Perchloroethylene(PERC) is the most commonly used dry-cleaning solvent. P.E.R.C. can enter the body through respiratory and dermal (skin) exposure. Symptoms associated with exposure include: depression of the central nervous system, damage to the liver and kidneys, impaired memory, confusion, dizziness, headache, drowsiness and eye, nose and throat irritation. Repeated dermal exposure may result in dermatitis. The National Institute Occupational Safety and Health (NIOSH) considers PERC a potential human carcinogen.
Tetrachloroethylene, also known under its chemical name tetrachloroethene and many other names, is a colorless liquid widely used for the dry cleaning of fabrics, sometimes referred to by its more popular name of “dry-cleaning fluid.” It has a sweet odor that detectable by most people at a concentration of 1 part per million.
Tetrachloroethylene is an excellent solvent for organic materials. Otherwise it is volatile, highly stable and nonflammable. For these reasons, it is widely used in dry cleaning and is more commonly known as PERC. It appears in a few consumer products including paint strippers and spot removers.
The International Agency for Research on Cancer (IARC) classified tetrachloroethene as a Group 2A carcinogen, which means that it is probably carcinogenic to humans. Like many similar chlorinated hydrocarbons, tetrachloroethene is a central nervous system depressant and can enter the body through respiratory or dermal (skin) exposure. Tetrachloroethene dissolves fats from the skin potentially resulting in skin irritation.
Various animal studies, plus a study of 99 twins by Dr. Samuel Goldman and researchers at the Parkinson’s Institute in Sunnyvale, California determined there is a “lot of circumstantial evidence” that exposure to tetrachloroethlene increases the risk of developing Parkinson’s disease nine fold. Larger population studies are planned.
Tetrachloroethene exposure can be evaluated by a breath test similar to a breathalyzer test for alcoholic intake. Because it is stored in the body’s fat and slowly released into the bloodstream, tetrachloroethene can be detected in the breath for weeks following a heavy exposure. Tetrachloroethylene and trichloroacetic acid (TCA), a breakdown product of tetrachloroethene, can be detected in the blood.
It is estimated that, through processing, roughly 85% of tetrachloroethylene is released into the atmosphere. Some measurements assume 90% of that is released into the air and 10% into the water. Tetrachloroethene is a common soil contaminant. Because of the mobility of PCE in groundwater, its toxicity at low levels and its density (which causes it to sink below the water table), cleanup activities are more difficult than cleanup for oil spills. Recent research focused on the in-place remediation of soil and ground water pollution by tetrachloroethylene. Instead of excavation or extraction for above-ground treatment or disposal, tetrachloroethylene contamination is successfully treated through chemical bioremediation. Bioremediation was also found to be successful under certain circumstances. What does this information mean for all of us? Studies show that effects to short term PERC exposure were mild and disappeared soon after exposure ended.
Numerous studies of dry-cleaning workers show that long term exposure (9 to 20 years for example) to PERC in the workplace reduces scores on behavioral tests and causes biochemical changes in blood and urine. Even though these effects were mild and hard to detect, how long these effects would last if exposure ended is still not known. Some studies show a slightly increased risk of some types of cancer and reproductive effects among dry-cleaning workers exposed to PERC and other chemicals. Associated cancers due to exposure include cancers of the esophagus, bladder and non-Hodgkin’s four lymphoma. Cancers less clearly associated with exposures include cancers of the cervix, tongue and lung. The reproductive effects associated with exposure included increased risks ofspontaneous abortion, menstrual and sperm disorders and reduced fertility. The data suggest, but do not prove, that the effects were caused by PERC and not by some other factor or factors. The bottom line: everything in moderation. We’re all inundated by chemicals and toxins in our everyday work and living place. Toxic exposure is a fact of operating in a modern world. Be armed with knowledge about what exists “out there” in our environment, implement personal measures to protect yourself – such as reading Healthy Beginnings Magazine for the latest update on health issues, concerns and resolutions! – then take appropriate action to stay as healthy as humanly possible within your resources and means!
- “Control of Exposure to Perchloroethylene in Commercial Drycleaning,” Hazard Controls: Publication 97-157.
- National Institute for Occupational Safety and Health; http://www.cdc.gov/niosh/