The United States Environmental Protection Agency concluded Monday that perchloroethylene does not pose an unreasonable risk to human health when used in metalworking fluids such as cutting oils, while also finding that it does pose an unreasonable risk in other applications.
The conclusion raises the possibility that the agency may continue to allow the chemical’s use in cutting oils and commercial penetrating lubricants or impose fewer restrictions on those applications than it may for other uses.
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This week’s findings were part of a final risk evaluation that EPA issued under the Toxic Substances Control Act, which aims to identify chemicals that pose risks to human health or the environment and to impose restrictions that manage those risks.
Perchloroethylene – also referred to as perc or tetrachloroethylene – is currently used in a range of applications that includes dry cleaning chemicals, furniture care products, industrial cleaners and degreasers and adhesives in arts and crafts. After extensive review, EPA said that the chemical can cause neurological problems such as behavioral changes and impaired coordination, as well as irritation of the respiratory system and possibly adverse effects on kidneys and livers.
The agency said these problems can result from short- or long-term exposure to those working with the chemical as well as bystanders. The agency has classified the chemical as likely to cause cancer in humans.
EPA’s evaluation found these risks to be of an unreasonable level in 59 of 61 uses that it evaluated, including manufacturing and use of products containing perchloroethylene. Those included consumer use of aerosol lubricants and degreasers that contain the chemical.
The agency will now develop policies for mitigating those risks and could take steps ranging from prohibiting the manufacture or importation of the chemical to safety procedures in applications that are permitted. By law those policies are developed with public input and must be implemented within two years.
The two uses found not to pose unreasonable risk were distribution of products containing the chemical and use of cutting fluids and penetrating lubricants and greases that contain it. EPA said it evaluated the risk to workers doing eight-hour shifts with cutting machines that use metalworking fluids containing perchloroethylene. The agency said this activity and mist created by the fluid did not create an unreasonable health risk for these workers because the chemical is used in low concentrations and tends to evaporate quickly.
As with many other chemicals, the U.S. already requires dissemination of safety data sheets explaining risks of perchloroethylene and how to mitigate them. Industry is already curtailing the chemical’s use in some applications, such as dry cleaning, where companies are trending toward use of alternative chemicals.