CClCO

CClCO, or carbonyl chloride, is a chemical compound with the formula Cl₂C=O. It is commonly known as phosgene, a colorless gas with a faint, sweet odor, though its smell is often described as unpleasant at higher concentrations. Phosgene was first identified in 1812 by the French chemist Joseph-Louis Gay-Lussac, who synthesized it by reacting chlorine gas with carbon monoxide. It gained notoriety during World War I as a chemical warfare agent due to its high toxicity and ability to cause severe respiratory distress.

Phosgene is highly reactive and serves as an important intermediate in organic synthesis. It is primarily used in the production of isocyanates, which are key components in the manufacture of polyurethane foams, adhesives, and coatings. The compound is also employed in the synthesis of pharmaceuticals, agrochemicals, and other specialty chemicals. Industrially, phosgene is typically generated in situ to minimize exposure risks, as it is highly hazardous under uncontrolled conditions.

The toxicity of phosgene arises from its ability to react with water in the lungs, forming hydrochloric acid and carbon dioxide. This reaction damages lung tissue, leading to symptoms such as coughing, chest pain, and pulmonary edema. Exposure to even low concentrations can be lethal, particularly over prolonged periods. Due to its dangers, strict safety protocols and containment measures are required in its handling and production.

Phosgene is regulated under international chemical weapons conventions, such as the Chemical Weapons Convention (CWC), which prohibits its use as a warfare agent. Despite its hazardous nature, its industrial applications remain significant, driving ongoing research into safer alternatives and improved safety technologies.