tear gas

tear gas, gas that causes temporary blindness through the excessive flow of tears resulting from irritation of the eyes. The gas is used in chemical warfare and as a means for dispersing mobs. Compounds that cause lacrimation (watering of the eyes) include bromoacetone, benzyl bromide, chloroacetophenone, ethyl iodoacetate, chloropicrin bromobenzyl cyanide, and bromine-substituted xylenes. In warfare a lacrimating compound in liquid form is placed in bombs, shells, or grenades; when the device explodes, the liquid is dispersed as an aerosol.

Any of a group of substances, most often synthetic organic halogen compounds, that irritate the mucous membranes of the eyes, causing a stinging sensation and tears. They may also irritate the upper respiratory tract, causing coughing, choking, and general debility. Tear gas was first used in warfare in World War I, but since its effects are short-lasting and rarely disabling, it came into use by law-enforcement agencies as a means of dispersing mobs, disabling rioters, and flushing out armed suspects without the use of deadly force.

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See Riot control agent#Tear gas