1,1,2-Trichloroethylene

Trichloroethylene [79-01-6J, trichloroethene, CHCL=CCL2, commonly called tri, is a colorless, sweet smelling (chloroformlike odor), volatile Hquid and a powerhil solvent for a large number of natural and synthetic substances. It is nonflammable under conditions of recommended use. In the absence of stabilizers, it is slowly decomposed (autoxidized) by air. The oxidation products are acidic and corrosive. Stabilizers are added to all commercial grades. Trichloroethylene is moderately toxic and has narcotic properties. 

The demand for trichloroethylene grew steadily until 1970. Since that time trichloroethylene has been a less desirable solvent because of restrictions on emissions under air pollution legislation and the passage of the Occupational Safety and Health Act. Whereas previously the principal use of trichloroethylene was for vapor degreasing, currentiy 1,1,1-trichloroethane is the most used solvent for vapor degreasing. The restrictions on production of 1,1,1-trichloroethane [71-55-6] from the 1990 Amendments to the Montreal Protocol on substances that deplete the stratospheric ozone and the U.S. 

Clean Air Act 1990 Amendments will lead to a phase out of 1,1,1-trichloroethane by the year 2005, which in turn will likely result in a slight resurgence of trichloroethylene in vapor-degreasing appHcations. The total production, however, will probably stay relatively low because regulations will require equipment designed to assure minimum emissions. 

Kirk-Othmer Encyclopedia of Chemical Technology (4th Edition) 

The most important reactions of trichloroethylene are atmospheric oxidation and degradation by aluminum chloride. Atmospheric oxidation is cataly2ed by free radicals and accelerated with heat and with light, especially ultraviolet. The addition of oxygen leads to intermediates (1) and (2). 

Trichloroethylene is a solvent with an odor threshold of 0.5 mg L-1. It is classified by the EPA as a probable human carcinogen (Group B2). 

Typical Boiling Point Curve of Trichloroethylene-MicMral Oil Mixture 

Bardodej Z, Vyskocil J The problem of trichloroethylene in occupational medicine. AMA Archives of Industrial Hygiene and Occupational Medicine 13 581-592, 1956 

Bernad PG, Spyker NS Neurotoxicity and behavior abnormalities in a cohort chronically exposed to trichloroethylene (abstract). Vet Hum Toxicol 29 475, 1987 Eichert H Trichloroethylene intoxication. JAMA 106 1652-1654, 1936 Feldman RG, Mayer RM, Taub A Evidence for peripheral neurotoxic effect of trichloroethylene. Neurology 20 599-606, 1970 

Feldman RG, White RF, Currie JN, et al Long-term follow-up after single toxic exposure to trichloroethylene. Am J Ind Med 8 119-126, 1985 Grandjean E, Munchinger R, Turrian V, et al Investigations into the effects of exposure to trichloroethylene in mechanical engineering. British Journal of Industrial Medicine 12 131-142, 1955 

Harenko A Two peculiar instances of psychotic disturbance in trichloroethylene poisoning. Acta Neurol Scand Suppl 31 139-140, 1967 Landrigan PJ, Stein GF, Kominsky JR, et al Common-source community and industrial exposure to trichloroethylene. Arch Environ Health 42 327-332, 1987 Lilis R, Stanescu D, Muica N, et al Chronic effects of trichloroethylene exposure. Med Lav 60 595-601, 1969 

McCunney RJ Diverse manifestations of trichloroethylene. British Journal of Industrial Medicine 45 122-126, 1988 

The assessment of liver cancer risks associated with human exposure to trichloroethylene (TCE) was initially conducted by Fisher and Allen (1993) using a PBPK-modeling approach. The use of the amount of TCE metabolized per day as dose metric used in the linearized multistage model led to lOppb in air and 7 ag/L in water as acceptable concentrations—that is, environmental levels corresponding to a population cancer risk of 1 in 10 (Fisher and Allen 1993). Corresponding values based on circulating levels of the metabolite, trichloroacetic acid, were 10 times and twice lower than those based on the amount of TCE metabolized per unit time, whereas the acceptable TCE concentration in air as defined by the EPA at the time was 90 times lower. A number of authors subsequently investigated the dose metrics and cancer risks associated with TCE [e.g., Bois (2000), CleweU and Andersen 

Hydrated lime is used as an alkaline catalyst to promote the self-condensation of acetone to form diacetone alcohol (4-hydroxy-4-methyl-2-pentanone) [31.26]. Diacetone alcohol is used as a solvent for natural and synthetic resins. It is also used as an intermediate in the produetion of mesityl oxide, methyl isobutyl ketone and hexylene glycol. 

HPN is produced by the disproportionation of two molecules of hydroxypivalde-hyde in the presence of a basic catalyst such as calcium hydroxide [31.27]. HPN is used as a diol modification agent in polyesters, polyurethanes and plasticisers. It is also used as a component of polyester-varnish systems. 

