SPECTRUM

Chemical Fact Sheet

Chemical Abstract Number (CAS #) 124481
CASRN 124-48-1
SynonymsDibromochloromethane
Chlorodibromomethane
Methane, dibromochloro-
Analytical Methods EPA Method 502.2
EPA Method 524.2
EPA Method 601
EPA Method 624
EPA Method 8010
EPA Method 8021
EPA Method 8260
Molecular FormulaCHBr2Cl

Link to the National Library of Medicine's Hazardous Substances
Database for more details on this compound.

Use LAB CHEM ORGANIC SYNTHESIS Dibromochloromethane is used as a chemical intermediate in the manufacture of fire extinguishing agents, aerosol propellants, refrigerants, and pesticides.
Apparent Color COLORLESS TO PALE YELLOW LIQUID
Boiling Point 119-120 DEG C @ 748 MM HG
Melting Point BELOW -20 DEG C (FP)
Molecular Weight 208.28
Density Specific Gravity: 2.451 @ 20 DEG C/4 DEG C
Environmental Impact The predominant anthropogenic source of chlorodibromomethane release to the environment is its inadvertent formation during chlorination treatment processes of water. In addition to anthropogenic sources, it is biosynthesized and emitted to the environment by various species of marine macroalgae which are abundant in various locations of the world's oceans. If released to surface water, volatilization will be the dominant environmental fate process. The volatilization half-life from rivers and streams has been estimated to range from 43 min to 16.6 days with a typical half-life being 46 hours. In aquatic media where volatilization is not viable (e.g. groundwater), anaerobic biodegradation may be the major removal process. Aquatic hydrolysis, oxidation, direct photolysis, adsorption, and bioconcentration are not environmentally important. If released to soil, volatilization is again likely to be the dominant removal process where exposure to air is possible. Chlorodibromomethane is moderately to highly mobile in soil and can therefore leach into groundwaters. If released to air, the only identifiable transformation process in the troposphere is reaction with hydroxyl radicals which has an estimated half-life of 8.4 months. This relatively persistent half-life indicates that long-range global transport is possible. The general population is exposed to chlorodibromomethane through consumption of contaminated drinking water, beverages, and food products, through inhalation of contaminated ambient air, and through dermal exposure to chlorinated swimming pool water.
Environmental Fate TERRESTRIAL FATE: In soils where exposure to the atmosphere can occur, volatilization is likely to be the dominant environmental fate process due to the high vapor pressure of chlorodibromomethane . Chlorodibromomethane is moderately to highly mobile in soil and can therefore leach into groundwater and subsurface regions. Laboratory studies have indicated that significant biodegradation can occur under anaerobic conditions; therefore, in soil regions where volatilization is not viable, biodegradation may be the major removal process. AQUATIC FATE: Volatilization of chlorodibromomethane is the dominant removal mechanism from environmental surface waters. The volatilization half-life from rivers and streams has been estimated to range from 43 min to 16.6 days with a typical half-life being 46 hours . Laboratory studies have indicated that significant biodegradation can occur under anaerobic conditions; therefore, in aquatic regions where volatilization is not viable, biodegradation may be the major removal process. Aquatic hydrolysis, oxidation, direct photolysis, adsorption, and bioconcentration are not environmentally important. ATMOSPHERIC FATE: Due to its high vapor pressure, chlorodibromomethane should exist entirely in the vapor-phase in the ambient atmosphere. The only identifiable transformation process in the troposphere is reaction with hydroxyl radicals which has an estimated half-life of 8.4 months in typical air . Direct photolysis does not occur below the ozone layer. This relatively persistent tropospheric half-life suggests that a small percentage of the chlorodibromomethane present in air may eventually diffuse to the stratosphere where it will be destroyed by photolysis. In addition, long-range global transport is possible. The detection of chlorodibromomethane in rainwater indicates that atmospheric removal via washout can occur; however, any chlorodibromomethane which is removed by rainfall is likely to revolatilize into the atmosphere.
Drinking Water Impact DRINKING WATER: In NW England tap water (1974): < 0.01 to 3 ppb DRINKING WATER: Detected in finished drinking water, in drinking water supplies, and in wastewater effluents. DRINKING WATER: 100 UG/L WAS HIGHEST CONCN FOUND IN FINISHED DRINKING WATER & 1.4 UG/L WAS HIGHEST CONCN FOUND IN RAW DRINKING WATER WITH NO AVAIL INFORMATION ON CHRONIC TOXICITY. FROM TABLE/ DRINKING WATER: As part of the USEPA Groundwater Supply Survey, chlorodibromomethane was positively detected in 405 of 945 USA finished water supplies that use groundwater sources at a median level of about 3.3 ppb . Median levels of 7.5-17 ppb were detected in the water supplies of over 40% of the 113 USA cities monitored during the three phases (1976-7) of USEPA National Organic Monitoring Survey . A Canadian national survey of 70 drinking water supplies found chlorodibromomethane levels of 0-33 ppb with an overall median level of 1.4 ppb . In a survey of drinking waters from 12 areas of the world (China, Taiwan, north and south Philippines, Egypt, Indonesia, Australia, England, Brazil, Nicaragua, Venezuela, Peru), chlorodibromomethane was found in 7 of the 12 waters at levels ranging from 1.1-13 ppb . Positive detections were made in 30 of 40 Michigan drinking water supplies at a median concn of 2.2 ppb . Drinking water samples collected from Los Angeles and Contra Coast, CA in 1984 contained mean concns of 8-28 ug/L . GROUNDWATER: Chlorodibromomethane was one of 27 organic compounds identified in groundwater collected from 315 wells in the area of the Potomac-Raritan-Magothy aquifer system adjacent to the Delaware River . Levels of 0.3 ppb have been detected in groundwater from the Netherlands . SURFACE WATER: An analysis of the USEPA STORET Data Base found that chlorodibromomethane had been positively detected in 8.0% of 8515 water observation stations at a median concn below 0.1 ug/l . Chlorodibromomethane was positively detected in 9.8% of 4972 samples collected from 11 stations on the Ohio River during 1980-1 with most concn between 0.1-1.0 ppb . Concentrations ranging from a trace-15 ng/l and not detected-630 ng/l were reported for 16 stations on the Niagara River and 95 stations on Lake Ontario, respectively, for 1981 monitoring . SEAWATER: Chlorodibromomethane concentrations of 0.1-2.2 ng/l have been detected in the North Atlantic while a concn of 0.12 ng/l was detected in the South Atlantic during 1985 monitoring . Qualitative detection has been reported for the Narragansett Bay off RI in 1979-80 . RAIN/SNOW: A concn of 0.4 ng/l was detected in rain collected in southern Germany in 1985 . OTHER WATER: A chlorodibromomethane concn of 2 ppb was detected in stormwater runoff from Eugene, OR as part of the USEPA Nationwide Urban Runoff Program . Chlorodibromomethane has been detected in swimming pool water at levels of 6-10 ppb . EFFL: An analysis of the USEPA STORET Data Base found that chlorodibromomethane had been positively detected in 6.5% of 1298 effluent observation stations at a median concn below 2.4 ug/l . Chlorodibromomethane was detected in 8 of 63 industrial wastewater discharges in the USA at levels ranging from <10-100 ppb . Three municipal wastewater treatment facilities in Cincinnati, OH were found to be discharging levels as high as 25 ppb in 1982 . Not detected in septic tank effluent in a Regina Saskatachewan study (detection limit not specified) .

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