be mixed with a compound called OC gas. OC gas—short for oleoresin capsicum—is made from a chemical found in chili peppers and generally works faster than tear gas. It is also more effective in controlling violent aggressors. Tear gas can also be laced with dye , marking targets for later identification.
