Unable to break the stalemate on the Western Front using conventional weaponry, the German High Command took the decision on 22 April 1915 to deploy poison gas in order to clear a gap in the Allied line. At this stage, the weaponization of gas involved its release into the wind, thereby driving the toxin into enemy positions. As this method proved to be too dependent on weather conditions, gas-filled artillery shells were developed which could be delivered with greater precision. The gas war reached its peak in 1918, with an estimated one in three shells fired at the time containing poisonous chemicals.

A total of 45 different toxic agents were used by the Allies and the Central Powers in the search for the most effective weapon. Regardless of the gas used, the consequences involved were always horrific. First, gassed soldiers suffered a painful irritation of the respiratory tract and eyes, followed by chemical reactions in the body that led to massive difficulty breathing, and often to the lungs filling with fluid, which proved fatal. Certain gas mixtures could also penetrate clothing and caused severe skin irritation and burns.