SPECTRUM

Chemical Fact Sheet

Chemical Abstract Number (CAS #) 95501
CASRN 95-50-1
Synonyms1,2-Dichlorobenzene
Benzene, 1,2-dichloro-
o-Dichlorobenzene
Analytical Methods EPA Method 502.2
EPA Method 503.1
EPA Method 524.2
EPA Method 601
EPA Method 602
EPA Method 612
EPA Method 624
EPA Method 625
EPA Method 8010
EPA Method 8021
EPA Method 8120
EPA Method 8270
EPA Method 8260
Molecular FormulaC6H4Cl2

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

Use SOLVENT FOR WAXES, GUMS, RESINS, TARS, RUBBERS, OILS, ASPHALTS, INSECTICIDE FOR TERMITES & LOCUST BORERS REMOVING SULFUR FROM ILLUMINATING GAS; AS INTERMED IN MFR OF DYES; AS HEAT TRANSFER MEDIUM AS DEGREASING AGENT FOR METALS, LEATHER, WOOL; AS INGREDIENT OF METAL POLISHES INDUST ODOR CONTROL Herbicide, insecticide, and soil fumigant AS SOLVENT MIXT USED TO REMOVE LEAD & CARBONACEOUS DEPOSITS FROM ENGINE PARTS; AS COMPONENT OF RUST-PROOFING MIXT AS A MAGNETIC COIL COOLANT; IN WOOD-PRESERVING CMPD CHEM INTERMED FOR MAKING AGRIC CHEM; EMULSIFIABLE FORM RECOMMENDED FOR DEODORIZING GARBAGE & SEWAGE ORG SYNTH ESP OF PESTICIDES & SOLVENT IN CHEM PROCESSES Used as a process solvent in the manufacture of toluene diisocyanate. Ortho-dichlorobenzene is used as a solvent in the following applications: motor-oil additive formulations; paints; formulations for removing paints; firearm cleaners; dissolution of pitch on papermaking felts; a carrier for wood preservatives and repellents; and upper cylinder lubricants Hydrolysis of 1,2-dichlorobenzene with KOH and NaOH gives ortho-chlorophenol an intermediate for dyestuffs and initiator for higher chlorinated phenols Manufacture of 3,4-dichloroaniline, solvent for oxides of non-ferrous metals
Consumption Patterns 53% FOR ORGANIC SYNTHESIS (CHIEFLY FOR PESTICIDES); 20% FOR SOLVENT IN TOLUENE DI-ISOCYANATE PROCESS; 15% FOR MISC SOLVENT USES; 8% FOR DYESTUFFS MFR, 4% FOR MISC USES (1973) Organic synthesis (mainly for production of 3,4-dichloroaniline), 70%; solvents for toluene diisocyanate production, 15%; miscellaneous solvent usage, 8%; dye manufacture 4%; and other application, 3% (1978) CHEMICAL PROFILE: o-Dichlorobenzene. Organic synthesis (mainly for 3,-dichloroaniline herbicides, via 3,4-dichloronitrobenzene), 90%; toluene diisocyanate processing solvent, 5%; solvent and miscellaneous uses, 5%. CHEMICAL PROFILE: o-Dichlorobenzene. Demand: 1986: 45 million lb; 1987: 45 million lb; 1991 projected/: 43 million lb.
Apparent Color COLORLESS LIQUID
Odor PLEASANT AROMATIC ODOR
Boiling Point 180.5 DEG C @ 760 MM HG
Melting Point -17.0 DEG C
Molecular Weight 147.01
Density 1.3048 g/ml @ 20 DEG C/4 DEG C
Odor Threshold Concentration ODOR OF O-DICHLOROBENZENE IS DETECTABLE BY AVG PERSON AT 50 PPM IN AIR. ODOR BECOMES STRONG & IRRITATION NOTICEABLE AT CONCN AROUND 100 PPM. IT HAS FAIR WARNING PROPERTIES AT THIS LEVEL BUT POSSIBILITY OF ADAPTATION SHOULD BE RECOGNIZED. Odor threshold low= 12.0 mg/cu-m, Odor threshold high= 300.0 mg/cu-m, Irritating concentration= 150.0 mg/cu-m (From table).
Sensitivity Data Intense erythema and edema appeared promptly when the cmpd is applied locally. VAPORS AND SPRAYS ARE IRRITATING TO EYES, NOSE AND THROAT
Environmental Impact Chemical waste dump leachates and direct manufacturing effluents are reported to be the major source of pollution of the chlorobenzenes (including the dichlorobenzenes) to Lake Ontario. The major source of 1,2-dichlorobenzene emission to the atmosphere has been reported to be solvent applications which may emit 25% of annual production to the atmosphere. If released to soil, 1,2-dichlorobenzene can be moderately to tightly adsorbed. Leaching from hazardous waste disposal areas has occurred and the detection of 1,2-dichlorobenzene in various groundwaters indicates that leaching can occur. Volatilization from soil surfaces may be an important transport mechanism. It is possible that 1,2-dichlorobenzene will be slowly biodegraded in soil under aerobic conditions. Chemical transformation by hydrolysis, oxidation or direct photolysis are not expected to occur in soil. If released to water, adsorption to sediment will be a major environmental fate process based upon extensive monitoring data in the Great Lakes area and Koc values. Analysis of Lake Ontario sediment cores has indicated the presence and persistence of 1,2-dichlorobenzene since before 1940. 