WASHINGTON — When the U.S. Environmental Protection Agency (EPA) posted the final health assessment for tetrachloroethylene—also known as perchloroethylene, or perc—to its Integrated Risk Information System (IRIS) database in February, it deemed the chemical to be a “likely human carcinogen.”
The assessment replaces the 1988 IRIS assessment for perc and for the first time includes a hazard characterization for cancer effects. The assessment underwent several levels of rigorous, independent peer review including: agency review, interagency review, public comment, and external peer review by the National Research Council, according to the EPA, and all major review comments were addressed.
The Halogenated Solvents Industry Alliance says 70% of U.S. commercial dry cleaners use perc; EPA estimates the total number to be 27,000. So what does this development mean for the future of the industry’s preferred solvent?
Paul Anastas, assistant administrator for EPA’s Office of Research and Development, says the new assessment provides “valuable information to help protect people and communities from exposure to perc in soil, water and air. This assessment emphasizes the value of the IRIS database in providing strong science to support government officials as they make decisions to protect the health of the American people.”
The Halogenated Solvents Industry Alliance (HSIA), whose member companies manufacture and market perc, welcomes the completion of the IRIS process and says it is pleased that EPA completed the review, removed some uncertainties related to evaluating human health exposures to the solvent, and reassured consumers that wearing clothes drycleaned with perc is not a health concern.
“EPA took into account the strong comments it received from the National Research Council during its 2008 review of the document. However, the Agency’s report reveals inconsistencies with the approach used to assess the cancer risks from trichloroethylene,” says John Bell, HSIA director of Scientific Programs.
He also notes that “while EPA has indicated it is considering a new Maximum Contaminant Level as low as 0.05 parts per billion (ppb), this IRIS review establishes a negligible human health risk at 20 ppb or higher.”
Perc is one of the most-studied industrial chemicals, HSIA says, and has been used safely by industry for more than 50 years
It has been comprehensively regulated under the Safe Drinking Water Act, the Resource Conservation and Recovery Act, and the Clean Air Act for more than 20 years. These regulations adequately restrict its use and emissions and require proper handling and disposal, HSIA says. Perc is fully recyclable and represents no harm to the environment or risks to human health when used and handled appropriately, the Alliance continues.
Environmental advocates, such as the nonprofit Environmental Working Group, praised the ruling.
“The evidence against this ubiquitous drycleaning chemical piled up for years, like dirty laundry in the corner of the room,” says David Andrews, Ph.D., a senior scientist. “It’s encouraging that EPA is completing this assessment so that health measures can be taken to protect workers and the public.”
The Environmental Working Group went so far as to urge consumers to take their dry cleaning to businesses that do not use perc. It claims the substance can remain on clothes and evaporate into the air at home, unnecessarily exposing the residents.
In light of the EPA’s updated assessment, 71.6% of respondents to March’s AmericanDrycleaner.com Wiresurvey believe the solvent will no longer be a viable option for the average operator within 10 years. Of that group, 37.5% believe perc has another 10 years while 34.1% say it’s only five years. Approximately 13% give perc another 20 years, while equal shares of 8% peg its time remaining as a viable solvent option as either 15 years or “indefinitely.”
Among respondents to the unscientific Wire survey, 69.9% say they use perc. Other solvents used by respondents include high-flashpoint hydrocarbon, GreenEarth (D5 silicone), liquid CO2, Solvair, and DrySolv (n-Propyl Bromide).
Cleaners also utilize “other” solvents not on the list provided within the survey, including SolvonK4, low-flashpoint hydrocarbon and water (wet cleaning).
The survey asked respondents for their reaction to the news. As one might expect, those who use perc generally reacted unfavorably:
• “With today’s closed-loop technology, I don’t see how it’s possible that perc is even considered to be a carcinogen. They need to quit subjecting animals to perc and do test studies with cleaners who clean clothes day in and day out. I am a third-generation dry cleaner with a business that’s 101 years old, for what it’s worth.”
• “One need only handle the product in a safe manner, just like anything else of this nature... An outright ban would be overkill.”
• “What is the reasoning for the concern? It’s cancer causing but OK to use? Is that like driving a car without brakes?”
• “Very distressing. We don’t need any more negative press.”
• “Much ado about nothing. Just another typical government solution to raise the costs without accomplishing anything.”
• “Perc is dead meat now.”
• “I have not seen the statistical evidence that makes perc a likely human carcinogen.”
• “They are the most disruptive group in the business world. Most that work at EPA don’t have a clue about all the past studies relating to the use of perc as a drycleaning agent. They don’t understand that the new equipment available today is efficient and will contain any possible spills.”
• “Not surprised about the likely classification. Surprised that they didn't go ahead and say they suspect wearing the (drycleaned) clothes to be hazardous.”
• “Probably scientifically accurate, but likely to be taken out of context by an unscientific public.”
• “The same as my customers: none.”
Regardless of your position on perc, it appears likely that the EPA will have more news regarding its use and handling in the years to come.