|Chemical Abstract Number (CAS #)||
|Synonyms||Chlorobenzene||Benzene, chloro-||Benzene chloride||Monochlorobenzene
||EPA Method 502.2||EPA Method 503.1
||EPA Method 524.2
||EPA Method 601
||EPA Method 602
||EPA Method 624
||EPA Method 8010
||EPA Method 8021
||EPA Method 8260
Link to the National Library of Medicine's Hazardous Substances
Database for more details
on this compound.
|Use|| SOLVENT FOR PAINTS
SOMETIMES USED IN DRY-CLEANING
CHEM INT FOR PHENOL, O- & P-CHLORONITROBENZENE, DDT, & ANILINE
USED IN MFR OF INSECTICIDES & AS INT IN MFR OF DYESTUFFS
SOLVENT CARRIER FOR METHYLENE DIISOCYANATE
Used as a fiber swelling agent and dye carrier in textile processing, a tar and grease remover in
cleaning and degreasing operations, a solvent in surface coating and surface coating removers.
Used as a solvent in the manufacture of adhesives, paints, polishes, waxes, diisocyanates,
pharmaceuticals, and natural rubber.
|Consumption Patterns|| 32% FOR O- AND P-CHLORONITROBENZENES; 27% FOR PHENOL; 5% FOR
DDT; 36% FOR MISC APPLICATIONS INCLUDING SYNTHESIS OF ANILINE AND USE
AS A SOLVENT (1972)
Solvent (pesticide formulation, TDI processing, degreasing agent), 42%; Nitrochlorobenzenes,
32%; Diphenyl oxide and phenylphenols, 15%; Miscellaneous, 11% (1985)
CHEMICAL PROFILE: Monochlorobenzene. Nitrochlorobenzenes, 40%; solvent (for pesticide
formulations, TDI processing and degreasing), 27%; diphenyl oxide and phenylphenols, 20%;
polysulfone polymers, 5%; miscellaneous, 8%.
CHEMICAL PROFILE: Monochlorobenzene. Demand: 1986: 222 million lb; 1987: 220 million
lb; 1991 projected/: 195 million lb.
|Apparent Color|| COLORLESS LIQUID
|Odor|| FAINT, NOT UNPLEASANT ODOR ; ALMOND-LIKE ODOR ; Mild amine odor ;
|Boiling Point|| 132 DEG C
|Melting Point|| -45.6 DEG C
|Molecular Weight|| 112.56
|Density|| 1.1058 @ 20 DEG C/4 DEG C
|Odor Threshold Concentration|| Odor recognition in air: 2.10x10-1 ppm.
Odor Low, 0.98 mg/cu m; Odor High, 280.0 mg/cu m
|Sensitivity Data|| If spilled on clothing and allowed to remain, may cause smarting and reddening of the skin.
Irritation of the eyes and nose.
|Environmental Impact|| Chlorobenzene will enter the atmosphere from fugitive emissions connected with its use
as a solvent in pesticide formulations and as an industrial solvent. Once released it will decrease in
concentration due to dilution and photooxidation. Releases into water and onto land will decrease
in concentration due to vaporization into the atmosphere and slow biodegradation in the soil or
water. Chlorobenzene would be expected to percolate into the ground water if soil is sandy and
poor in organic matter. Little bioconcentration is expected into fish and food products. Primary
human exposure is from ambient air, especially near point sources.
|Environmental Fate|| TERRESTRIAL FATE: Since chlorobenzene is fairly volatile, much of it will be lost to
the atmosphere . It is relatively mobile in sandy soil and aquifer material and biodegrades very
slowly or not at all in these soils(2-5). Therefore, it can be expected to leach into the
groundwater. It has a moderate adsorption onto organic soil and if retained long enough it
will biodegrade and even mineralize in soil(6). Degradation will generally be slow, but fairly rapid
mineralization (20%/week) has been reported in one study(7). Acclimation of soil microorganisms
is an important factor(8).
