| Umweltverhalten | TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1.4X10+7(SRC), determined from a structure estimation method(2), indicates that 2,4-dinonylphenol is expected to be immobile in soil(SRC). Volatilization of 2,4-dinonylphenol from moist soil surfaces is expected(SRC), given an estimated Henry's Law constant of 6.4X10-5 atm-cu m/mole(SRC), determined using a fragment constant estimation method(3). However, adsorption to soil is expected to attenuate volatilization(SRC). 2,4-Dinonylphenol is not expected to volatilize from dry soil surfaces(SRC) based upon an extrapolated vapor pressure for the unspecified dinonylphenol isomer of 9.0X10-10 mm Hg(4). The estimated pKa of 2,4-dinonylphenol is 10.9(5), indicating that this compound will primarily exist in its unionized form in the environment(SRC). Biodegradation of 2,4-dinonylphenol may be similar to that of 4-nonylphenol(SRC), which, based on microcosm studies using six soils, was considered generally biodegradable in well-aerated arable soils(6).AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1.4X10+7(SRC), determined from a structure estimation method(2), indicates that 2,4-dinonylphenol is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 6.4X10-5 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 13 hours and 10 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column(SRC). The estimated volatilization half-life from a model pond is 1.6X10+6 years if adsorption is considered(5). The estimated pKa of 2,4-dinonylphenol is 10.9(6), indicating that this compound will primarily exist in its unionized form in the environment. According to a classification scheme(7), an estimated BCF of 3.2(SRC), from an estimated log Kow of 10.5(8) and a regression-derived equation(9), suggests the potential for bioconcentration in aquatic organisms is low(SRC). 2,4-Dinonylphenol is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(10). Biodegradation of 2,4-dinonylphenol may be similar to that of nonylphenol(SRC), which was reported to have half-lives of 58 days in seawater(11), and 28 to 104 days in mesocosm experiments using sediment(12).ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2,4-dinonylphenol, which has an extrapolated vapor pressure for the unspecified dinonylphenol isomer of 9.0X10-10 mm Hg at 25 °C(2), will exist in the particulate phase in the ambient atmosphere. Particulate-phase 2,4-dinonylphenol may be removed from the air by wet and dry deposition(SRC). 2,4-Dimethylphenol absorbs light with wavelengths >290 nm(3)by analogy 2,4-dinonylphenol may also absorb light with wavelengths >290 nm and may therefore be susceptible to direct photolysis by sunlight(SRC). |
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