1,2-Dichlorobenzene is volatile from the water column with an estimated half-life of 4.4 hours from a model river one meter deep flowing 1 m/sec with a wind velocity of 3 m/sec at 20 deg C; adsorption to sediment will attenuate volatilization. Aerobic biodegradation in water may be possible, however, anaerobic biodegradation is not expected to occur. Experimental BCF values of 66-560 have been reported and 1,2-dichlorobenzene has been detected in trout from Lake Ontario. Aquatic hydrolysis, oxidation and direct photolysis are not expected to be important. If released to air, 1,2-dichlorobenzene will exist predominantly in the vapor-phase and will react with photochemically produced hydroxyl radicals at an estimated half-life rate of 24 days in a typical atmosphere. Direct photolysis in the troposphere is not expected to be important. The detection of 1,2-dichlorobenzene in rainwater suggests that atmospheric removal via wash-out is possible. General population exposure to 1,2-dichlorobenzene may occur through oral consumption of contaminated drinking water and food (particularly fish) and through inhalation of contaminated air since 1,2-dichlorobenzene has been detected in widespread ambient air.
Environmental Fate Aquatic fate: Since 1,2-dichlorobenzene (1,2-DCB) has a high affinity for lipophilic materials and is reported to have a relatively low vapor pressure and low aqueous solubility at ambient temperatures, sorption, bioaccumulation, and volatilization are expected to be competing proceses. The rate at which each of these competing processes occur will determine which fate is predominant for 1,2-DCB in the aquatic environment. Should volatilization occur at a more rapid rate then sorption or bioaccumulation then atmospheric proceses would be expected to regulate the fate of 1,2-DCB. On the other hand should sorption and bioaccumulation occur more rapidly than volatilization, biodegradation of 1,2-DCB by aquatic microorganisms would be anticipated to regulate the fate of this compound. TERRESTRIAL FATE: Based on experimental adsorption data, 1,2-dichlorobenzene can be moderately to tightly adsorbed in soil. Leaching from hazardous waste disposal areas in Niagara Falls to adjacent surface waters has been reported and the detection of 1,2-dichlorobenzene in various groundwaters indicates that leaching can occur. Volatilization from soil surfaces may be an important transport mechanism; however, volatilization may be attenuated by tight adsorption to soil particles or by leaching. It is possible that 1,2-dichlorobenzene will be slowly biodegraded in soil under aerobic conditions. Chemical transformation processes such as hydrolysis, oxidation or direct photolysis (on soil surfaces) are not expected to occur. AQUATIC FATE: Based on suspended solid monitored Koc values of about 39800 and extensive sediment monitoring data in the Great Lakes area, adsorption to sediment is a major environmental fate process for 1,2-dichlorobenzene. Its detection in Lake Ontario sediment cores indicates that 1,2-dichlorobenzene has persisted in these sediments since before 1940 . 1,2-Dichlorobenzene is volatile from water with an estimated half-life of 4.4 hours from a river one meter deep flowing 1 m/sec with a wind velocity of 3 m/sec at 20 deg C; adsorption to sediment in water will attenuate volatilization 1,2-Dichlorobenzene may biodegrade in aerobic water after microbial adaptation; however, it is not expected to biodegrade under anaerobic conditions which may exist in lake sediments or various groundwaters. Experimental BCF values of 66-560 have been reported; the detection of 1,2-dichlorobenzene in trout from Lake Ontario has confirmed that bioaccumulation is important. Aquatic