Carbonyl chloride is a chemical compound with the formula COCl2. It’s also known as phosgene and it has an irritating odor similar to hydrogen cyanide (HCN). Carbonyl chloride exists in two forms: gaseous form at room temperature or solid form under pressure. In its liquid state, carbonyl chloride appears colorless or slightly yellowish. This substance reacts readily with water producing carbon dioxide gas (CO2) and hydrochloric acid (HCl), which can cause severe burns when exposed directly on skin or eyes. It finds use mainly in organic synthesis reactions where it acts as a source of “CO” for various transformations like forming esters from alcohols, preparing ureas from amines etc. Additionally, it serves as a precursor for many other important industrial products such as polyurethanes, pesticides, herbicides among others.