ATSDR TOXZINE

TRICHLOROETHYLENE 

CONTENTS

1 . . . . . . . . . . . . . . Trichloroethylene Overview

2 . . . . . . . . . . . . . . . . . . . . . . . . Trichloroethylene 

and the Environment

3 . . . . . . . . . . . . Exposure to Trichloroethylene

4 . . . . . . . . . . Trichloroethylene and the Body

5 . . . . . . . . . . . . . . . Health Effects of Exposure

7 . . . . . . . . . . . Trichloroethylene and Children

8 . . . . . . . . . . . . . . . Reducing Risk of Exposure

10 . . . . . . . . . . . . . . . . . . . . . . . . . Exposure Testing

11 . . . . . . . . Governmental Recommendations

12 . . . . . . . . . . . . . . . . . . . Additional Information

TRICHLOROETHYLENE 

OVERVIEW 

Trichloroethylene is a colorless, volatile liquid. 

Liquid trichloroethylene evaporates quickly into the air. It is nonflammable and has 

a sweet odor.

The two major uses of trichloroethylene are as a solvent to remove grease from 

metal parts and as a chemical that is used to make other chemicals, especially the 

refrigerant, HFC-134a. Trichloroethylene has also been used as an extraction solvent 

for greases, oils, fats, waxes, and tars; by the textile processing industry to scour 

cotton, wool, and other fabrics; in dry cleaning operations; and as a component of 

adhesives, lubricants, paints, varnishes, paint strippers, pesticides, and cold metal 

cleaners.◆

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TRICHLOROETHYLENE AND 

THE ENVIRONMENT 

Trichloroethylene can be released into the air, water, and soil 

at places where it is produced or used.

Trichloroethylene is commonly found in outdoor air at levels far less than 1 part 

per million (ppm). Trichloroethylene levels of approximately 1–100 

ppm have been measured in workplace air at facilities that use 

trichloroethylene for metal degreasing. Trichloroethylene levels as 

high as 20 parts per billion (ppb) have been measured in air inside 

homes and public places. Trichloroethylene is broken down quickly 

in air. People who live near facilities that use trichloroethylene or 

near hazardous waste sites containing trichloroethylene may have a 

higher exposure to this substance.

Trichloroethylene has been found in drinking water samples at many 

locations in the United States. Levels at these locations are typically 

less than 30 parts per billion (ppb). Trichloroethylene breaks down 

slowly in surface water and is removed mostly through evaporation 

to air. Trichloroethylene can slowly enter groundwater from 

contaminated surface water. Trichloroethylene is expected to remain 

in groundwater for long periods of time since it is not able to readily 

evaporate from groundwater.

Trichloroethylene can also move through soil and contaminate 

groundwater. Trichloroethylene breaks down slowly in soil and is 

removed mostly through evaporation to air. Trichloroethylene in soil 

(and to some extent in groundwater) may evaporate and migrate 

into air spaces beneath buildings to enter the indoor air, a process 

termed vapor intrusion.◆

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EXPOSURE TO 

TRICHLOROETHYLENE

Trichloroethylene can enter your body from the air, water, 

or soil.

You are most likely to be exposed to trichloroethylene by drinking trichloroethylenecontaminated water; you may also be exposed by breathing 

trichloroethylene released to the air from trichloroethylenecontaminated water. If you work in the degreasing industry or other 

industry where trichloroethylene is used, you may be exposed by 

breathing in trichloroethylene-contaminated air or by contacting the 

chemical with your skin.

Trichloroethylene in air can easily enter your body when you 

breathe. Most of the trichloroethylene that you breathe in will go 

into your bloodstream and into other organs. A small amount of 

trichloroethylene in the air can also move through your skin and into 

your bloodstream.

When trichloroethylene is found in water, it can enter your body when 

you drink or touch the water or when you breathe in steam from 

the water. Most of the trichloroethylene that you breathe in or drink 

will move from your stomach or lungs into your bloodstream. When 

you touch water containing trichloroethylene (such as showering or 

bathing with trichloroethylene-contaminated water), some of it can 

get through your skin into your body.

You can also be exposed to trichloroethylene in soil when small 

amounts of soil are transferred to your mouth accidentally, when 

your skin touches the soil, or when you breathe air or dust coming 

from the soil.

