Trichloroethylene (TRI)

TRI, Trikloreten (C2HCl3)


Trichloroethylene (TRI)

CAS no


Chemical formula


 Trichloroethylene belongs to the group volatile organic compounds (VOC) and is a colourless, volatile liquid with a sweet, aromatic odour.1


Trichloroethylene is primarily used in the production of other chemicals, such as 1,1,1,2-tetrafluoroethane (HFC-134a) and as a solvent for removal of grease from metal.

The substance has in the past also been used as an extraction solvent for fats, within the textile industry, in dry cleaning and for other purposes.2 3 It was previously subject to a national, Swedish ban and since 2016, exemption to the ban must be applied for through the EU. Trichloroethylene is allowed to be used professionally for research and development purposes and for laboratory work.4

Sources and transportation pathways

Chemical industry, landfills, surface treatment and production of paper and wood products are the main point sources of trichloroethylene emissions in Europe.5 The substance degrades quickly in air. In water it degrades slowly and evaporates to the most part to air. It can reach the groundwater from contaminated surface water and will stay there for a considerable amount of time. Trichloroethylene may also reach the groundwater through soil. In soil, it degrades slowly and most of it evaporates to air.6

Effects on environment and health

Trichloroethylene is not acutely toxic to humans. It biomagnifies in nature and is toxic to aquatic systems.7 As a VOC, trichloroethylene can be involved in the formation of ground-level ozone. Ground-level ozone may damage vegetation and during episodes of elevated VOC levels, it may cause irritation of the respiratory tract in humans.

Inhalation of its fumes and skin contact can result in poisoning. Heating of the substance gives rise to poisonous and corrosive gases.8 Exposure to large amounts of trichloroethylene can affect the nervous system, heart, liver and kidneys, and may cause coma or even death. Smaller amounts of the substance may cause headache, dizziness and fatigue. Trichloroethylene is an endocrine disruptor and a carcinogen.9

International agreements and regulations

Trichloroethylene is regulated by the EU Water Framework Directive (2000/60/EC), the EU Groundwater Directive (2006/118/EC) and the EU Drinking Water Directive (98/83/EC). The presence of trichloroethylene in products is regulated by the EU regulation on cosmetic products (EC 1223/2009). The UN Protocol on PRTRs and the EU E-PRTR regulation regulate how data on trichloroethylene emissions is made available.

As a VOC, trichloroethylene is indirectly regulated by the UN Convention on Long-Range Transboundary Air Pollution (CLRTAP) and the EU Framework Convention on Climate Change (UNFCCC), as well as by the EU National Emissions Ceilings Directive (2001/81/EC) and the EU Industrial Emissions Directive (2010/75/EU).


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