The use of chemical weapons during war saw its birth in WWI. By the time WWII started, every army had a gas mask designed and issued in preparation for chemical warfare.

Most of the masks around the world had the same basic design.

Brown rubberized gas mask with head straps and clear lenses. The item was carried in a brown canvas bag with shoulder straps. Issued to the different branches of the armed forces.

A common problem with gas masks is that the lenses would get fogged up from the sweat. Several anti-fog agents were created. None of them worked very effectively.