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Trichlorobenzene - all isomers

including all its isomers

SPRI Emission Reporting Threshold
1.00 Kg/yr Pollutant Emissions to Air
0.01 Kg/yr Pollutant Emissions to Water
0.01 Kg/yr Pollutant Emissions to Waste Water
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?
Trichlorobenzene (TCB) exists in several forms (isomers). These are all colourless liquids with a pleasant smell. They are only slightly soluble in water, but dissolve easily in organic solvents. They are non-flammable and although they have a fairly high boiling point (above 200 degrees celsius), they easily decompose to produce toxic gases when heated. TCBs are part of the group of compounds known as the volatile organic compounds (VOCs).
What is it used for?
The main use of TCBs are in the chemical industry: in the manufacture of dyestuffs and textiles and in synthetic oils. They are also used as lubricants and heat transfer fluids, as wood preservatives, as cleaning agents for septic tanks and in abrasive formulations. In the past they were used in tropical regions of the world as an insecticide against termites.
Where does it come from?
Accidental spillages of TCBs may occur during their manufacture, transport, storage and use. Most of these occur to air, though some will be released to land or water bodies. TCBs are man-made chemicals - there are no natural sources of release to the evironment.
How might it affect the environment?
When released to atmosphere it will degrade by reaction with photochemically produced hydroxyl radicals or wash out with rain, with half-life of 3hours to over one day
How might exposure to it affect human health?
Humans may be exposed to TCBs by ingesting contaminated foods or water. Occupational exposures can also occur. The effects vary depending on the type and level of exposure and the form in question. Potential effects can include irratation of the skin, eyes and respiratory tract, damage to the lungs, liver and kidneys. TCBs can also be stored and persist in the body's fatty tissues. Inhalation of ground level ozone (the formation of which TCBs can be involved in) can exacerbate respiratory conditions such as asthma.
What steps are being taken to limit the potential impacts?
In the UK (including Scotland) the main legislation controlling releases of TCBs are those regulating pollution of surface waters (SI 1997/2560); Pollution Prevention and Control (PPC); the National Air Quality Strategy (as VOCs); and they are "red list" pollutants, highlighting that they are of particular concern in the UK environment. European Directives controlling emissions of TCBs include those covering pollution of the aquatic environment (76/464); treatment of solvents; and it is one of eleven "priority hazardous substances" for the proposed Water Framework Directive. Internationally, TCBs are identified as "priority substances" included in the OSPAR convention which protects the marine environment of the north-east Atlantic; they are included under the Basel convention on transboundary movements and disposal of hazardous wastes; and (as VOCs) they are included in the UNECE convention on long-range transboundary air pollution.