CS gas, also known as tear gas, is a chemical compound used primarily for crowd control and self-defense. It causes temporary irritation to the eyes, skin, and respiratory system, leading to tearing, coughing, and difficulty breathing. CS gas is often deployed by law enforcement during riots or protests to disperse crowds. The active ingredient in CS gas is ortho-chlorobenzylidene malononitrile, which is a synthetic compound. While it is effective in incapacitating individuals temporarily, exposure can lead to more severe health issues, especially for those with pre-existing respiratory conditions. Proper safety measures are essential when using or encountering CS gas.