1,1,1-トリブロモ-2-メチル-2-プロパノール

Using a structure estimation method based on molecular connectivity indices(1), the Koc for 1,1,1-tribromo-2-methyl-2-propanol can be estimated to be about 7(SRC). According to a classification scheme(2), this estimated Koc value suggests that 1,1,1-tribromo-2-methyl-2-propanol is expected to have very high mobility in soil.

An estimated BCF of 13 was calculated for 1,1,1-tribromo-2-methyl-2-propanol(SRC), using an estimated log Kow of 2.35(1,SRC) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low.

The Henry's Law constant for 1,1,1-tribromo-2-methyl-2-propanol is estimated as 9.6X10-9 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 1,1,1-tribromo-2-methyl-2-propanol is expected to be essentially nonvolatile(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as >6,000 days(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as >50,000 days(SRC). 1,1,1-Tribromo-2-methyl-2-propanol's Henry's Law constant(1) indicates that volatilization from moist soil surfaces is not expected to occur(SRC). 1,1,1-Tribromo-2-methyl-2-propanol is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 0.001 mm Hg(3) determined from a fragment constant method(3).

The rate constant for the vapor-phase reaction of 1,1,1-tribromo-2-methyl-2-propanol with photochemically-produced hydroxyl radicals has been estimated as 1.17X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 14 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 1,1,1-Tribromo-2-methyl-2-propanol is not expected to directly photolyze due to the lack of absorption in the environmental spectrum(2).

1,1,1-Tribromo-2-methyl-2-propanol's production and use as a modifier in the polymerization of vinyl chloride may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 0.001 mm Hg at 25 °C indicates 1,1,1-tribromo-2-methyl-2-propanol will exist solely as a vapor in the ambient atmosphere. Vapor-phase 1,1,1-tribromo-2-methyl-2-propanol will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 14 days. If released to soil, l,1,1-tribromo-2-methyl-2-propanol is expected to have very high mobility based upon an estimated Koc of 7. The importance of biodegradation of 1,1,1-tribromo-2-methyl-2-propanol in soil and water is not known. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 9.6X10-9 atm-cu m/mole. If released into water, 1,1,1-tribromo-2-methyl-2-propanol is not expected to adsorb to suspended solids and sediment in the water column based upon the estimated Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. An estimated BCF of 13 suggests the potential for bioconcentration in aquatic organisms is low. Occupational exposure to 1,1,1-tribromo-2-methyl-2-propanol may occur through inhalation and dermal contact with this compound at workplaces where 1,1,1-tribromo-2-methyl-2-propanol is produced or used. (SRC)