|Chemical Abstract Number (CAS #)||
|Synonyms||1,1,1-Trichloroethane||Ethane, 1,1,1-trichloro-||Methyl chloroform
||EPA Method 502.2||EPA Method 524.2
||EPA Method 601
||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 NATURAL & SYNTHETIC RESINS, OILS, WAXES, TAR &
DRY CLEANING AGENT
IN COLD TYPE METAL CLEANING, CLEANING PLASTIC MOLDS
FORMERLY USED WITH ETHYLENE GAS FOR DEGREENING CITRUS FRUITS &
POSTHARVEST FUMIGATION OF STRAWBERRIES
Solvent for various insecticides Former use
SPOTTING FLUID IN TEXTILE PROCESSING; CHEM INT FOR ORG CHEMS (EG,
VINYLIDENE CHLORIDE); SOLVENT FOR ADHESIVES & COATINGS; COOLANT &
LUBRICANT IN METAL CUTTING OILS; EXTRACTION SOLVENT; COMPONENT OF
INKS & DRAIN CLEANERS; SOLVENT FOR PHOTORESIST POLYMERS; SOLVENT IN
In aerosols, in which it acts both as a vapor pressure depressant and as a solvent and carrier for
many of the active ingredients used in aerosols.
Solvent for cleaning precision instruments; metal degreasing, pesticide, textile processing.
|Consumption Patterns|| Cold cleaning, 40%; Vapor degreasing, 22%; Adhesives, 12%; Aerosols, 10%; Exports,
5%; Electronics, 6%; Coatings, 1%; Miscellaneous, 4%.
CLEANING SOLVENT, 70%; AEROSOLS, 5%; CHEM INT, 3%; OTHER, 22% (1980, EST)
Cold cleaning, 41%; vapor degreasing, 22%; adhesives, 10%; aerosols, 7%; electronics, 6%;
intermediate, 4%; coatings, 2%; other, 1%; export, 7% (1985).
CHEMICAL PROFILE: 1,1,-Trichloroethane. Vapor degreasing, 34%; cold cleaning, 12%;
aerosols, 10%; adhesives, 8%; intermediate, 7%; coatings, 5%; electronics, 4%; other, 5%;
CHEMICAL PROFILE: 1,1,1-Trichloroethane. Demand: 1988: 700 million lb; 1989: 705 million
lb; 1993 projected/: 735 million lb. (Includes exports as well as imports, which totaled about 40
million lb last year.)
|Apparent Color|| COLORLESS LIQUID
|Odor|| CHLOROFORM-LIKE ODOR; SWEETISH
|Boiling Point|| 74.1 DEG C AT 760 MM HG
|Melting Point|| -30.4 DEG C
|Molecular Weight|| 133.42
|Density|| 1.3376 AT 20 DEG C/4 DEG C
|Odor Threshold Concentration|| 44 ppm
|Sensitivity Data|| Vapors cause a slight smarting of the eyes or respiratory system if present in high concn.
Vapors: Irritating to nose and throat. Liquid: irritating to eyes.
If the liquid is spilled on clothing and allowed to remain, may cause smarting and reddening of the
|Environmental Impact|| 1,1,1-Trichloroethane is likely to enter the environment from air emissions or in
wastewater from its production or use in vapor degreasing, metal cleaning, etc. It can also enter
the environment in leachates and volatile emissions from landfills. Releases to surface water will
decrease in concn almost entirely due to evaporation. Spills on land will decrease in concentration
almost entirely due to volatilization and leaching. Releases to air may be transported long
distances and partially return to earth in rain. In the troposphere, 1,1,1-trichloroethane will
degrade very slowly by photooxidation and also slowly diffuse to the stratosphere where
photodegradation will be rapid. Major human exposure is from air and drinking water. Exposure
can be high near sources of emission or where drinking water is contaminated.
|Environmental Fate|| TERRESTRIAL FATE: 1,1,1-Trichloroethane evaporates fairly rapidly into the
atmosphere because of its high vapor pressure. Because 1,1,1-trichloroethane does not adsorb
strongly to soil, it should leach extensively.
AQUATIC FATE: Primary loss will be by evaporation into the atmosphere. Half-life will range
from hours to a few weeks depending on wind and mixing conditions. Half-lives in a mesocosm
simulating the conditions in Narragansett Bay were 24, 12, and 11 days under spring, summer and
winter conditions, respectively . Biodegradation and adsorption onto particulate matter will be
insignificant relative to volatilization . Turbulance in microcosm tanks are substantially less
than in the bay or the open ocean so volatilization may be significantly (up to an order of
magnitude) faster in the bay or open water than measured in the mesocosms.
ATMOSPHERIC FATE: 1,1,1-trichloroethane is fairly stable in the atmosphere and is
transported long distances, being found even at the South Pole (1,2,3). It is transported to
Barrows, Alaska from the mid-latitudes . It is slowly degraded principally by reaction with
hydroxyl radicals and has a half-life of 6 months to 25 years (2,4). The global lifetime average has
been estimated to be 6.0-6.9 years(7). The rate of degradation is increased by the presence of
chlorine radicals and nitrogen oxides. 15% of the 1,1,1-trichloroethane drifts into the stratosphere
where it is rapidly degraded by photodissociation (2,4). Due to the large input of
1,1,1-trichloroethane into the atmosphere and its slow degradation, the amount of
1,1,1-trichloroethane in the atmosphere is increasing by 4.8-17% a year (6,4,7). Some of the
1,1,1-trichloroethane returns to earth in rain as is evidenced by its presence in rainwater and a
40% reduction in air concentrations on rainy days .
|Drinking Water Impact|| DRINKING WATER - 133 United States cities with finished surface water - 0.4 ppb
median, 3.3 ppb max; 23 United States cities with finished groundwater - 2.1 ppb median, 3.0
max, 22% of the samples were positive . Contaminated drinking water wells in New York, New
Jersey, Connecticut and Maine have values of 950-5440 ppb . Results of the 1982 EPA Ground
Water Supply Survey for 1,1,1-trichloroethane (466 samples) - 5.8% pos, 0.8 ppb median of
positives, 18 ppb max . As part of EPA's Total Exposure Assessment Methodology (TEAM)
study, the concentration of various toxic substances in drinking water of sample populations was
measured . The mean (maximum) concentrations of 1,1,1-trichloroethane in Bayonne and
Elizabeth, New Jersey, an industrial/chemical manufacturing area, was 0.6 (5.3), 0.2 (2.6), and 0.2
(1.6) ppb in the fall 1981, summer 1982, and winter 1983, respectively . For comparison the
drinking water of a sample of residents of a manufacturing city without a chemical or petroleum
refining industry, Greensboro, NC and a small, rural, and agricultural town in North Dakota
contained 0.03 (0.05) and 0.04 (0.07) ppb of 1,1,1-trichloroethane, respectively .
GROUNDWATER - Raw groundwater in 13 United States cities - 1.1 ppb median, 13 ppb max,
23% were positive . 1,1,1-Trichloroethane has been detected in 18.9% of all groundwater
samples analyzed from 178 sites designated as CERCLA (Comprehensive Emergency Response,
Compensation and Liability Act) sites by the USEPA monitoring program .
SURFACE WATER - Raw surface water in 105 United States cities - 0.2 ppb median, 1.2 ppb
max, 12% positive . Large study of the Ohio R. Basin in 1980-1981 (4972 samples) reports