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DESIGNATIONS
CAS No.: 71-55-6
Registry name: 1,1,1-Trichloroethane
Chemical name: Ethane, 1,1,1-trichloro
Synonyms, Trade names: Methyl chloroform, Aerothene, TT, alpha-trichloroethane, Armaclean, Baltane, Champion Fluid, Chlorotene, Chlorothane NU, Chlorothene, Chlorten, Dowclene WR, Drivertan, Escothen, FO 178, Genklene, Inhibisol, K 31, Mecloran, methyltrichloromethane, NCI-CO4626, Solvethane, Telclair X 31, 1,1,1-tri, triethane, Vythene C, Wacker 3X1
Chemical name (German): 1,1,1-Trichlorethan, Methylchloroform
Chemical name (French): Trichloro-1,1,1-éthane, chlorethéne, méthylchloroforme
Appearance: colourless liquid with sweet, ethereal odour
BASIC CHEMICAL AND PHYSICAL DATA
| Empirical formula: | C2H3Cl3 |
| Rel. molecular mass: | 133.41 |
| Density: | 1.338 g/cm3 |
| Relative gas density: | 4.55 |
| Boiling point: | 74.1°C |
| Melting point: | -32.6°C |
| Vapour pressure: | 133 hPa at 20°C; 200 hPa at 30°C; 445 hPa at 50°C |
| Ignition temperature: | 537°C |
| Explosion limits: | 8.0 - 10.5 vol% |
| Odour threshold: | 100 ppm |
| Solvolysis/solubility: | in water: 1.3 g/l; readily soluble in acetone, benzene, carbon tetrachloride, methanol, diethylether, carbon disulphide |
| Conversion factors: | 1 ppm = 5.54 mg/m3 |
| 1 mg/m3 = 0.183 ppm |
ORIGIN AND USE
Usage:
According to BGA (1985) about 30% were used as solvents for hot
degreasing of metals, 30% for cold degreasing of metals, 30% as
solvents in dyes, putties, adhesives, engine cleaners, polishes,
lubricants, shrinkdown films, protective coatings, insecticides
and aerosols and 10% for miscellaneous purposes such as
typewriter corrector fluid. Nowadays, the demand has decreased
because of stringent regulations in many industrialised
countries. This solvent has been replaced by other products in
several applications. Stabilisers are always added to the
marketed product. The German Order Governing Working Media (1980)
classes 1,1,1-trichloroethane as hazardous to health.
Origin/derivation:
1,1,1-trichloroethane is not a natural product; it is produced
industrially from 1,2-dichloroethane or ethane.
Production figures:
| USA | 1980 | 314,022 t | (ATRI, 1985) |
| EC | 1978 | 123,000 t | (ATRI, 1985) |
| Japan | 1980 | 86,000 t | (ATRI, 1985) |
| D | 1978 | 35,000 t | (DVGW, 1985) |
| Worldwide | 1984 | 450,000 t | (ULLMANN, 1986) |
Toxicity
| Mammals: | ||
| Mouse: | LD50 2,568-9,700 mg/kg, oral | acc. EPA, 1984 |
| Rat: | LD50 10,000 mg/kg (14 d) | acc. UBA, 1986 |
| Rat: | LD50 11,000-14,300 mg/kg, oral | acc. EPA, 1984 |
| Rabbit: | LD50 15,800 mg/kg, dermal | acc. EPA, 1984 |
| Dog: | LD50 4,140 mg/kg, intravenous | acc. EPA, 1984 |
| Guinea pig: | LD50 8,600 mg/kg, oral | acc. EPA, 1984 |
| Aquatic organisms: | ||
| Golden orfe: | LC0 94 mg/l (48 h) | acc. UBA, 1986 |
| Golden orfe: | LC50 123 mg/l (48 h) | acc. UBA, 1986 |
