Enlisted men wearing box respirators while playing baseball. U.S. Army. Signal Corps photo, 1918. The gas mask is used to protect the wearer from inhaling 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 British Royal Society of Chemistry claims that British scientist Edward Harrison developed the first practical gas mask for mass production towards the end of 1916. American chemist and inventor James Bert Garner is credited by American sources with the invention of the gas mask in April 1915. He remembered experiments he had performed while teaching at the University of Chicago. He created the first gas mask which he tested on two of his associates in a gas filled chamber. Following the successful completion of the test, he provided the results to the British government.