CN gas is a powerful and highly dangerous substance used in riot control and crowd dispersal situations. Synonyms for CN gas include tear gas, mace, pepper spray, and chloroacetophenone. Tear gas is the most commonly known synonym and is often used interchangeably with CN gas. Mace is another popular synonym that refers to a particular brand that produces tear gas sprays. Pepper spray is a modern form of tear gas and is made with capsaicin, a spicy ingredient found in chili peppers. Chloroacetophenone is a chemical compound that is used in CN gas and is responsible for its intense irritant effects on the eyes, skin, and respiratory system.