phosgene

phosgene (fŏs`jēn), colorless poison gas, first used during World War I by the Germans (1915). When dispersed in air, the gas has the odor of new-mowed hay. The gas is highly toxic; when inhaled it reacts with water in the lungs to form hydrochloric acid and carbon monoxide. Because the upper respiratory tract is little affected, warning signs of exposure are slight, and symptoms may fail to appear for from 2 to 24 hours after exposure. However, the release of hydrochloric acid in the lungs causes pulmonary edema and may also cause bronchial pneumonia and lung abscesses; in severe cases death may result within 36 hours. Phosgene is now used in chemical synthesis. It may be prepared by the reaction of carbon monoxide with chlorine in the presence of a catalyst or by the oxidation of chloroform or carbon tetrachloride. Phosgene has the formula COCl₂.

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phosgene

 or carbonyl chloride

Colourless, highly toxic gas used in chemical warfare as well as in industrial processes including the making of dyestuffs and polyurethane resins. Either alone or in combination with chlorine, it was used against troops in World War I. It smells like musty hay. Inhalation causes severe lung injury several hours after exposure. First prepared in 1811, it is manufactured by the reaction of carbon monoxide and chlorine in the presence of a catalyst. Gaseous phosgene is usually stored and transported as a liquid under pressure in steel cylinders or as a solution in toluene. Mixed with water, it forms carbon dioxide and hydrochloric acid.

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phosgene

a colourless easily liquefied poisonous gas, carbonyl chloride, with an odour resembling that of new-mown hay: used in chemical warfare as a lethal choking agent and in the manufacture of pesticides, dyes, and polyurethane resins. Formula: COCl₂