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Trichloroethylene

trichloroethene

SPRI Emission Reporting Threshold
1,000 Kg/yr Pollutant Emissions to Air
1.00 Kg/yr Pollutant Emissions to Waste Water
1.00 Kg/yr Pollutant Emissions to Water
Disclaimer
This sheet is a generic summary, designed to give the reader a basic level of background information about the substance in question. Great care has been taken to represent as effectively and correctly as possible the broad range of (not necessarily consistent) information which is available from a variety of sources. The reader must accept therefore that this sheet has no legal status and cannot be relied upon in any legal proceedings. SEPA disclaims any responsibility or liability whatsoever for errors and omissions in this sheet.
What is it?
Trichloroethylene (TRI) is a thick, colourless liquid, with a sweet smell. It dissolves only slightly in water, but evaporates easily. It is virtually non-flammable and non-corrosive. TRI is part of the group of compounds known as the volatile organic compounds (VOCs).
What is it used for?
The main uses of TRI are as a metal degreasing agent, as a solvent (in paints and lubricants), in the manufacture of chemicals, in adhesives and as a refrigerant and heat exchange fluid. In the past it was also used as a grain fumigant and as an anaesthetic.
Where does it come from?
Releases of TRI occur from sites manufacturing, using and disposing of the chemical or products containing it. High levels are released during extreme accidental spillages. TRI is a man-made substance - there are no natural sources to the environment.
How might it affect the environment?
TRI is found widely in the environment, but usually at low levels which are unlikely to harm wildlife or plants. It quickly evaporates into the air from water, but can bind to soils for long periods. It does not accumulate significantly in animals or plants. Extreme high-level exposure (following a spillage for example) is however toxic to aquatic and terrestrial organisms. As a VOC it may contribute to the formation of ground level ozone or photochemical smogs which can damage crops and materials. It is not thought likely that TRI has any environmental effects at a global level.
How might exposure to it affect human health?
Exposure to normal environmental concentrations of TRI is unlikely to significantly damage health. Higher level exposures (both over a prolonged period in an occupational setting or as a result of a one-off accidental release) may however possibly be carcinogenic and have been observed to cause nausea, headaches, dizziness, drowsiness (possibly leading to unconsciousness), irregular heartbeat, depression of the central nervous system and even death. Inhalation of ground level ozone (in the formation of which TRI can be involved) can exacerbate respiratory conditions such as asthma.
What steps are being taken to limit the potential impacts?
In the UK (including Scotland) TRI releases are controlled by regulations on pollution of surface waters; the Pollution, Prevention and Control (PPC) regulations; the Food and Environmental Protection Act (FEPA 1985); the Control of Pesticides Regulations (COPR 1986); and it is not listed as a safe pesticide for use in the UK. European Directives controlling emissions of TRI include those concerned with pollution of the aquatic environment (76/464); and control of solvent releases. Internationally, TRI is regulated (as a VOC) by the UNECE convention on long-range transboundary air pollution; the Basel convention on transboundary movement and disposal of hazardous wastes; and it is listed as a candidate substance for inclusion under the OSPAR and Helsinki conventions which protect the marine environments of the north-east Atlantic and the Baltic sea respectively.