Tear gas type is a term used to describe the type of chemical agent used in crowd control. MACE is one of the most common types of tear gas, and is a four-letter word that is often used to refer to this type of chemical agent. MACE is an aerosol spray containing a chemical irritant that causes temporary blindness, coughing, and difficulty breathing. It is used by law enforcement and military personnel to disperse crowds and subdue individuals.