Answer :
Poison gas was first used by Germany in WWI with Germany employing it the most. The gases used included chlorine, mustard, and phosgene, causing severe injuries and fatalities. The devastating effects of these gases led to international bans post-war.
During World War I, poison gas was an infamous weapon used extensively by all sides involved in the conflict. Among the nations, it was Germany that first deployed poison gas against their adversaries. The variety of gases included chlorine gas, mustard gas, and phosgene. Initially, chlorine gas was used against French and Canadian troops, resulting in devastating effects on the respiratory system and leading to asphyxiation.
Mustard gas, introduced later in the war around 1917, caused severe eye irritation, blistered skin, and could lead to a slow and painful death taking weeks to unfold. Phosgene, a colorless gas, was particularly deadly, accounting for the majority of gas-related fatalities during WWI. German scientist Fritz Haber supervised the development of poisonous chlorine gas, and despite the horrendous outcomes, this warfare technology quickly spread. Ultimately, the horrific outcomes of poison gas use led to its ban in international treaties post-WWI.
