| Umweltverhalten | TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 3.7X10+3(SRC), determined from a log Kow of 4.03(2) and a regression-derived equation(3), indicates that 4-(1,1-dimethylpropyl)phenol is expected to have slight mobility in soil(SRC). Volatilization of 4-(1,1-dimethylpropyl)phenol from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.0X10-6 atm-cu m/mole(4), derived from its vapor pressure, 2.00X10-3 mm Hg(5), and water solubility, 1.68X10+2 mg/L(6). 4-(1,1-Dimethylpropyl)phenol is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(5). Biodegradation data for 4-(1,1-dimethylpropyl)phenol in the terrestrial environment were not available(SRC, 2009).AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 3.7X10+3(SRC), determined from a log Kow of 4.03(2) and a regression-derived equation(3), indicates that 4-(1,1-dimethylpropyl)phenol is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(4) based upon an estimated Henry's Law constant of 2.0X10-6 atm-cu m/mole(5), derived from its vapor pressure, 2.00X10-3 mm Hg(6), and water solubility, 1.68X10+2 mg/L(7). Using this Henry's Law constant and an estimation method(4), volatilization half-lives for a model river and model lake are 18 and 140 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The estimated volatilization half-life from a model pond is 87 months if adsorption is considered (8). According to a classification scheme(9), an estimated BCF of 210(SRC), from its log Kow(2) and a regression-derived equation(10), suggests the potential for bioconcentration in aquatic organisms is high(SRC). Biodegradation data for 4-(1,1-dimethylpropyl)phenol in the aquatic environment were not available(SRC, 2009).ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 4-(1,1-dimethylpropyl)phenol, which has a vapor pressure of 2.00X10-3 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 4-(1,1-dimethylpropyl)phenol 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 9.2 hours(SRC), calculated from its rate constant of 4.2X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Reaction with atmospheric nitrate radicals may be important(3)rate constants of phenols and alkyl phenols for reaction with NO3 radicals range from 1.37X10-11 to 3.92X10-12 cu cm/mole sec(5) which correspond to half-lives of 12.3 min to 3.5 min at an evening concentration of 2.4X10+8 nitrate radicals per cu cm(6). 4-(1,1-Dimethylpropyl)phenol contains chromophores that absorb at wavelengths >290 nm(4) and therefore may be susceptible to direct photolysis by sunlight(SRC). |
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