Canister for storing a WWII German gas mask, found in a barn outside Ste. Mere-Eglise, France. Although poison gas had been used to inflict over 800,000 battlefield casualties in World War I, during World War II it was never used in combat. However, both sides carried gas masks and protective clothing, just in case. Often, late in war, German soldiers carried extra food in the metal canisters originally designed for carrying their gas masks.