Trichloroethylene has been detected in table-ready foods at 

concentrations generally in the range of 2–100 ppb.. ◆
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TRICHLOROETHYLENE 

AND THE BODY 

Once in your blood, your liver changes much of the 

trichloroethylene into other chemicals. 

When the body absorbs more trichloroethylene than it can break down quickly, 

some of the trichloroethylene or its breakdown products can be stored in body 

fat for a brief period. However, once absorption ceases, trichloroethylene and its 

breakdown products quickly leave the fat.

You will quickly breathe out much of the trichloroethylene that reaches your 

bloodstream; most of the trichloroethylene breakdown products leave your body in 

the urine within a day.

The health effects of trichloroethylene depend on how much trichloroethylene 

you are exposed to and the length of that exposure. Environmental monitoring 

data suggest that any trichloroethylene levels the public might encounter by direct 

contact or through air, water, food, or soil, are generally much lower than the levels 

at which adverse effects are elicited in animal studies.◆

You will quickly 

breathe out much of the 

trichloroethylene 

that reaches your 

bloodstream.
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HEALTH EFFECTS

OF EXPOSURE 

Trichloroethylene was once used as an anesthetic for surgery.

People who are overexposed to moderate amounts of trichloroethylene may 

experience headaches, dizziness, and sleepiness; large amounts of trichloroethylene 

may cause coma and even death. Some people who breathe high levels of 

trichloroethylene may develop damage to some of the nerves in the face. Other 

effects seen in people exposed to high levels of trichloroethylene include evidence of 

nervous system effects related to hearing, seeing, and balance, changes in the rhythm 

of the heartbeat, liver damage, and evidence of kidney damage. Some people who 

get concentrated solutions of trichloroethylene on their skin develop rashes.

Relatively short-term exposure of animals to trichloroethylene resulted in harmful 

effects on the nervous system, liver, respiratory system, kidneys, blood, immune 

system, heart, and body weight.

Exposure to trichloroethylene in the workplace may cause scleroderma (a systemic 

autoimmune disease) in some people. Some men occupationally-exposed to 

trichloroethylene and other chemicals showed decreases in sex drive, sperm quality, 

and reproductive hormone levels.
Long-term exposure studies in animals have mainly focused on carcinogenicity and 

relatively insensitive noncancer end points following oral exposure; these studies 

are not helpful in defining noncancer end points in humans following long-term 

exposure. However, depressed body weight and evidence of effects on the thymus 

were reported in one recent study of mice exposed to trichloroethylene via their 

mothers during gestation and lactation and via the drinking water for up to 12 

months thereafter. 

There is strong evidence that trichloroethylene can cause kidney cancer in people 

and some evidence that it causes liver cancer and malignant lymphoma (a blood 

cancer). Lifetime exposure to trichloroethylene resulted in increased liver cancer in 

mice and increased kidney cancer in rats at relatively high exposure levels. There is 

some evidence for trichloroethylene-induced testicular cancer and leukemia in rats 

and lymphomas and lung tumors in mice. ◆

Cancer Determinations 

from Regulatory Agencies 

for Trichloroethylene

National Toxicology Reasonably anticipated to cause cancer in humans. 

Program (NTP) NTP has proposed to reclassify trichloroethylene 

as “known to be a human carcinogen,” but this has not 

been finalized.

International Considers trichloroethylene to be a multisite 

Agency for carcinogen (liver, kidney, lung, testes, and bloodResearch on Cancer producing system) in rats and mice by inhalation 

(IARC) and oral exposure routes. Furthermore, there 

is convincing evidence that trichloroethylene 

exposure can cause kidney cancer in humans.

Environmental There is convincing evidence that trichloroethylene 

Protection Agency exposure can cause kidney cancer in humans

(EPA)

National Research There is “limited/suggestive evidence of an 

Council (NRC) association” between exposure to trichloroethylene 

and risk of kidney cancer and “inadequate/

insufficient evidence to determine whether 

an association exists” between exposure to 

trichloroethylene and risk of cancer at other sites.

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7

TRICHLOROETHYLENE 

AND CHILDREN 

Trichloroethylene is expected to affect children in the same 

manner as adults. 

It is not known whether children are more susceptible 

than adults to the effects of trichloroethylene.

