Short-term exposure can cause irritation of the nose and throat and central nervous system (CNS) depression with symptoms such as drowsiness, dizziness, giddiness, headache, nausea, loss of coordination, confusion and unconsciousness. Deaths have occurred following exposure to very high vapour concentrations. Tetrachloroethylene is heavier than air and can accumulate in low lying areas.

Exposure to 100-200 ppm for 5-7 hours has produced headaches, drowsiness, dizziness and sleepiness. Nose and throat irritation have been reported at 200 ppm and above. Exposure to 280 ppm for 2 hours or 600 ppm for 10 minutes has produced incoordination. Intolerable irritation of the nose and throat has been observed at 1000 ppm and above. Faintness and dizziness were experienced during 2-hour exposures to 1000-1500 ppm. A 5-7 minute exposure to 2000 ppm caused volunteers to feel as though they were going to collapse. A few deaths have been reported due to CNS depression and irregular heart beat. In one case, pulmonary edema (a potentially fatal accumulation of fluid in the lungs) was reported. Liver and kidney injury has also been observed following exposure to very high concentrations which also caused significant CNS effects.

Behaviourial effects (e.g. slow reaction time to visual stimuli and coordination) have been reported in volunteers exposed to concentrations as low as 50 ppm for 4 hours/day for 4 days or 100 ppm and above for several hours. Behaviourial effects were not observed in volunteers exposed to 25 or 100 ppm for 5.5 hours.

Tetrachloroethylene is a severe skin irritant, based on limited human information and animal evidence. A burning sensation and marked redness was reported in individuals who immersed their thumbs in tetrachloroethylene for 30 minutes. Prolonged exposure (more than 5 hours) has caused redness, blistering, and shedding of skin.

Animal and human information indicates that tetrachloroethylene absorption through the skin is minimal. Harmful effects are not expected to occur by this route of exposure.

Liquid tetrachloroethylene is probably a mild eye irritant, based on animal information. Volunteers exposed to 101-216 ppm of tetrachloroethylene vapour have experienced mild eye irritation. A burning or stinging sensation was felt after exposure to 280 or 600 ppm and intense irritation occurred at 930 ppm.

Tetrachloroethylene has been used as a medicine and reported side-effects following administration of 4.2 to 6.0 gm include a feeling of drunkenness, vision disturbances and a feeling of exhilaration. In one case, ingestion of 3 mL (approximately 4.9 gm) was reported to cause death. However, the patient had pre-existing medical disorders which likely played a role in his death.

Tetrachloroethylene can probably be aspirated, based on its physical properties. Aspiration is the inhalation of the chemical into the lungs during ingestion or vomiting. Severe lung irritation, damage to the lung tissues and death may result. Ingestion is not a typical route of occupational exposure.

SKIN EFFECTS: Repeated or prolonged contact is expected to cause red, itchy, dry and cracked skin (dermatitis).

CENTRAL NERVOUS SYSTEM (CNS) EFFECTS: Numerous studies have reported effects on the CNS following long-term occupational exposure to tetrachloroethylene and other solvents. Symptoms such as dizziness, forgetfulness, inability to concentrate, mood swings, nausea and fatigue and behaviourial effects such as reduced reaction time and incoordination have been described. This condition is sometimes generally referred to as "organic solvent syndrome". Many of the available studies are limited by factors such as exposure to other solvents at the same time, incomplete or no exposure information, and evaluation of only a small number of people. Commonly, tetrachloroethylene exposures have occurred in the dry cleaning industry where there would normally be exposure to other solvents. Therefore, it is difficult to directly associate the observed effects to tetrachloroethylene exposure. In one controlled study using volunteers, exposure to 100 ppm for 11 weeks produced decreased coordination. Similar effects were not observed at 20 ppm.

