Chemical warfare made its deadly debut a century ago on the European battlefields of World War I. The German army released 150 tonnes of chlorine gas at Ypres on April 22, 1915 against French soldiers. 1000 lives were lost, the ongoing story of chemical weapons is, as they say, history. Soldiers with chemical knowledge knew that a damp cloth might protect them, anything containing water would do to dampen a makeshift protective mask including solutions of sodium bicarbonate, sodium hyposulfate (a photographic fixative) and even urine. George Pollitt, a chemist working as an intelligence officer at GHQ, drafted the first instructions suggesting wetted cloths while respirators could be prepared in Britain. A workable design of pad respirator was put into production, designed by chemist Herbert Baker, of Imperial College London, based on one obtained from a German prisoner of war.