Trichloroethylene and Cancer

Trichloroethylene, or TCE, is a solvent used to clean and degrease metal parts. Workers who breathe it have the most exposure. So do communities whose water is contaminated. TCE is a known cause of kidney cancer, and the EPA has moved to ban most uses of it.

Trichloroethylene is a colorless liquid. Industry uses it to degrease metal and to make other chemicals. It is a common groundwater contaminant near industrial and military sites. Unlike the related solvent perc, TCE sits in the strongest evidence category, Group 1, for kidney cancer.

In December 2024 the EPA issued a final rule prohibiting most uses of TCE. Some compliance dates have since been extended, and parts of the rule are under review.

TCE reaches people in three main ways:

• Working with metal degreasing or in chemical manufacturing.
• Drinking or bathing in TCE-contaminated water near some sites.
• Breathing vapors that rise from contaminated groundwater into buildings.

TCE is a known cause of kidney cancer. NCI adds that some evidence suggests it may also raise the risk of non-Hodgkin lymphoma and, possibly, liver cancer.

The World Health Organization's cancer agency, the International Agency for Research on Cancer (IARC), places trichloroethylene in Group 1, carcinogenic to humans. That is the strongest evidence category. It means there is enough evidence that TCE can cause cancer in people. The US National Toxicology Program reaches the same conclusion, listing trichloroethylene as known to be a human carcinogen in its Report on Carcinogens.

A Group 1 listing tells you about hazard: TCE is able to cause cancer under some conditions. It does not tell you your own risk. Risk depends on how much TCE you take in, for how long, and on other factors.

Think of a worker who degreased metal with TCE for years. Now think of someone who lives far from any TCE site. The label is the same for both, but their risks are far apart.

• Support cleanup and monitoring of contaminated groundwater sites.
• Use ventilation and protective equipment in industries that use TCE.
• Filter or switch water sources where contamination is found.
• Follow the EPA restrictions that now apply to most TCE uses.

Cutting your own contact with TCE is one piece of a much bigger picture. For the rest of that picture, read our overview of cancer prevention and what raises cancer risk.

Trichloroethylene is a known human carcinogen (IARC Group 1). For most people, the question is whether their job, water, or building could expose them. If it could, ask about testing and ways to cut that exposure.