CR was developed by the British Ministry of Defence as a riot control agent in the late 1950s and early 1960s.

A report from the Porton Down laboratories described exposure as "like being thrown blindfolded into a bed of stinging nettles", and it earned the nickname "firegas".

CR is usually presented as a microparticulate solid, in the form of suspension in a propylene glycol-based liquid.

For smoke it is usually fired in canisters (LACR) that heat up, producing an aerosol cloud at a steady rate.

CR gas is a lachrymatory agent (LA), exerting its effects through activation of the TRPA1 channel.

One protester described the gas as making him feel "as if your eyes are about to fall out; then you have trouble breathing, and you lose your sight".

Mohammed ElBaradei also confirmed via Twitter that "tear gas with [a] nerve agent" is being used in Tahrir Square.

People occupying an area in Notre-Dame-des-Landes against an airport project suspect the use of CR gas by French Police and Army in April 2018.

[12] Additionally, there are British military documents now declassified and in the public domain held in the records of the UK Ministry of Defence at the National Archives, London, that suggest that the British Army did deploy and use CR gas in Northern Ireland.

[13] [14] [15] [16] [17] CR tear gas was used in suppression of the mutiny in Makati that was led by Sen. Antonio Trillanes.

[22] Also massive gas usage has been documented during demonstrations against Language Law Draft in Kyiv on 3 and 4 July 2012.