| Golden orfe: | LC100 201 mg/l (48 h) | acc. UBA, 1986 |
| American minnow: | LC50 52.8-105 mg/l (96 h) | acc. UBA, 1986 |
| Blue perch: | LC50 69.7 mg/l (96 h) | acc. UBA, 1986 |
| Water flea: | LC0 2,275 mg/l (24 h) | acc. UBA, 1986 |
| Water flea: | LC50 530 mg/l (48 h) | acc. UBA, 1986 |
| Water flea: | LC100 2,384 mg/l (24 h) | acc. UBA, 1986 |
| Blue algae: | EC3 350 mg/l (7 d, pH=7) | acc. UBA, 1986 |
| Green algae: | EC3 430 mg/l (7 d, pH=7) | acc. UBA, 1986 |
| Invertebrates: | ||
| Pseudomonas putida: | EC10 > 100 mg/l (30 min) | acc. UBA, 1986 |
| Pseudomonas putida: | EC3 > 100 mg/l (16 h, pH=7) | acc. UBA, 1986 |
| Uronema parduczi: | EC5 > 1,040 mg/l (20 h, pH=6.8) | acc. UBA, 1986 |
Characteristic effects:
Humans/mammals: The inhalation of 1,1,1-trichloroethane has a narcotic effect. In contrast to the comparable solvents trichloroethylene ("Tri") and tetrachloroethylene ("Per"), this substance is considerably less toxic. Like other chlorinated hydrocarbons, 1,1,1-trichloroethane may cause severe damages of the liver.
The inhalation of large concentrations causes loss of consciousness, numbness, retarded reaction and respiratory and circulatory paralysis with lethal consequences. The threshold concentration for the occurrence of paralysis in humans is 500 ppm; narcotic effects are observed at 1000 ppm (BGA, 1985). Due to the findings of American studies, 1,1,1-trichloroethane is suspected to cause malignant liver tumours.
In the Federal Republic of Germany, 1,1,1-trichloroethane is listed under pregnancy group C (no hazard of damage to embryos given compliance with MAK and BAT values).
ENVIRONMENTAL BEHAVIOUR
Water:
1,1,1-trichloroethane is heavier than water and thus sinks even
in groundwater. It enters the biocycle via the water path. It is
ubiquitously detected in surface water; increased concentrations
have been observed in recent years in the sea.
Air:
90% of the entire production finally evaporates into the
atmosphere and thus participates in the depletion of the ozone
layer (DVGW, 1985).
Soil:
1,1,1-trichloroethane accumulates in water-unsaturated soils
and in sewage sludge.
Half-life:
The half-life in water-unsaturated soils is more than 2 years.
The tropospheric half-life is estimated at 5-10 years (UBA,
1986), with the estimated figure for seawater being 39 weeks,
given pH = 8 and 10°C (ATRI, 1985).
Degradation, decomposition products:
Degradation in the troposphere - according to ATRI (1985)
some 15% of the total amount liberated - finally results by way
of phosgene in CO2 and HCl. The reaction with ozone
depletes the ozone layer (0.4% by trichloroethane (ATRI, 1985)).
Recent investigations have revealed that 1,1,1-trichloroethane
may be converted into the toxic 1,2-dichloroethene in the
C-horizon (DVGW, 1985).
Food chain:
Roughly 79% of 1,1,1-trichloroethane is absorbed via respiration,
17% by way of foodstuffs and 4% in drinking water.
