| 環境中動態 | TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 200(SRC), determined from a structure estimation method(2), indicates that perfluoroethane is expected to have moderate mobility in soil(SRC). Volatilization of perfluoroethane from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 20.3 atm-cu m/mole(3). Perfluoroethane is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 25,100 mm Hg at 25 °C(4). Biodegradation data in soil were not available(SRC, 2016).AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 200(SRC), determined from a structure estimation method(2), indicates that perfluoroethane is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 20.3 atm-cu m/mole(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 3 hours and 5 days, respectively(SRC). Perfluoroethane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). According to a classification scheme(5), an estimated BCF of 10(SRC), from its log Kow of 2.00(6) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2016).ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), perfluoroethane, which has a vapor pressure of 25,100 mm Hg at 25 °C(2), is expected to exist solely as a gas in the ambient atmosphere. Gas-phase perfluoroethane has an estimated atmospheric life-time of 500 to 10,000 years(3-5). Perfluoroethane has 20-, 100- and 500-year Global Warming Potentials of 8200, 9200-12,500 and 17,300-19,100(4-7), respectively. Perfluoroethane does not contain chromophores that absorb at wavelengths >290 nm(8) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). |
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