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Chloroform

chloroform

SPRI Emission Reporting Threshold
100 Kg/yr Pollutant Emissions to Air
5.00 Kg/yr Pollutant Emissions to Water
5.00 Kg/yr Pollutant Emissions to Waste 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?
Trichloromethane (chloroform) is a clear, colourless liquid with a distinctive smell. It evaporates into air easily and is non-flammable. It does not dissolve well in water, but mixes well with most organic (carbon-containing) solvents.
What is it used for?
The main use of chloroform is as a solvent and as an intermediate in the manufacture of chemicals such as pesticides. In the past it was used as an anaesthetic.
Where does it come from?
Major releases of chloroform are likely to occur from industrial sites producing or using it in chemical processes. Smaller amounts might be released as a result of the chlorination of drinking water, sewage treatment and from some agricultural products in which it is used as a solvent. Chloroform is a man-made chemical - there are thought to be no natural sources.
How might it affect the environment?
At normal environmental concentrations chloroform is unlikely to harm the environment. Extremely high levels (following an accidental spillage for example) may however cause damage. Although the majority of chloroform released will be evaporated into the atmosphere, some will persist in water bodies but it is not expected to concentrate in the food chain and very little binds to soils or sediments. As a VOC, chloroform may be involved in reactions with other air pollution to form ground level ozone which can damage crops and materials. The fact that chloroform has a long lifetime in the atmosphere (up to months) means that it can be transported long distances to remote and potentially sensitive environments.
How might exposure to it affect human health?
Exposure to normal environmental concentrations of chloroform is unlikely to damage human health. High levels of chloroform are however toxic - hence the discontinuation of its use as an anaesthetic. Long-term exposure to higher levels (likely in occupational settings) can cause damage to the skin, liver, kidneys and nervous system. Inhalation of ground level ozone (in the formation of which chloroform 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) releases of chloroform are controlled through regulations on pollution of surface waters (SI 1997/2560); Pollution, Prevention and Control (PPC) regulations; and as a VOC under the National Air Quality Strategy. European Directives controlling emissions of chloroform include those concerned with pollution of aquatic environments (76/464); evaluation of risks posed by substances (793/93); the marketing and use of certain substances (76/769/EEC); ambient air quality assessment and management (96/55/EEC); control of solvent use (99/13/EC); the hazardous wastes Directive; and is listed as a "priority substance" for the proposed Water Framework Directive. Internationally, releases of chloroform are controlled through the UNECE convention on long-range transboundary air pollution; the Basel convention on transboundary movements and disposal of hazardous wastes; the Helsinki convention which protects the marine environment of the Baltic sea; and is listed as a candidate substance for inclusion under the OSPAR convention to protect the marine environment of the north-east Atlantic.