ENVIRONMENTAL STANDARDS
| Medium/ acceptor |
Sector | Country/ organ. | Status | Value | Cat. | Remarks | Source |
| Water: | Drinkw | D | L | 0.01 mg/l | 1) | acc. TVO, 1990 | |
| Drinkw | EC | G | 1 µg/l | 2) | acc. DVGW, 1985 | ||
| Groundw | D | G | 25 µg/l | 1) | acc. UBA, 1986 | ||
| Air: | D | L | 90 mg/m3 | MIK | Short-time value | acc. BAUM, 1988 | |
| D | L | 30 mg/m3 | MIK | Long-time value | acc. BAUM, 1988 | ||
| Emiss. | D | L | 0.1 g/m3 | mass flow > 2 kg/h | acc. TA Luft, 1986 | ||
| Workp | D | L | 1,080 mg/m3 | MAK | DFG, 1989 | ||
| Workp | SU | (L) | 20 mg/m3 | PDK | acc. SORBE, 1986 | ||
| Workp | USA | L | 1,900 mg/m3 | Long-time value | ACGIH, 1986 | ||
| Workp | USA | L | 2,450 mg/m3 | Short-time value | ACGIH, 1986 | ||
| Foodstuffs: | D | L | 0.1 mg/kg | 3) | acc. UMWELT, 1989 | ||
| D | L | 0.2 mg/kg | 4) | acc. UMWELT, 1989 |
Notes:
1) Total concentration for 1,1,1-trichloroethane, dichloromethane, trichloroethylene and tetrachloroethylene
2) Sum total of org. chlorine compounds except pesticides
3) 0.1 mg/kg for one of the following substances in each case: tetrachloroethylene, trichloroethane or chloroform
4) As sum total of several solvents within a foodstuff product.
Comparison/reference values
| Medium/origin | Country | Value |
Source |
| Surface water: | |||
| Rhine tributaries, 1978 | D | 0.1-20 µg/l |
acc. DVGW, 1985 |
| Rhine: (Lobith, 1978) | D | 0.01-0.67 µg/l |
acc. DVGW, 1985 |
| Main: (Kostheim, 1978) | D | 1.76-2.57 µg/l |
acc. DVGW, 1985 |
| Lower Main (1980) | D | max. 98 µg/l |
acc. DVGW, 1985 |
| Drinking water: | |||
| Ried (1980) | D | max. 1.5 µg/l |
acc. DVGW, 1985 |
| Mannheim (1980) | D | max. 2.5 µg/l |
acc. DVGW, 1985 |
| Japan (5 cities, 1977) | J | max. 0.5 µg/l |
acc. DVGW, 1985 |
| Vienna (1980) | A | 0.11 µg/l |
acc. DVGW, 1985 |
| Gothenburg (1978) | S | 0.06 µg/l |
acc. DVGW, 1985 |
| Air: | |||
| Mean air concentration | 0.1 µg/m3 |
acc. DVGW, 1985 | |
| Densely populated areas | 0.5-1 µg/m3 |
acc. DVGW, 1985 | |
| Bremen (May-June 1980) | D | 0.98 µg/m3 (n=15) |
acc. ATRI, 1985 |
| Bochum (June-Dec. 1978) | D | 1.8 µg/m3 |
acc. ATRI, 1985 |
| Niagara Falls and Buffalo | USA | 3,600 ng/m3 |
acc. ATRI, 1985 |
| Sediment: | |||
| Ruhr (1972-1981) | D | < 1 µg/l |
acc. DVGW, 1985 |
| Sewage sludge | GB | 0.02 mg/kg |
acc. ATRI, 1985 |
| Foodstuffs: | |||
| Dairy products and fruit | D | max. 0.6 µg/kg |
acc. ATRI, 1985 |
| Olive oil | E | 10 µg/kg |
acc. ATRI, 1985 |
| Beef, fat | GB | 6 µg/kg |
acc. ATRI, 1985 |
| Potatoes | GB | 4 µg/kg |
acc. ATRI, 1985 |
Assessment/comments
Although 1,1,1-trichloroethane is less toxic than other chlorinated hydrocarbons, the substance cannot be used without restriction. Chronic exposure to low concentrations can cause malignant liver tumours. However, another difference between 1,1,1-trichloroethane and tri- or tetrachloroethylene is its higher stabiliser content which in turn may be harmful. Thus, a substance which is only slightly toxic in its pure form may be highly toxic because of its additives. Residues increasingly accumulate in groundwater as well as in the atmosphere.