Pepper spray, oleoresin capsicum spray, OC spray, capsaicin spray, mace, or capsicum spray is a lachrymator (tear gas) product containing as its active ingredient the chemical compound capsaicin, which irritates the eyes with burning and pain sensations and so causes them to close, bringing temporary blindness. This blindness allows officers to more easily restrain subjects and permits people in danger to use pepper spray in self-defense for an opportunity to escape. It also causes temporary discomfort and burning of the lungs which causes shortness of breath. Pepper spray is used as a less lethal weapon in policing, riot control, crowd control, and self-defense, including defense against dogs and bears.
Pepper spray was engineered originally for defense against bears, cougars, wolves, and other dangerous predators, and is often referred to colloquially as bear spray.