phosgene


Also found in: Dictionary, Thesaurus, Medical, Acronyms, Wikipedia.
Related to phosgene: mustard gas

phosgene

(fŏs`jēn), colorless poison gaspoison gas,
any of various gases sometimes used in warfare or riot control because of their poisonous or corrosive nature. These gases may be roughly grouped according to the portal of entry into the body and their physiological effects.
..... Click the link for more information.
, 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.

Phosgene

 

(also carbonyl chloride, carbon oxychloride, chloroformyl chloride), COCl2, a colorless gas with an odor of moldy hay. Phosgene has a boiling point of 8.2°C and a melting point of – 118°C. The density of gaseous phosgene is 3.5 times that of air. Phosgene is sparingly soluble in water and freely soluble in organic solvents.

Gaseous phosgene is slowly hydrolyzed by moisture in the air; in water, hydrolysis is fairly rapid. The gas reacts with alcohols (ROH) to form chlorocarbonates (C1COOR) and carbonates (ROCOOR) and with salts of carboxylic acids to form anhydrides of the acids; it reacts with metal oxides to form halides of the metals (for example, A1C13), with ammonia to form mainly urea and NH4C1, and with amines to form arylated (alkylated) ureas CO(NHR’)2 and isocyanates. The formation of diphenylurea (R’ = C6H5), which is insoluble in water, is used in qualitative and quantitative determinations of phosgene. Phosgene reacts with dialkylanilines to form derivatives of the diphenylmethane and triphenylmethane series. The reactions described above are among the many phosgene reactions used in the commercial production of solvents, dyes, pharmaceuticals, and polycarbonates.

Phosgene is prepared by the interaction of CO and Cl2 over activated carbon.

Phosgene is highly toxic, affecting the lower reaches of the respiratory tract. It disturbs gas exchange, interferes with the oxygen supply, increases the viscosity and coagulability of the blood, and impedes circulation. Mild and moderately severe cases of acute poisoning take the form of toxic bronchitis; serious cases are accompanied by neural and psychic disorders (affective disorders, hallucinations, deafness, and, sometimes, motor excitation) and, typically, pulmonary edema. Repeated acute poisoning can result in asthenia, chronic bronchitis, pneumonia, pleurisy, and, eventually, bronchiectasis, pulmonary abscess, and gangrene of the lungs. First aid includes the administration of oxygen for an extended period, intravenous injection of solutions of calcium chloride and glucose, and washing of the mucosa with a 2-percent solution of sodium bicarbonate. Safety measures include the hermetic sealing of equipment, the use of gas masks and protective clothing, and the ventilation of work areas.

During World War I, phosgene was used as a choking war gas. Concentrations of the order of 0.005 mg/liter are dangerous, and concentrations of 0.1–0.3 mg/liter cause death within 15 min. Phosgene poisoning manifests itself only after a delay of 2–12 hours. Gas masks are used for protection.

R. N. STERLIN and A. A. KASPAROV

phosgene

[′fäz‚jēn]
(organic chemistry)
COCl2 A highly toxic, colorless gas that condenses at 0°C to a fuming liquid; used as a war gas and in manufacture of organic compounds.

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
References in periodicals archive ?
RELEVANCE TO CLINICAL PRACTICE: The acute transient hematologic effects observed in the exposed residents were associated with the incident of leakage of mixed fire-extinguisher gases and were most likely caused by a small amount of pyrolytic products, probably phosgene.
While the schedules may imply that Schedule 3 is not particularly threatening, one of the first and most deadly chemical weapons, phosgene, is a Schedule 3 chemical.
It can detect chemicals such as hydrogen cyanide, phosgene, sulfur dioxide, and chlorine in addition to narcotics and explosives, and it can analyze both vapor and particle samples.
These include two carcinogens, two global pollutants, a chemical warfare agent known as PFIB and a chemical analog of the World War II nerve gas phosgene, according to the Environmental Working Group.
The man, who described himself as a 'casually employed civil servant in the counter proliferation and arms control department', said he had advised toning down a passage in the dossier on the al-Qa'qa plant which manufactured the chemical phosgene.
Department of Health and the FBI have warned that terrorists might disperse such easy-to-get chemicals as chlorine, used to bleach paper and purify water; phosgene, used in dyes; and hydrogen cyanide, used in some pesticides.
It is made from phosgene (which was used as a poison gas in the First World War) and Bisphenol A (an endocrine disruptor).
For the cyclization (carbonylation) of secondary amine 3 we tried to use dimethyl carbonate, which is a non-hazardous phosgene alternative [8, pp.
Of these, chlorine gas and phosgene exhibit their toxicity in the form of acute pulmonary edema accompanied by irritation of the nose, larynx, pharynx, trachea, and bronchi (34).
Three chemicals -- propylene chlorohydrin, phosgene and epichlorohydrin -- account for the vast majority of chlorine use for chemical intermediates (chemicals used to make other products).
Among the highly toxic chemicals released during the Pancevo bombing were: vinyl chloride, a carcinogen that can cause damage to the kidneys and the nervous system as well as damage a developing fetus; ethylene dichloride, a carcinogen that can cause liver and kidney damage; and, perhaps most insidious, phosgene, a deadly substance which was used as a chemical weapon in World War I.
In the past it has been used as an industrial solvent and the poison phosgene gas it produces was even used by the Germans in World War One to attack enemy troops.