What chemical is used for tear gas?

Tear gas, used for riot control and crowd dispersal, primarily employs several chemical agents. The most common ones are:

1. CS Gas (2-Chlorobenzalmalononitrile):

• Chemical Formula: C₁₀H₅ClN₂.

• Developed in 1928 by Ben Corson and Roger Stoughton (hence "CS").

• Widely used today due to its potent effects and relatively low toxicity. It causes intense eye, skin, and respiratory irritation by activating the TRPA1 pain receptor.

2. CN Gas (Chloroacetophenone):

• Chemical Formula: C₈H₇ClO.

• An older agent, once used in products like "Mace." Less common now due to higher toxicity compared to CS.

3. CR Gas (Dibenzoxazepine):

• Chemical Formula: C₁₃H₉NO.

• Less frequently used but causes similar irritant effects. It is a solid compound dispersed as an aerosol.

Additional Notes:

• These agents are typically deployed as aerosols or powders, causing temporary lacrimation (tearing), coughing, and skin burning.

• CS is the most prevalent in modern use, while CN has declined due to safety concerns.

• Effects are generally reversible, though exposure in confined spaces or to high concentrations can pose serious health risks.

Always handle such chemicals with extreme caution, as their use is regulated under international law.