Formula of the Tear Gas used by police?

Question

(Preferably in India)

Answer 1

Tear gas is actually the common term for a family of chemical compounds that have been otherwise referred to as "harassing agents" because of their ability to cause temporary disablement. Some 15 chemicals have been used worldwide as tear gas agents. Four of these--w-chloroacetophenone (CN), o-chlorobenzylidenemalononitrile (CS), 10-chloro-5, 10-dihydrophenarsazine, and x-bromo-x-tolunitrile-have been used extensively (1). In the United States, Britain, and Europe, CN and CS have been employed most widely. O-Chlorobenzylidenemalononitrile, in particualr, is a weapon that has gained widespread acceptance as a means of controlling civilian populations during disturbances.

As far as I know, the Indian Police buy much of its supplies from either the USA or the UK.

Answer 2

CS or 2-chlorobenzalmalononitrile (chemical formula: C10H5ClN2) is a substance that is used as a riot control agent and is usually claimed to be non-lethal by the forces who use it. CS was discovered by two Americans, Ben Carson and Roger Staughton in 1928, the first letters of the scientists' surnames giving us the name of the substance, 'CS' [4]. It was developed and tested secretly at Porton Down in Wiltshire, England. Apparently this testing occurred in the 1950s and 1960s when CS was used firstly on animals, then subsequently on British Army servicemen volunteers. Notably CS has a limited effect on animals due to "under-developed tear-ducts and protection by fur"

Answer 3

Tear gases are a generic term.
They include gases as
CS or 2-chlorobenzalmalononitrile (chemical formula: C10H5ClN2)
http://en.wikipedia.org/wiki/CS_gas
CN or chloroacetophenone (chemical formula C8H13ClO)
http://en.wikipedia.org/wiki/CN_gas
CR gas or dibenzoxazepine (chemical formula C13H9NO)
http://en.wikipedia.org/wiki/CR_gas

Nowadays the first one is used most.