British WW2 gas mask
Imperial German troops used chlorine gas to attack the French near Ypres on April 22, 1915, marking the beginning of conventional chemical warfare. However, permeable air-filled helmets were necessary for miners, firefighters, and scuba divers long before this event.
To meet those demands, early gas mask designs were developed. The “drums,” which are made up of meshed compartments, generally include activated carbon as a primary component, which can trap most of the pollutants in the environment. This was owned by someone who was prepared to face the Axis’ worst nightmares.