SPRI Home About SPRI

Methyl chloroform

1,1,1-trichloroethane, Methyl chloroform

SPRI Emission Reporting Threshold
10.0 Kg/yr Pollutant Emissions to Air
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?
Trichloroethane 1,1,1 (TCE) is a colourless liquid or vapour with a sharp sweet smell. It dissolves in water and other chemicals and easily evaporates into the air. TCE is non-flammable.
What is it used for?
TCE used to be widely used as a solvent and degreasing agent. It is now used less in industry and only occasionally in domestic products such as spot cleaners, glues and aerosol sprays.
Where does it come from?
Significant amounts of TCE used to be released from its formerly widespread use as a solvent - particularly in indoor environments. Today, small amounts are released from chemical processes, waste treatments and from domestic products. TCE is a man-made chemical - there are not thought to be any natural sources to the environment. Most releases evaporate into the atmosphere, but it can also contaminate water bodies.
How might it affect the environment?
TCE readily evaporates into the atmosphere. It does not bind to soils or sediments but can contaminate water bodies and accumulate in aquatic life. Normal environmental levels are unlikely to damage the local environment. However, higher levels resulting from spillages are toxic. As a VOC it does not play a significant role in the formation of potentially damaging ground level ozone. In the upper atmosphere however, it can damage the stratospheric ozone layer and hence reduce the protection from harmful UV sun rays which this offers.
How might exposure to it affect human health?
Exposure to normal environmental concentrations of TCE is unlikely to damage health. Exposure to high levels following an accidental release or in occupational settings might however cause dizziness and loss of balance, irritation of the skin, eyes and respiratory tract (air passages and lungs) and damage to the heart, kidneys and central nervous system. Long-term exposure to less extreme levels may damage the liver. Depletion of the stratospheric ozone layer (in which TCE plays a part) means that humans may be exposed to higher doses of UV sunlight which might cause skin cancers.
What steps are being taken to limit the potential impacts?
In the UK (including Scotland) releases of TCE are controlled through regulations on pollution of surface waters; and the National Air Quality Strategy (as a VOC). European Directives controlling emissions of TCE include those concerned with reduction of stratospheric ozone depleting substances (3093/94); and restrictions on the use and manufacture of certain substances (2037/2000). Internationally, releases of TCE are controlled through the UNECE convention on long-range transboundary air pollution; the Basel convention on transboundary movements and disposal of hazardous wastes; the Montreal protocol on substances that deplete the stratospheric ozone layer; and it is listed as a candidate substance for inclusion under the Helsinki convention which protects the marine environment of the Baltic sea.