Tear gas used by the police to disperse the mob contains

Tear gas, formally known as a lachrymatory agent, is a possibly lethal chemical weapon that stimulates the corneal nerves in the eyes to cause tears, pain, and even blindness. The compound 2chlorobenzalmalononitrile (chemical formula: C₁₀H₅ClN₂), is the defining component of a "tear gas" commonly referred to as CS gas, which is used as a riot control agent.