The first poison gas was deployed by the French. On August 1914, the French Army fired tear-gas grenades upon the Germans.
Poison gas was introduced by the Germans in the form of Chlorine on 22 April 1915, during the second battle of Ypres. French troops noticed a yellow-green cloud coming towards the front-line, but believed it to be a mere smokescreen to cover the German attack.
Chlorine gas can cause damage to the eyes, nose, throat and lungs and if exposed for a long time death by suffocation.
The use of this deadly attack soured relations with neutral powers at the time such as the U.S. The Allies were prepared to retaliate to the German gas attacks in the form of their own chemical weapons. The British were the first to invent their own version for the Allies, firing 400 Chlorine gas shells at the German enemy at Loos on 24 September 1915.
Germany unveiled this new gas weapon in late 1917. Mustard gas was almost odourless and caused blisters, eye irritation and internal and external bleeding making it extremely deadly.
Protection from gas attacks
Soldiers were equipped with gas masks to protect themselves although in an emergency these were often hard to fix onto your face. An alternative was to urinate into a cloth and hold it against your mouth!