Phosgene Essay Example | Topics and Well Written Essays - 1000 words

Phosgene - Essay Example At temperatures above 250oC, phosgene decomposes to mixtures of carbon monoxide (CO), chlorine gas (Cl2), carbon dioxide (CO2), and carbon tetrachloride (CCl4). Owing to its low boiling point of 7.56oC, it is very volatile and non persistent. "It may remain for long periods of time in trenches and other low lying areas" (Federation of American Scientists, 2007). Phosgene smells of newly mown hay, at room temperature. It is soluble in fatty oils and organic solvents. Its odor threshold is 0.12-5.7 ppm. And its Permissible Exposure Limit Threshold Limit value (by volume in air) is 0.1 ppm (American Chemistry Council, 2002). Physical properties of Phosgene are given below: Phosgene hydrolyses slowly in water and releases hydrochloric acid and carbon dioxide. Phosgene reacts easily with caustic solution and even more so with ammonia and ammonia water. Phosgene produces hazardous chemical reactions with certain substances. Powdered aluminum burns in the presence of the vapor of phosgene. Phosgene also reacts with alcohols. For example, with 2,4-Hexadiyne-1,6-diol, phosgene produces a shock sensitive compound 2,4-hexadiyne-1,6-bischloroformate. It also produces hazardous products on reaction with secondary amines. When phosgene is mixed with potassium and subjected to shock, it explodes (American Chemistry Council, 2002). Phosgene is a highly dangerous pulmonary toxicant. ... erg/mol cm Solubility Parameter Dipole Moment Van der Waals Volume Van der Waals Area 5.64E+04 1.16919 34.9 5.20E+09 (erg/cm3)A1/2 Debye (D) cm3/mol cm2/mol Refractive Index Flash Point Upper Flammability Limit Lower Flammability 1.35609 Unknown Unknown Unknown C vol% in air vol% in air Upper Flammability Temperature Lower Flammability Temperature Auto-Ignition Temperature Unknown Unknown Unknown C C C Density Vapor Density Vapor Pressure 1.38 (20oC) 3.4 365 (-10oC) 555 (0oC) 1173 (20oC) g/cm3 mmhg LC50 5 ppm/1h Phosgene hydrolyses slowly in water and releases hydrochloric acid and carbon dioxide. Phosgene reacts easily with caustic solution and even more so with ammonia and ammonia water. Phosgene produces hazardous chemical reactions with certain substances. Powdered aluminum burns in the presence of the vapor of phosgene. Phosgene also reacts with alcohols. For example, with 2,4-Hexadiyne-1,6-diol, phosgene produces a shock sensitive compound 2,4-hexadiyne-1,6-bischloroformate. It also produces hazardous products on reaction with secondary amines. When phosgene is mixed with potassium and subjected to shock, it explodes (American Chemistry Council, 2002). Mechanism of Injury Phosgene is a highly dangerous pulmonary toxicant. Its exposure may not produce any symptoms for a long time, and by the time symptoms are detected it usually results in fatalities. Its exposure produces massive pulmonary edema. The routes of exposure to phosgene are inhalation, and skin/eye contact. Inhalation: This is the major route of phosgene exposure. Since it is hard to detect the odor, there may be prolonged asymptomatic exposures. Phosgene also causes asphyxiation in poorly ventilated places, since it is heavier than air at temperatures above 8oC (American Chemistry