Phosgene, COCL2, also known as carbonyl chloride and chlorofonnyl chloride, is a colorless,poisonous gas produced by the action of chlorine and carbon monoxide. It condenses at 0 °C (32 OF) to a fuming liquid. Phosgene was used as a war gas, but is now used in the production of metal chlorides, pharmaceuticals, isocyanate resins,and perfumes. Phosgene (CG) is a colorless gas above 8.2C. Fog-like when concentrated. Colorless, fuming liquid below 8.2C. May have the appearance of a white cloud.