Poison gas was one of the biggest, and the most deadly, weapons of World War I. It was considered uncivilized prior to the war, but it was used to help overcome the stalemate, or deadlock, that occurred during trench warfare. This page will outline the history, and the different types of poison gas that were used during the war.
Although poison gas was believed to be first used by the Germans, the French first used tear gas grenades (xylyl bromide) against the Germans in August 1914. This was the first month of the war. However, the Germans were the first to put major time and effort into the development of poison gas. Starting in October 1914, the Germans fired chemical irritantsat the French that made them sneeze. The Germans first used tear gas in 1915 on the Eastern Front. Other gases followed as time went on; I will continue explaining the history when I describe each of the individual gases.
Chlorine gas was first used by the Germans at the Second Battle of Ypres on April 22, 1915. That morning, the Allies went about 5 miles into German territory. The Germans then bombarded the Allied trenches, and then the activity slowed. That evening, the Germans bombarded more chlorine gas, and the Allies didn't know what to do, so they got ready to fire within their trenches. An infantry attack did not come later that day following the attack. The yellow-green gas produced major effects; it destroyed the soldiers' respiratory organs, and it caused them to violently choke. As revenge for this attack, the British produced chlorine gas, which they released upon the Germans on September 24, 1915, at the battle of Loos. However, due to their delivery method, most of the gas blew back into their trenches, and it was believed that the British suffered more casualties than the Germans did.
Above: The first chlorine attack at the Second Battle of Ypres, April 22, 1915.
Phosgene gas followed chlorine gas in the Great War. It was colorless and odorless, so soldiers inhaled more of it. Due to this fact, it was more deadly than chlorine gas. Phosgene gas solved all of the problems of chlorine gas; there were no problems with delivery, or backfiring. One interesting fact about phosgene gas was the time that it took to effect the soldiers. A soldier could have shown no symptoms of phosgene gas poisoning until 48 hours after he inhaled it. It was used by both the Germans and the Allies. Although it was sometimes used on its own, the Allies mixed an equal amount of chlorine gas and phosgene gas to form what they called "white star." The denser phosgene gas helped spread the chlorine gas, making it a very effective mixture. The "white star" gas was commonly used at the Battle of the Somme. In all, phosgene gas accounted for 85% of the poison gas deaths of the war, which was more than mustard gas.
An uncovered phosgene gas tube found at the Somme in 2006 (above).
Mustard gas was the most widely reported poisonous gas of World War I, although it was not the most deadly. It was introduced by the Germans against the Russians at the battle of Riga in 1917. Mustard gas was only fatal in high doses, so it was mainly used to taunt and disable the enemy. It caused severe internal and external bruising, as well as internal and external bleeding. Mustard gas victims took a long time to recover. Another benefit of mustard gas was that it was nearly odorless, so it was hard to discover, and protection against it was much harder than chlorine gas or phosgene gas. There was one serious drawback of mustard gas, however. If, let's say, the Germans fired mustard gas at the British, and they wanted to take over the British's trench, they could get poisoned as well. This was because mustard gas stayed in the soil for weeks, and it kept the same effects. At first, the Germans propelled in the production of mustard gas, but the Allies then took the lead. This was due to the fact that the United States entered the war in 1917, and they had many opportunities for production.
A Canadian soldier with mustard gas burns around 1917 and 1918 (above).