A gas mask is a mask put on over the face to shield the wearer from breathing airborne pollutants and toxic gases. The mask forms a sealed cover over the nose and mouth, but may also cover the eyes and other vulnerable soft tissues of the face.
Some gas masks are also respirators, though the word gas mask is often used to refer to military equipment. The user of the gas mask is not protected from gas that the skin can absorb. Airborne toxic materials may be gaseous or particulate. Many gas masks include protection from both types.
Gas masks are used in construction to protect against welding fumes, in deconstruction to protect against asbestos or other hazardous particles, and in the chemical industry when handling hazardous materials, as in making repairs to leaking equipment or cleaning after spills; workers are usually issued gas masks as a precaution against leaks.
During riots where tear gas is employed by riot police, gas masks are commonly used by police and rioters alike. Aside from serving their functional purposes, gas masks are also used as emblems in industrial music, by graffiti taggers because the mask protects them from the graffiti canister’s toxic fumes, and by Urban, Explorers venturing into environments where hazardous materials, such as asbestos, may be present.