Tear Gas
. Tear Gas, chemical substance that produces a primary physical effect of stinging or tearing eyes. Tear gas also irritates other mucous membranes and causes choking and coughing. People exposed to higher concentrations may experience burning, itching, or even blistering skin. As a form of riot control, police often use clouds of tear gas to break up crowds of people. A rifle-fired grenade or a thrown canister usually delivers tear gas, but smaller hand-held spray devices also exist. Tear gas may also be used to force the surrender of fugitives hiding in a building. Dogs and horses are relatively unaffected by tear gas, so they can add to the riot-control effect of the gas. TYPES OF TEAR GAS CN and CS are the two main types of tear gas. CN’s scientific name is chloroacetophenone, and it comes in several variants. CNB adds benzene and carbon tetrachloride, while CNC adds chloroform. CNS adds chloropicrin (PS), which can cause victims to vomit or suffer lung damage. CN was discovered in