Pentaerythritol is produced by reacting acetaldehyde with formaldehyde in the presence of calcium hydroxide (or caustic soda) [31.27]. Pentaerythritol is used in the production of alkyd resins. 

Some 80 % of anthraquinone dyes are prepared via the anthraquinone sulfonic acids. In producing certain dyes, the sulfonic acid group is replaced by a hydroxyl group using high pressure fusion with lime [31.28]. 

Trichloroethylene (widely used as a vapour degreasing solvent in the metal-working industries) may be produced from tetrachloroethane by cracking, using milk of lime (33.27). 

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On acetylation it gives acetanilide. Nitrated with some decomposition to a mixture of 2-and 4-nitroanilines. It is basic and gives water-soluble salts with mineral acids. Heating aniline sulphate at 190 C gives sulphanilic add. When heated with alkyl chlorides or aliphatic alcohols mono- and di-alkyl derivatives are obtained, e.g. dimethylaniline. Treatment with trichloroethylene gives phenylglycine. With glycerol and sulphuric acid (Skraup s reaction) quinoline is obtained, while quinaldine can be prepared by the reaction between aniline, paraldehyde and hydrochloric acid. 

Most of the ethylene dichloride produced is utilized for the manufacture of vinyl chloride, which may be obtained from it by pyrolysis or the action of caustic soda. Large quantities are also used in anti-knock additives for gasoline. As a solvent It has been displaced by trichloroethylene and tetrachloroelhyJene. U.S. production 1978 4-75 megatonnes. 

Trichloroethylene is manufactured by the dehydrochlorination of tetrachloroelhane derived from the chlorination of ethyne with lime or by vapour phase cracking. 

Trichloroethylene is not attacked by dilute acids or alkalis, but when heated with sodium hydroxide under pressure it yields sodium gly-collate. In the presence of light and oxygen dichloroethanoyl chloride is formed, which can react with any moisture present to give small amounts of highly corrosive HCl. Numerous stabilizers have been patented. 

Most of the trichloroethylene produced is used for metal degreasing. Other important uses are in the scouring of wool and as an extractive solvent, e.g. for olive and soya bean oils. Minor uses are as a heat transfer medium, anaesthetic, insecticide and fumigant, paint remover and fire extinguisher. 

Trilene A trade name for trichloroethylene when used as an anaesthetic. It is given by inhalation for short operative procedures. 

This measurement provides a definition of the bitumen content in bitumen materials as the portion soluble in carbon disulfide (in France, in trichloroethylene, carbon tetrachloride or tetrachloroethylene). The method is defined by AFNOR NF T 66-012 or IP 47, or ASTM D 4 (the latter is not equivalent to the others). 

Carbon tetrachloride Ethylene chloride. Trichloroethylene. Propylene chloride. Ethylene chlorobromide 1 1 2-Trichloroethane Trimethylene chloride Tetrachloroethylene Trimethylene chlorobromide sym. Tetrachloroethane 1 4 Dichlorobutane 1 2 3-Trichloropropane Pentachloroothane. ... 

Methane has also been used in aerobic bioreactors that are part of a pump-and-treat operation, and toluene and phenol have also been used as co-substrates at the pilot scale (29). Anaerobic reactors have also been developed for treating trichloroethylene. Eor example, Wu and co-workers (30) have developed a successful upflow anaerobic methanogenic bioreactor that converts trichloroethylene and several other halogenated compounds to ethylene. 

Chloroacetic acid forms a2eotropes with a number of organic compounds. It can be recrystaUized from chlorinated hydrocarbons such as trichloroethylene, perchloroethylene, and carbon tetrachloride. The freezing poiat of aqueous chloroacetic acid is shown ia Figure 1. 

Manufacture. Most chloroacetic acid is produced by the chlorination of acetic acid using a suitable catalyst such as acetic anhydride (9—12). The remainder is produced by the hydrolysis of trichloroethylene with sulfuric acid (13,14) or by reaction of chloroacetyl chloride with water. 

Chloroacetyl chloride is manufactured by reaction of chloroacetic acid with chlorinating agents such as phosphoms oxychloride, phosphoms trichloride, sulfuryl chloride, or phosgene (42—44). Various catalysts have been used to promote the reaction. Chloroacetyl chloride is also produced by chlorination of acetyl chloride (45—47), the oxidation of 1,1-dichloroethene (48,49), and the addition of chlorine to ketene (50,51). Dichloroacetyl and trichloroacetyl chloride are produced by oxidation of trichloroethylene or tetrachloroethylene, respectively. 

Chlorinated Solvents. Originally, successive chlorination and dehydro-chlorination of acetylene was the route to trichloroethylene [79-01-6], C2HCI3, and perchloroethylene [127-18-4], C2C1. ... 

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