How many gas masks were made during ww1?

During World War I, it is estimated that over 1.5 million gas masks were produced by the end of the conflict. The masks were developed in response to the widespread use of chemical weapons on the battlefield. Various countries, including the United States, Britain, and Germany, manufactured different designs to protect soldiers from harmful gases like chlorine and mustard gas. The production of gas masks became essential as the war progressed and chemical warfare tactics evolved.