The effect of Mace varies on humans. Most common is a burning sensation on the area affected with the spray. If in contact with eyes it causes automatic closing of the eyes due to intense pain if open. This along with a feeling of suffocating if inhaled it causes the person to be very vulnerable and dependent, resulting in easy overpowering (for example, law enforcement officials over a suspect). Effects can be minimal on those under the influence of alcohol or drugs. The duration of the effects vary from 30 minutes up to 2 hours, depending on the person and treatment.
Mace was originally manufactured under the name "Chemical Mace" by Lake Erie Chemical (a former division of Smith & Wesson) in 1962, but is now a registered trademark of Mace Security International. Most Mace sold today by Mace Security International is pepper spray rather than tear gas, though it is still possible to buy Mace. Many other companies now manufacture similar products.