(2-ブロモエチル)ベンゼン

TERRESTRIAL FATE: (2-Bromoethyl)benzene will have low mobility(3) in soil based on estimated Koc values of 581.6 and 955(1,2,SRC). Insufficient data are available to determine the rate or importance of biodegradation of (2-bromoethyl)benzene in soil conditions. Volatilization of (2-bromoethyl)benzene is expected from moist and dry soils based on an experimental vapor pressure of 0.2445 mm Hg at 25 °C(4) and an Henry's Law constant of 1.52X10-3 atm cu m/mole estimated from an experimental water solubility of 39.05 mg/l(4) and a vapor pressure of 0.2445 mm Hg(4).

AQUATIC FATE: (2-Bromoethyl)benzene is expected to volatilize rapidly from water(1) based upon an estimated Henry's Law constant of 1.52X10-3 atm cu m/mol estimated from an experimental water solubility of 39.05 mg/L(2) and a vapor pressure of 0.2445 mm Hg(2). Based on this Henry's Law constant the volatilization half-life from a model river (1 meter deep flowing 1 m/sec with a wind velocity of 3 m/sec) can be estimated to be about 4.8 hours(1,SRC). The volatilization half-life from a model lake (1 meter deep) can be estimated to be about 5.6 days(1,SRC). Insufficient data are available to determine the rate or importance of biodegradation of (2-bromoethyl)benzene in aquatic conditions(SRC). Aquatic bioconcentration and adsorption to sediment may be important fate processes in aquatic systems based on an estimated BCF of 78(1,SRC) and estimated Koc values of 582 and 955(1,3,SRC) but hydrolysis is not expected to be important(SRC).

ATMOSPHERIC FATE: Based on an experimental vapor pressure of 0.2445 mm Hg at 25 °C(1), (2-bromoethyl)benzene will exist in the atmosphere in the vapor phase(2). It will degrade in the atmosphere by reaction with photochemically produced hydroxyl radicals with an estimated half-life of 2.87 days(3). Removal of (2-bromoethyl)benzene from the atmosphere can occur through wet deposition(SRC).

Using a structure estimation method based on molecular connectivity indices, the Koc for (2-bromoethyl)benzene can be estimated to be about 955(1). The Koc for (2-bromoethyl)benzene can also be estimated to be about 582 based on an experimental water solubility of 39.05 mg/l(3) and a regression derived equation(2). According to a suggested classification scheme(4), these estimated Koc values suggest that (2-bromoethyl)benzene has low soil mobility.

2-Bromoethylbenzene (CAS # 103-62-9) was evaluated for acute oral toxicity. The test substance was administered once orally, by gavage to groups of male and female fasted albino rats. Dosage and mortality data are as follows: 521 mg/kg (0/5 M, 0/5 F); 750 mg/kg (2/5 M, 2/5 F); and 1080 mg/kg (5/5 M, 4/5 F). All deaths occurred within 7 days of dosing. The combined LD50 value was determined to be 811 mg/kg. At 521 mg/kg and above, treatment-related toxicity included hypoactivity and salivation; at 750 mg/kg and above, ataxia, clear ocular discharge and labored breathing were seen. There also was a low incidence of urogenital staining, abnormal defecation, dry brown staining around nose, hypothermia, dried red material around the eye(s), prostration and rales. There were no treatment-related changes in body weights. Necropsy of rats that died revealed external matting, dark red or reddened adrenal glands, stomach abnormalities, hemorrhagic thymus glands, and intestinal abnormalities.

(2-Bromoethyl)benzene's use as a starting material for the production of various beta-phenethyl derivatives, pharmaceuticals, fragrances, and other fine chemicals(1) could result in its release to the environment through various waste streams(SRC).

Based upon an experimental water solubility of 39.05 mg/l(1), the BCF of (2-bromoethyl)benzene can be estimated to be approximately 78 from a regression-derived equation(2). This estimated BCF value suggests that bioconcentration in aquatic organisms may be an important fate process(SRC).

The Henry's Law constant for (2-bromoethyl)benzene can be estimated to be 1.52X10-3 atm-cu m/mole based on an experimental water solubility of 39.05(1) and an experimental vapor pressure of 0.2445(1). This value of the Henry's Law constant indicates that volatilization of (2-bromoethyl)benzene from water is rapid(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 meter deep flowing 1 m/sec with a wind velocity of 3 m/sec) can be estimated to be about 4.8 hours(2,SRC). The volatilization half-life from a model lake (1 meter deep) can be estimated to be about 5.6 days(2,SRC).

The rate constant for the vapor-phase reaction of (2- bromoethyl)benzene with photochemically produced hydroxyl radicals has been estimated to be approximately 5.59X10-12 cu cm/molecule-sec at 25 °C, which corresponds to an atmospheric half-life of about 2.9 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1,SRC).

(2-Bromoethyl)benzene's use as an starting material for the production of various beta-phenethyl derivatives, pharmaceuticals, and fragrances could result in its release to the environment through various waste streams. (2-Bromoethyl)benzene should have low mobility in soil. Volatilization of (2-bromoethyl)benzene is expected from both moist and dry soils. In water, (2-bromoethyl)benzene is expected to volatilize rapidly with estimated half-lives of 4.8 hours and 5.6 days from a model river and a model lake, respectively. Bioconcentration and adsorption to sediment may be important fate processes in aquatic systems, but hydrolysis is not expected to be important. Insufficient data are available to determine the rate or importance of biodegradation of (2-bromoethyl)benzene in either soil or aquatic conditions. (2-Bromoethyl)benzene will exist in the vapor phase in the ambient atmosphere. If released to the atmosphere, it will degrade by reaction with photochemically produced hydroxyl radicals with an estimated half-life of approximately 2.9 days. Removal of (2-bromoethyl)benzene from the atmosphere can occur through wet deposition. Exposure to (2-bromoethyl)benzene can occur through dermal contact, inhalation, and ingestion. (SRC)