Trichloroethylene (TCE)

The recent declaration of carcinogenic potential by the US EPA regarding the widely used industrial solvent trichloroethylene (TCE) has grabbed the attention of the cancer community and urged a closer look at this solvent.

What is TCE?

TCE is a nonflammable, colorless liquid. It has a slightly sweet odor. It is said to taste sweet, but also burning.

TCE has several industrial applications, chiefly as a solvent that removes grease from metal, but it also acts as an ingredient in other things that remove things, such as spot removers and paint removers. When you breathe or ingest TCE, it can severely damage the lungs, liver, and nervous system; it can lead to coma, to an abnormal heartbeat, and even death.

Despite not occurring naturally, TCE has been found at over 850 sites on the EPA's 1430 National Priorities List sites. Companies that manufacture, use and dispose of TCE are likely responsible for its appearance in places like water sources. Despite the fact that some TCE will dissolve in water, much of it can stay in water for extended lengths of time, and when it evaporates from surface water it becomes a vapor that pollutes the air and sticks to certain surfaces.

Human exposure to TCE

Exposure to TCE can occur through exposure to the chemical in the air, in shower water, and through use of household products containing TCE. Coming into contact with contaminated soil, water, or air can result in unsafe exposure to TCE.

Mere skin contact will likely result in nothing more than a skin rash.

Breathing TCE however can lead to headaches, lung irritation, dizziness, poor coordination, difficulty concentrating, impaired heart function, unconsciousness, and death. Breathing it for long periods may cause nerve, kidney, and liver damage—all depending on the amount that is inhaled.

Drinking TCE can cause nausea, liver damage, unconsciousness, impaired heart function, liver and kidney damage, impaired immune system function, impaired fetal development in pregnant women, or even death—all depending on the amount that is ingested.

TCE as a human carcinogen

Can extended exposure to TCE cause cancer? Here's what two major agencies have to say on the matter:

-- The National Toxicology Program (NTP): Trichloroethylene is "reasonably anticipated to be a human carcinogen."
-- The International Agency for Research on Cancer (IARC): Trichloroethylene is "probably carcinogenic to humans."
-- The US EPA "characterizes [TCE] as carcinogenic to humans."

Sources

CDC page: Trichloroethylene
Agency for Toxic Substances & Disease Registry: FAQ for Trichloroethylene