BROMOFORM

Note: Bromoform may be stabilized with ethanol (≤ 3 %). CASRN: 75-25-2; DOT: 2515; DOT label: Poison; molecular formula: CHBr3; FW: 252.73; RTECS: PB5600000; Merck Index: 12, 1441 Physical state, color, and odor: Clear, colorless to yellow liquid with a chloroform-like odor. Odor threshold concentration in water is 0.3 mg/kg (Verschueren, 1982). Melting point (°C): 8.3 (Weast, 1986) Boiling point (°C): 149.5 (Weast, 1986) Density (g/cm3): 2.89165 at 20 °C (Kudchadker et al., 1979) 2.8788 at 25.00 °C, 2.8659 at 30.00 °C, 2.8530 at 35.00 °C (Aminabhavi and Patil, 1998) Diffusivity in water (x 10-5 cm2/sec): 0.95 at 20 °C using method of Hayduk and Laudie (1974) Flash point (°C): Noncombustible liquid (NIOSH, 1997) Lower explosive limit (%): Not applicable (NIOSH, 1997) Upper explosive limit (%): Not applicable (NIOSH, 1997) Henry’s law constant (x 10-4 atm⋅m3/mol): 4.3 at 20 °C (Nicholson et al., 1984) 4, 7, and 12 at 20, 30, and 40 °C, respectively (Tse et al., 1992) In seawater (salinity 30.4‰): 1.41, 2.88, and 5.22 at 0, 10, and 20 °C, respectively (Moore et al.,

1995) 5.32 at 25 °C (gas stripping-GC, Warner et al., 1987) 4.31 at 20.00 °C (inert gas stripping, Hovorka and Dohnal, 1997) 2.33, 4.09, and 6.93 at 10, 20, and 30 °C, respectively (multiple equilibriation-GC, Munz and

Roberts, 1987) 3.36 at 20.0 °C, 7.09 at 35.0 °C, 20.5 at 50.0 °C (equilibrium static cell, Wright et al., 1992) Interfacial tension with water (dyn/cm at 20 °C): 40.85 (Demond and Lindner, 1993)

10.51 ± 0.02 (Franklin et al., 1969) Soil organic carbon/water partition coefficient, log Koc: 2.45 (Abdul et al., 1987) 2.10 (Hutzler et al., 1986) Octanol/water partition coefficient, log Kow: 2.30 (quoted, Mills et al., 1985) 2.38 (quoted, Valsaraj, 1988) Solubility in organics: Soluble in ligroin (Weast, 1986). Miscible with benzene, chloroform, ether, petroleum ether, acetone, and oils (Windholz et al., 1983). Solubility in water: 3,010 mg/kg at 15 °C, 3,190 mg/kg at 30 °C (shake flask-interferometer, Gross and Saylor, 1931) 3,130 mg/L at 25 °C (quoted, Valsaraj, 1988) 3,931 mg/L at 30 °C (vapor equilibrium-GC, McNally and Grob, 1984) 3,180 mg/L at 30 °C (quoted, Horvath, 1982) Vapor density: 10.33 g/L at 25 °C, 8.72 (air = 1) Vapor pressure (mmHg): 4 at 20 °C (quoted, Munz and Roberts, 1987) 5.4 at 25 °C (quoted, Mackay et al., 1982) Environmental fate: Biological. Bromoform showed significant degradation with gradual adaptation in a staticculture flask-screening test (settled domestic wastewater inoculum) conducted at 25 °C. At concentrations of 5 and 10 mg/L, percent losses after 4 wk of incubation were 48 and 35, respectively (Tabak et al., 1981). Surface Water. Kaczmar et al. (1984) estimated the volatilization half-life of bromoform from rivers and streams to be 65.6 d. Chemical/Physical. The estimated hydrolysis half-life in water at 25 °C and pH 7 is 686 yr (Mabey and Mill, 1978). Products of hydrolysis include carbon monoxide and hydrobromic acid (Kollig, 1993). When an aqueous solution containing bromoform was purged with hydrogen for 24 h, only 5% of the bromoform reacted to form methane and minor traces of ethane. In the presence of colloidal platinum catalyst, the reaction proceeded at a much faster rate forming the same end products (Wang et al., 1988). In an earlier study, water containing 2,000 ng/µL of bromoform and colloidal platinum catalyst was irradiated with UV light. After 20 h, about 50% of the bromoform had reacted. A duplicate experiment was performed but the concentration of bromoform was increased to 3,000 ng/µL and 0.1 g zinc was added. After 14 h, only 0.1 ng/µL bromoform remained. Anticipated transformation products include methane and bromide ions (Wang and Tan, 1988). Photolysis of an aqueous solution containing bromoform (989 µmol) and a catalyst [Pt(colloid)/Ru(bpy)2+/MV/EDTA] yielded the following products after 25 h (µmol detected): bromide ions (250), methylene bromide (475), and unreacted bromoform (421) (Tan and Wang, 1987). Bromoform (0.11 mM) reacted with OH radicals in water (pH 8.5) at a rate of 1.3 x 108/M⋅sec

At influent concentrations of 1.0, 0.1, 0.01, and 0.001 mg/L, the adsorption capacities of the GAC used were 19.6, 5.9, 1.8, and 0.52 mg/g, respectively (Dobbs and Cohen, 1980). Exposure limits: NIOSH REL: TWA 0.5 ppm (5 mg/m3), IDLH 85e respiratory irritation (Patnaik, 1992). Toxicity: LC50 (96-h) for bluegill sunfish 29 mg/L (Spehar et al., 1982), Cyprinodon variegatus 18 ppm using natural seawater (Heitmuller et al., 1981). LC50 (72-h) for Cyprinodon variegatus 18 ppm (Heitmuller et al., 1981). LC50 (48-h) for Daphnia magna 46 mg/L (LeBlanc, 1980), Cyprinodon variegatus 19 ppm (Heitmuller et al., 1981). LC50 (24-h) for Daphnia magna 56 mg/L (LeBlanc, 1980), Cyprinodon variegatus 19 ppm (Heitmuller et al., 1981). Acute oral LD50 for rats 1,147 mg/kg, mice 1,400 mg/kg (quoted, RTECS, 1985); for male rats 1,399, female rats 1,147 mg/kg (Chu et al., 1980); male mice 1,400 mg/kg, female mice 1,550 mg/kg (Bowman et al., 1978). Heitmuller et al. (1981) reported a NOEC of 2.9 ppm. Drinking water standard (final): MCLG: zero; MCL: 0.08 mg/L. Total for all trihalomethanes cannot exceed a concentration of 0.08 mg/L. In addition, a DWEL of 700 µg/L was recommended (U.S. EPA, 2000). Uses: Solvent for waxes, greases, and oils; separating solids with lower densities; component of fire-resistant chemicals; geological assaying; medicine (sedative); gauge fluid; intermediate in organic synthesis.