The Deadly History of Diphosgene: A Colorless, Highly Toxic Gas Used as a Chemical Weapon

Diphosgene is a colorless, highly toxic gas with a pungent odor, which was used as a chemical weapon during World War I. It is a mixture of two phosphorus compounds: phosgene and carbonyl chloride.

Phosgene (COCl2) is a highly toxic gas that was first synthesized in 1812 by the French chemist Claude-Louis Berthollet. It was used as a chemical weapon during World War I, causing severe respiratory and pulmonary edema in soldiers exposed to it. Phosgene is a potent nerve agent that can cause death within minutes of exposure.

Carbonyl chloride (COCl2) is another highly toxic gas that was also used as a chemical weapon during World War I. It is similar to phosgene in its effects on the human body, causing severe respiratory and pulmonary edema.

Diphosgene is a mixture of these two gases, with a ratio of 1:1 or 2:1 (phosgene:carbonyl chloride). It was used as a chemical weapon because it is more stable than phosgene and can be stored for longer periods of time without degrading. However, diphosgene is just as toxic as phosgene and carbonyl chloride, and exposure to it can cause the same severe respiratory and pulmonary edema effects.

Today, the use of diphosgene and other chemical weapons is banned by international law, and efforts are being made to destroy existing stockpiles of these weapons. However, the threat of their use still exists, and it is important for military personnel and first responders to be trained in the handling and treatment of victims of chemical weapon attacks.