Acrylonitrile

CAS RN:107-13-1

Environmental Fate

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 29(SRC), determined from a log Kow of 0.25(2) and a regression-derived equation(3), indicates that acrylonitrile is expected to have very high mobility in soil(SRC). Volatilization of acrylonitrile from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 1.38X10-4 atm-cu m/mole(4). Acrylonitrile is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 109 mm Hg at 25 deg C(5). Complete biodegradation of a low concentration of acrylonitrile was <2 days to 6 days depending on soil type with slow degradation reported in unacclimated soils exposed to high concentrations of acrylonitrile(6); these findings suggest that biodegradation may be an important environmental fate process in soil under certain conditions(SRC).
AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 29(SRC), determined from a log Kow of 0.25(2) and a regression-derived equation(3), indicates that acrylonitrile is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(4) based upon a Henry's Law constant of 1.38X10-4 atm-cu m/mole(5). Using this Henry's Law constant and an estimation method(4), volatilization half-lives for a model river and model lake are 7 hrs and 4 days, respectively(SRC). According to a classification scheme(6), a BCF of 48(7) suggests bioconcentration in aquatic organisms is moderate(SRC). Acrylonitrile was stable to aqueous hydrolysis in the pH range of 4-10 over a 10-day observation period(8) suggesting that hydrolyis is not important under environmental conditions (pH 5 to 9). Complete degradation in 6-20 days using various freshwater inoculums(8,9) suggests that biodegradation may be an important environmental fate process in water(SRC).
ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), acrylonitrile, which has a vapor pressure of 109 mm Hg at 25 deg C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase acrylonitrile is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 1.5 hours(SRC), calculated from its rate constant of 1.11X10-11 cu cm/molecule-sec at 25 deg C(3). The half-life for reaction with ozone in air is estimated to be 83 days(SRC), calculated from its rate constant of 1.38X10-19 cu cm/molecule-sec at 25 deg C(4). Acrylonitrile does not absorb UV light at wavelengths >290 nm(5) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).
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