British troops wearing gas masks in the trenches, Salonika, 1917

Photograph, World War One, Salonika (1914-1918), 1917.

The introduction of gas warfare in 1915 created an urgent need for protective equipment to counter its effects. The British Army therefore developed a range of gas helmets based on fabric bags and hoods that had been treated with anti-gas chemicals (as in this photograph). Improvements continued to be made and by the middle of 1916 the small box filter respirator was in circulation. This design gave protection against the different gases then in use.