National Industrial Chemicals Notification and Assessment Scheme
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- 2.2International perspective
- 2.2.1United States
- 2.2.2European Union
- 2.3Australian perspective
2.Background2.1HistoryTrichloroethylene was first prepared in 1864 by Fischer by the reduction of hexachloroethane with hydrogen. Commercial production of trichloroethylene in Europe started in 1908 and in the USA in the 1920s. In the past, as is today, trichloroethylene has mainly been used as a liquid or vapour degreasing solvent in the metal fabricating industry. International and national concern about the environmental and health and safety implications of chlorinated solvents has resulted in a number of regulations and controls that have impacted on the use of trichloroethylene. 2.2International perspectiveIn general, there has been a continuing decline in demand for trichloroethylene over the years. New growth is possible in future due to concerns with some of the alternatives for trichloroethylene, for example the phasing out of 1,1,1-trichloroethane at the end of 1995 under the Montreal Protocol. Overseas, new growth in use has also been seen because of its use as a precursor in the manufacture of chlorofluorocarbons (CFC) alternatives such as HFC-134a or HCFC-123 (Anon, 1995). However, conversely, increasing trends in the recovery and recycling of trichloroethylene may reduce production of trichloroethylene. Such circumstances could introduce new sources of potential exposure. 2.2.1United StatesSevere restrictions by the US government in the use and emission of trichloroethylene led to a decrease in demand for trichloroethylene (Wolf & Chestnutt, 1987). The restrictions were as follows: In 1968, Los Angeles County adopted Rule 66 which limited emissions of trichloroethylene. By 1972, several other states enacted legislation similar to L.A. County’s Rule 66. The original US Clean Air Act (1970) which regulated emissions of chlorinated solvents like trichloroethylene led to the chemical’s replacement with 1,1,1-trichloroethane by many users (Shelley et al., 1993). In 1974 conversion from trichloroethylene to 1,1,1-trichloroethane proceeded rapidly in solvent and degreasing applications to comply with air pollution standards. By 1975, industry agreed that trichloroethylene was photoreactive and Federal and local governments severely restricted the use and emission of trichloroethylene in vapour degreasing plants in many areas of the country to reduce air pollution. In 1977, the US Environmental Protection Agency’s recommended policy on the control of volatile organic compounds was announced and trichloroethylene was listed as photochemically reactive. Another event that contributed to the decline in demand was a “Memorandum of alert” issued on trichloroethylene by the US National Cancer Institute in April 1975. Preliminary findings in bioassays of the solvent indicated that it had carcinogenic effects in mice. The alert resulted in a push for replacement by “safer” solvents such as tetrachloroethylene (perchloroethylene) and 1,1,1-trichloroethane. The findings of photoreactivity and potential carcinogenicity of trichloroethylene led to a decline in production. For example, in the USA the demand for trichloroethylene dropped from 244,939 tons (540 million pounds) in 1971 to only 68,038 tons (150 million pounds) in 1990. Refer to Figure 1. Figure 1 - Annual chlorinated solvents production (Wolf & Chestnutt, 1987) 
perchloroethylene methylene chloride trichloroethylene methyl chloroform x CF113
More recently, in 1991 Sweden issued an Ordinance which banned the sale, transfer or use of chemical products containing trichloroethylene, methylene chloride, or tetrachloroethylene. The bans came into force with respect to consumer use on 1 January 1993 and with respect to professional use (with the exception of tetrachloroethylene which was not included in this ban) from 1 January 1996. The decision to ban was based on the hazards to health posed by these compounds and the fact that they were being used in very large quantities. Factors taken into account when banning trichloroethylene were the volatility of the chemical and the assessment that a limitation or control on trichloroethylene was not enough to ensure people were not exposed. The fact that trichloroethylene use was widespread among small companies, and that knowledge on how to protect people from exposure differed, were factors taken into consideration. In addition, it was considered that a ban would contribute to development of less harmful substances or techniques. The National Chemicals Inspectorate may issue regulations on exemptions and grant exemptions in individual cases, for instance, trichloroethylene may still be used for research and development and analysis purposes. (European Chemical News, 1995; KEMI, 1995; Cederberg, 1996). 
2.3Australian perspectiveTrichloroethylene was manufactured in Australia for approximately 30 years from the early 1950s to the early 1980s. At present, the Australian market demand for trichloroethylene is entirely met by imports of the chemical. Trichloroethylene is used widely in both large and small industries mainly as a degreasing agent. It is likely that the use of trichloroethylene in Australia has followed the trend seen in the US and worldwide. Information suggests that several years ago many users changed from using trichloroethylene to 1,1,1-trichloroethane due to the potential carcinogenicity of trichloroethylene. Import data obtained from the ABS show an increase in trichloroethylene imports from 1994 to 1996. This could probably be attributed to the phase out of 1,1,1-trichloroethane and substitution with trichloroethylene. Table 1 shows amounts of trichloroethylene imported from 1988 to 1997. Table 1 -Trichloroethylene imported into Australia
Australia has adopted the Montreal Protocol leading to the phasing out of 1,1,1- trichloroethane. It is therefore likely that trichloroethylene will replace the chemical for some of its uses, resulting in an increase in demand. This may be balanced by increasing trends to recycle trichloroethylene. Directory: data -> assets -> word doc -> 0017 word doc -> Rail safety news issue 6 – October 2011 word doc -> Review of Multiple Chemical Sensitivity: Identifying word doc -> Board Endorsed October 2009 amended 13-09-11 with extra units 0017 -> Rail Safety News Edition 8, December 2012 0017 -> Commonwealth of Australia 2010 0017 -> Real-Time License Plate Localisation on fpga 0017 -> Careers network bulletin issue 6 July 16 2012 0017 -> Wiser science: Finding References inspec for Physics and Engineering 0017 -> Part A: Depth Study: The globalising world Popular culture and public policy Download 1.35 Mb. Share with your friends:
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