The First World War is often marked as one of the first instances of chemical warfare. On April 22, 1915, the Germany Army used chlorine gas at the Battle of Ypres. Although very few people died, the news of this started widespread panic, and gas masks became a common part of the soldier’s equipment. Both sides of the war used gas as a weapon; although it was not always safe: when the wind changed direction, gas could be against you!
There are three main types of poison gas used in the Great War: Chlorine, a smelly and irritating gas that would burn your respiratory system and could lead to suffocation; phosgene gas, which was like chlorine gas but caused less coughing and was therefore less detectable and more likely to be inhaled; and mustard gas, the cause of waterng eyes, burning of the throat and lungs and blistering skin. All three are highly undetectable, and caused much fear during the war.