AQUATIC FATE: The primary loss will be due to evaporation. The rate of evaporation will
depend on the wind speed and water movement. The half-life for evaporation is approximately 4.5
hours with moderate wind speed . Biodegradation will occur during the warmer seasons and
will proceed more rapidly in fresh water than in estuarine and marine systems(2,3). The rate will
also depend on the acclimation of microbial communities to chlorobenzene or related chemicals.
One reported half-life for an estuarine river with near natural conditions (22 deg C) is 75 days .
A moderate amount of adsorption will occur onto organic sediments .
ATMOSPHERIC FATE: Reaction with hydroxyl radicals is the dominant removal mechanism
with an estimated half-life of 9 days with the formation of chlorophenols . Reaction in polluted
air with nitric oxide is somewhat faster and produces chloronitrobenzene and
chloronitrophenols . Photolysis would proceed at a much slower rate, with monochlorobiphenyl
being produced .
|Drinking Water Impact|| DRINKING WATER: 1975 USEPA National Organics Reconnaissance Survey (NORS)
finished drinking water samples: Miami, FL - 1 ug/L; Seattle, WA - not detected (detection limit
not reported); Cincinnati, OH - 0.1 ug/L; Ottumwa, IA - not detected; and Philadelphia, PA -
<0.1 ug/L . Finished water in 9 of 10 supplies surveyed by the USEPA contained chlorobenzene
with 5.6 and 4.7 ppb in Terrebonne Parish, LA and New York City, respectively(7).
Chlorobenzene may be formed during chlorination(7). GROUNDWATER: As of June 30, 1984 -
Wisconsin, 1174 community wells, 0% pos; 617 private wells, 0% pos, detection limit 1.0-5.0
ug/L . During 1981-1982, 945 wells scattered throughout the USA, 0.1% pos., concn detected
2.7 ug/L, detection limit 0.5 ug/L(8). 14 ppt (Zurich, 1973) under densely populated, partly
industrial area . SURFACE WATER: Ohio River Basin (large survey, 1980-1981) detected in
9.6% of samples, but only 0.01% were >1 ppb. Maximum concentration was >10 ppb . In 14
Industrial River Basins (1975-76), only 5% of samples in the range 1-4 ppb . SEAWATER:
Not detected in Raritan Bay (Lower Hudson)(6).
Monochlorobenzenes were detected in groundwater in Miami, FL at a concn of 1.0 mg/l.
Monochlorobenzenes were detected in raw water contaminated with municipal waste in
Philadelphia, PA at concn of 0.1 mg/l.
Monochlorobenzenes were detected in raw water contaminated with industrial discharge in
Cincinnati, OH and Lawrence, MA at concn of 0.1-0.5 mg/l and 0.12 mg/l, respectively.
EFFL: Monochlorobenzenes were detected in industrial discharge in Lawsons Fork Creek, SC at
a concn of 8.0-17.0 mg/l.
Monochlorobenzenes were detected in the municipal water in Coosa River, GA at a concn of 27.0
The concentrations of volatile organic chemicals in the air of three wastewater treatment plants,
were compared on the basis of samplings carried out with charcoal tubes during a period of 7
consecutive days. Combustible organic vapor content was determined with an organic vapor
analyzer provided with a flame ionization detector. The highest organic vapor concentrations (300
ppm) in the air were recorded at the plant that was processing the highest proportion of industrial
wastewater; at this plant, the air levels of methyl-isobutyl-ketone, chlorobenzene, toluene, and
benzene were correlated significantly with the concentration of total organic vapors in the air.
Significant correlations between waste water and air space were established only for the
concentrations of trichloroethylene, 1,1,1-trichloroethane and perchloroethylene; no such
correlations were encountered for the concentrations of total aliphatic and nonaliphatic
hydrocarbons or for total specific compounds. Comparison between the time weighted averages
of 24 organics in the air obtained with the charcoal tubes and analyzed by gas chromatography
and those obtained with the flame ionization detector and organic vapor analyzer system revealed
that the total organics calculated according to the former method amounted to less than 10
percent of the time weighted average results from the flame ionization detector and organic vapor