hydrolysis, oxidation and direct photolysis are not expected to be important. The persistence half-life of 1,2-dichlorobenzene in the water column has been estimated to be 0.3-3 days in rivers, 3-30 days in lakes and 30-300 days in groundwaters(2,SRC). ATMOSPHERIC FATE: 1,2-Dichlorobenzene will exist predominantly in the vapor- phase in the atmosphere. The half-life for the vapor-phase reaction of 1,2-dichlorobenzene with photochemically produced hydroxyl radicals in the atmosphere has been estimated to be 24 days. Direct photolysis is not expected to be important. The detection of 1,2-dichlorobenzene in rainwater suggests that atmospheric removal via wash-out is possible.
Drinking Water Impact DRINKING WATER: A mean 1,2-dichlorobenzene concn of 0.003 ppb was detected in drinking water samples from 3 cities near Lake Ontario in 1980 . Concn of 1 ppb identified in Miami, FL drinking water and qualitative detections reported for Philadelphia, PA and Cincinnati, OH . 1,2-Dichlorobenzene was found in 2 of 945 finished water supplies throughout the US that use groundwater sources at concn of 2.2 and 2.7 ppb . Qualitative detection reported for Cleveland, OH tap water . Qualitative detection reported for two drinking water supply sources in the United Kingdom . GROUNDWATER: 1,2-Dichlorobenzene was positively detected in 20 of 685 groundwaters analyzed in NJ during 1977-1979 with 6800 ppb the highest concn found . SURFACE WATERS: 1,2-Dichlorobenzene was detected in 15 of 463 surface waters analyzed in NJ during 1977-1979 with 8.2 ppb the highest concn found . Mean concentrations of 5 and 6 parts per trillion detected in Lake Ontario and Grand River water, respectively, during 1980 near Niagara Falls; concn of 0-56 parts per trillion found in the Niagara River . Concn of 3.9-240 parts per trillion (mean concn of 23 parts per trillion) detected in Niagara River at Niagara-On-The-Lake between 1981 and 1983 . Concn of 5.6-190 parts per trillion (mean concn of 18 parts per trillion) detected in the Niagara River between 1981 and 1983 . An average concn of 20 parts per trillion was found in the Niagara River near Niagara-On-The-Lake between Sept and Oct 1982 . Positive detection of 1,2-dichlorobenzene was reported by 0.6% of 1077 USEPA STORET stations(6). Qualitative detection reported for the Delaware and Raritan Canal in NJ(7). Concn below 0.5 ppb detected in the Rhine River between 1978-1982(8). An average concn of 0.32 ppb found in the Rhine River near Dusseldorf in 1984(9). SEA WATER: 1,2-Dichlorobenzene was detected in the water column of the Narragansett Bay near Rhode Island . RAIN/SNOW: A mean 1,2-dichlorobenzene concn of 0.49 parts per trillion was detected in Portland, OR rainwater during March-April 1982 ; Concn of not detected to 0.62 parts per trillion found in Portland, OR rainwater during 1984 . EFFL: The wastewater effluents from four water treatment plants discharging into the Grand River and Lake Ontario contained a mean 1,2-dichlorobenzene concn of 13 ppt during 1980 sampling . Positive detection of 1,2-dichlorobenzene was reported by 2.5% of 1311 USEPA STORET stations . Concn of 0.3-41 ppb were detected in Southern California municipal wastewater effluents in 1976 . Concn of 10-32 ppb were detected in leachates from municipal solid waste landfills in Minnesota . Concn of 2.8-13 ppb found in leachate associated groundwater beneath a municipal landfill in Ontario, Canada . The dichlorobenzene isomers were qualitatively detected in waters adjacent to hazardous waste disposal areas in Niagara Falls, NY as a result of leaching(6). Ambient mean air concn of 0.04-0.86 ppb were detected above six abandoned hazardous waste sites in NJ as a result of volatile emanations(7). Flue gas effluents from a municipal refuse-fired steam boiler in Virginia contained 4.4 ug/cu m of the dichlorobenzene isomers(8); flue gas effluents from a refuse-derived-fired power plant in Ohio contained 7.8 ng/cu m of the dichlorobenzene isomers(8).

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