KIDNEY AND LIVER EFFECTS: The available studies of people with long-term occupational exposure are limited by the fact that exposure to other potentially harmful chemicals may have occurred at the same time and the number of people evaluated is relatively small. In a controlled study using volunteers, no signs of liver or kidney injury were observed following exposure to up to 100 ppm over 11 weeks. Kidney and liver effects were also not observed in people with long-term occupational to approximately 20 ppm. A few occupational studies have shown evidence of minor liver and kidney effects following exposure to 10-20 ppm. In another study, 3 of 7 workers exposed to 232-385 ppm tetrachloroethylene had signs of liver damage.

EFFECTS ON THE HEART: In a controlled study using volunteers, no harmful effects on the electrical activity of the heart were observed following exposure to up to 100 ppm tetrachloroethylene, over 11 weeks. In a single case report, an employee exposed to tetrachloroethylene for 7 months developed an irregular heartbeat, which returned to normal after exposure stopped.

Several human population studies have shown more esophageal cancer, non-Hodgkin's lymphoma and cervical cancer in people occupationally exposed to tetrachloroethylene. The International Agency for Research on Cancer (IARC) has concluded that there is limited evidence for the carcinogenicity of tetrachloroethylene in humans. There is sufficient evidence for carcinogenicity in animals. The overall IARC classification is that tetrachloroethylene is probably carcinogenic to humans (Group 2A). The US National Toxicology Program has listed tetrachloroethylene as a substance which may be reasonably anticipated to be a carcinogen.

Tetrachloroethylene has not been shown to cause reproductive toxicity in men. One study reported subtle changes in sperm quality in employees exposed to elevated levels of tetrachloroethylene. In other studies, partners of men occupationally exposed to tetrachloroethylene did not experience decreased fertility or an increase in miscarriages.

One survey suggests that women exposed to tetrachloroethylene may have menstrual disorders. This study is limited by factors such as a small sample size, possible multiple chemical exposures, no assessment of exposure and possible self-reporting bias. In another study, women with long-term exposure to tetrachloroethylene (average levels of 15 ppm) had increased levels of the hormone prolactin in the blood during part of the menstrual cycle. This effect is not likely biologically significant.

The small number of animal studies available have not shown effects on fertility.

A number of human population studies have evaluated the effects of exposure to chemicals in the laundry and dry cleaning industry on pregnancy. Exposure to tetrachloroethylene commonly occurs in this industry. None of the studies have shown an increase in birth defects or stillbirths or decreased weight of the newborn child. A few studies have shown an association with increased miscarriage rates, while others did not. It is not yet possible to draw firm conclusions from the available information because of limitations in the study design such exposure to other chemicals at the same time, lack of exposure information, self-reporting biases and the relatively small number of people studied.

One case report describes jaundice and an enlarged liver in a 6-week old infant exposed to tetrachloroethylene in its mother's breast milk. The mother did experience other harmful effects (for example, dizziness) during exposure. The infant recovered once exposure stopped.

Harmful effects have only been observed in the offspring of animals in the presence of significant harmful effects in the mothers.

Interactive effects, such as synergism, with other chemicals have been examined in a small number of studies. In behaviourial tests with volunteers, no interactive effects were observed when people were exposed to tetrachloroethylene and ethanol, or tetrachloroethylene and the prescription drug, diazepam. In rats, short-term inhalation or oral exposure to tetrachloroethylene, in combination with two other solvents (acetone and ethylene dichloride) did not indicate chemical interactions. In another study with rats, short-term oral exposure to tetrachloroethylene in combination with other chemicals (polyethylene glycol, butyl ether dioxane or acetophenone) indicated that chemical interactions were occurring.

Tetrachloroethylene is rapidly absorbed following inhalation and ingestion. A small amount is absorbed through the skin. It is rapidly distributed throughout the body. Most tetrachloroethylene (80-100% in humans) is eliminated unchanged in exhaled breath. Some is broken down in the body to other chemicals including trichloroacetic acid and trichloroethanol. Most of the metabolites (1-3%) are excreted in the urine in a few days. Some of the absorbed tetrachloroethylene is stored in body fat and may remain for several days or weeks before it is eliminated.