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1,1,1-trichloroethaneReportTo read the report please click here. This marine risk assessment was also published in a peer-reviewed journal: De Rooij, C. et al., 2004. 1,1,1-Trichloroethane Marine Risk Assessment with Special Reference to the OSPARCOM region: North Sea. Environmental Monitoring and Assessment, Vol. 97, (1-3), 39-56. SummaryCurrent usage of 1,1,1-trichloroethane does not represent a risk to the marine environment. This conclusion is based on 32 laboratory toxicity studies, plus 1990-1996 monitoring results from the North Sea, rivers and estuaries. Applications of 1,1,1-trichloroethaneWorld production of 1,1,1-trichloroethane was estimated at 600,000 t in 1995. It was used extensively in metal cleaning (40% of total consumption) and in aerosols, adhesives, coatings, dry-cleaning and textile processing and electronics [European Chlorinated Solvent Association (ECSA), 1996]. 1,1,1-trichloroethane is being phased out for most uses because of its ozone depletion potential (ODP) in the upper atmosphere. Under the Montreal Protocol, production for emissive uses was phased out end 1995 in Europe and 1996 in the US, Japan and other industrialised countries. The main current use of 1,1,1-trichloroethane is as feedstock for HCFC 141b, HCFC 142 b, other CFC substitutes and fluoropolymer resins. It is permitted for "essential uses," such as certain laboratory, analytical and pharmaceutical applications. It is generally produced from ethylene dichloride or 1,1,2-trichlorethane, which is then dehydrochlorinated to 1,1-dichloroethylene. In a further step, 1,1-dichloroethylene is hydrochlorinated to 1,1,1-trichloroethane. 1,1,1-trichloroethane is also produced from EDC via vinyl chloride, which is reacted catalytically with hydrogen chloride to produce 1,1-dichloroethane. This is then converted to 1,1,1-trichloroethane by chlorination. Total emissions of 1,1,1-trichloroethane to water from sites using it as feedstock was estimated at 810 kg in 1995. This figure should have been reduced in 1996 as the main production plants were closed in Europe. Evaluation of environmental riskToxicity For 1,1,1-trichloroethane, 14 data for fish, 9 data for invertebrates and 9 data for algae were evaluated according to the quality criteria recommended by EU authorities. Both acute and chronic toxicity studies were taken into account and appropriate assessment factors were been used to define a final PNEC value of 21 µg/l. Monitoring data Most of the monitoring data apply to river and estuary waters. Data came from the Weser estuary (Germany); Rhine/Maas estuary and North Sea Coast (Netherlands); Tees, Tyne and Solent estuaries and English Channel (UK); the North Sea; and major rivers from industrial areas flowing into the North Sea, such as the Rhine and Mersey. The most recent data (1990-96) support a typical PEC for 1,1,1-trichloroethane of 0.024 µg/l and a worst case PEC of 0.6 µg/l. Data on persistence indicate a half-life in water of a few hours or days. Since bioaccumulation in marine organisms is negligible, current use of 1,1,1-trichloroethane does not represent a risk to the aquatic environment. Risk assessment conclusionWhen the environmental concentration of 1,1,1-trichloroethane is compared with the probable no-effect level to give the PEC/PNEC ratio, there is a safety factor of 35-1000 between actual exposure and the predicted no effect concentration. Dilution within the sea would increase these safety margins. Moreover, environmental levels are expected to have fallen further since the restriction on the use of 1,1,1-trichloroethane in 1996. Risk assessment conclusion for 1,1,1-trichloroethane
North Sea monitoring data on 1,1,1-trichloroethane
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