The United States has destroyed the last of its declared chemical weapons stockpile, a White House statement said on July 7.
The US had a September 30 deadline to eliminate its remaining chemical weapons under the international Chemical Weapons Convention. These weapons were first used in modern warfare in World War I, when they were estimated to have killed at least 100,000 people, by Iraq during its conflict with Iran in the 1980s, and in the Syrian war.
US workers at the Army Pueblo Chemical Depot in southern Colorado began destroying chemical weapons in 2016, and on June 22, completed their mission of neutralising about 2,600 tonnes of mustard blister agent.
In the 1980s, the Army planned to incinerate 520 tonnes of chemical weapons at Kentucky’s Blue Grass Army Depot, but the community around opposed. It led to a decades-long battle over how these weapons would be disposed of. It began destroying these weapons in 2019, through neutralisation, by diluting the deadly agents so they could be safely disposed of.
To dispose of the mustard blister agent, robotic equipment removed the weapons’ fuses and bursters before the agent was neutralised with hot water and mixed with a corrosive solution to prevent the reaction from reversing. The byproduct was further broken down by microbes, and the mortars and projectiles were decontaminated at 538 degrees Celsius and recycled as scrap metal. Leaky or overpacked munitions were sent to an armoured, stainless steel detonation chamber to be destroyed at high temperatures.