Some human studies indicate that trichloroethylene 

may cause developmental effects such as 

spontaneous abortion, congenital heart defects, 

central nervous system defects, and small birth 

weight. However, these people were exposed to other 

chemicals as well. In some animal studies, exposure 

to trichloroethylene during development may have 

caused effects such as decreased body weight, 

increased incidences of heart defects, functional or 

structural changes in the developing nervous system, 

and effects on the immune system. ◆
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REDUCING RISK 

OF EXPOSURE 

If your doctor finds that you have been exposed to significant 

amounts of trichloroethylene, ask whether your children 

might also be exposed. Your doctor might need to ask your 

state health department to investigate.

Exposure to contaminated drinking water should be limited. Trichloroethylene has 

been detected in some drinking water supplies. For bottled water, consumers should 

contact the bottler with specific questions on potential contaminants.

If you live near an industrial site where trichloroethylene is produced or is a 

byproduct or you live near a hazardous waste site where it has been discarded, there 

may be high levels of trichloroethylene in the water and soil. If you find your home 

water supply and/or soil to be contaminated with trichloroethylene, consider using a 

cleaner source of water and limiting contact with soil (for example, through use of a 

dense ground cover or thick lawn) to reduce exposure to trichloroethylene. Produce 

grown in contaminated soil should not be eaten. By paying careful attention to dust 

and dirt control in the home (air filters, frequent cleaning), you can reduce family 

Make sure 

that children 

wash their hands 

frequently 

and before eating.
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exposure to contaminated dirt. Some children eat a lot of dirt. You should prevent 

your children from eating dirt. You should discourage your children from putting 

objects in their mouths. Make sure that children wash their hands frequently and 

before eating. Discourage your children from putting their hands in their mouths or 

from other hand-to-mouth activity.

Trichloroethylene is widely used as a solvent for extraction, waterless drying, and 

finishing, and as a general purpose solvent in adhesives, lubricants, paints, varnishes, 

paint strippers, pesticides, and cold metal cleaners. Follow instructions on product 

labels to minimize exposure to trichloroethylene. ◆
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EXPOSURE 

TESTING 

Trichloroethylene and its breakdown products (metabolites) 

can be measured in blood and urine.

However, the detection of trichloroethylene or its metabolites cannot predict the kind 

of health effects that might develop from that exposure, partly because exposure 

to other chemicals can produce byproducts similar to those observed following 

exposure to trichloroethylene. Because trichloroethylene and its metabolites leave 

the body fairly rapidly, the tests need to be conducted within a few hours after 

exposure. Tests for trichloroethylene and its metabolites in the blood or urine require 

special analytical equipment not readily available at medical facilities.◆
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Federal Organization Regulation or Recommendation

U.S. Environmental EPA set a maximum contaminant goal (MCL) 

Protection Agency of 0.005 milligrams per liter (mg/L; 5 ppb) 

(U.S. EPA) as a national primary drinking standard for 

trichloroethylene; EPA noted liver problems 

and increased risk of cancer as potential 

health effects from long-term exposure 

above the MCL.

Occupational OSHA set a permissible exposure limit 

Safety and Health (PEL) of 100 ppm for trichloroethylene in 

Administration air averaged over an 8-hour work day, an 

(OSHA) acceptable ceiling concentration of 200 ppm 

provided the 8-hour PEL is not exceeded, 

and an acceptable maximum peak of 300 

ppm for a maximum duration of 5 minutes 

in any 2 hours).

National Institute for NIOSH considers trichloroethylene to be 

Occupational Safety a potential occupational carcinogen and 

and Health (NIOSH) established a recommended exposure limit 

(REL) of 2 ppm (as a 60-minute ceiling) 

during the usage of trichloroethylene as an 

anesthetic agent and 25 ppm (as a 10-hour 

TWA) during all other exposures.

GOVERNMENTAL 

RECOMMENDATIONS 

Recommendations and regulations are also updated 

periodically as more information becomes available. For the 

most current information, check with the federal agency or 

organization that issued the regulation or recommendation. 

Some regulations and recommendations for trichloroethylene include:
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ADDITIONAL 

INFORMATION 

If you have any more questions or concerns, please contact 

your community or state health or environmental quality 

department or contact ATSDR at the address and phone 

number below. 

Agency for Toxic Substances and Disease Registry

Division of Toxicology and Human Health Sciences

1600 Clifton Road NE, Mailstop F-57

Atlanta, GA 30329-4027

Toll-free information and technical assistance:

1-800-CDCINFO (1-800-232-4636)
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ATSDR TOXZINE A publication of CDC/ATSDR

something like: A publication from the Centers for 

Disease Control and Prevention

CS250230-A