| Umweltverhalten | TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 710(SRC), determined from a structure estimation method(2), indicates that m-xylyl bromide is expected to have moderate mobility in soil(SRC). Volatilization of m-xylyl bromide from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 7.6X10-5 atm-cu m/mole(SRC), using a fragment constant estimation method(3). m-xylyl bromide is expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 0.15 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). However, based on hydrolysis half-lives of 3.4 hours and 4.3 minutes for the o- and p-isomers, respectively(4), adsorption, volatilization, bioconcentration, and biodegradation are not expected to be important environmental fate processes in moist soil(SRC).AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 710(SRC), determined from a structure estimation method(2), indicates that m-xylyl bromide 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 7.6X10-4 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 6 hrs and 6 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 85(SRC), from an estimated log Kow of 3.43(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). However, based on hydrolysis half-lives of 3.4 hours and 4.3 minutes for the o- and p-isomers, respectively(6), adsorption, volatilization, bioconcentration, and biodegradation are not expected to be important environmental fate processes in water(SRC).ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), m-xylyl bromide, which has an estimated vapor pressure of 0.15 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase m-xylyl bromide 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 4.3 days(SRC), calculated from its rate constant of 3.7X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(2). m-Xylyl bromide does not contain chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). |
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