Tear gas
non-lethal chemical weapon / From Wikipedia, the free encyclopedia
Tear gas is the name for a number of chemical compounds. They are not actually gases.[1] They are fine powders or mists of liquid. The chemicals are acidic and cause pain in the eyes. Tear gas may cause temporary blindness for up to 45 minutes. Tear gas is commonly used by police to control crowds. Phenacyl chloride (CN) liquid and CS powder are two of the chemicals that are often found in tear gas. Pepper spray is another chemical compound that acts very similarly and is sometimes used to control crowds.
Tear gas is a chemical weapon, and was used as a weapon in the First World War. The 1925 Geneva Protocol is not specific enough about the use of irritating agents, such as tear gas in war. The Chemical Weapons Convention, of 1992 prohibits the use of tear gas for warfare. The use as a riot control agent is not covered by the treaty.