The Environmental Protection Agency is taking a cautious approach to a scientific panel’s conclusion that a chemical used by DuPont Co. to make the nonstick substance Teflon is a likely human carcinogen.
The EPA stated earlier this year that its draft risk assessment of perfluorooctanoic acid and its salts found “suggestive evidence” of potential human carcinogenicity, based on animal studies.
In a draft report released Monday, the majority of members on an EPA scientific advisory board that reviewed the agency’s report concluded that PFOA, also known as C-8, is “likely” to be carcinogenic to humans, and that the EPA should conduct cancer risk assessments for a variety of tumors found in mice and rats.
Neither the EPA nor the advisory board attempted to quantify any cancer risks from the chemical, but the board suggested that EPA should conduct risk assessments for a variety of PFOA-induced tumors found in laboratory animals.
“It is not yet known whether carcinogenicity will represent the most sensitive endpoint for PFOAs,” the board added, suggesting that the chemical may also affect development and poses a potential threat to the nervous and immune systems.
EPA spokesman Rich Hood said Wednesday that the board’s draft report is an “important step” in determining whether PFOA is dangerous enough to regulate, but he was unwilling to say whether it increases the likelihood of regulation.
“I think there are a lot of questions that need to be more definitively answered before we can say what the agency’s final action is going to be,” Hood said. “It’s not a good thing to jump to unwarranted conclusions.”
Environmentalists nevertheless hailed the report, which will be discussed by EPA officials and SAB members in a public teleconference July 6, saying it will increase pressure on the EPA to conduct human health risk assessments for liver, breast, pancreatic and testicular cancer, as well as potentially toxic effects on the immune system.
“This makes it hard for the EPA not to move forward aggressively,” said Richard Wiles, senior vice president for the Environmental Working Group, an advocacy and research organization.
While PFOA is used to make Teflon, it is not present in Teflon itself, which is applied to cookware, clothing, car parts and flooring. PFOA also is used to produce materials used in firefighting foam, phone cables and computer chips.
DuPont officials would not comment on the report but said in a statement that human health and toxicology studies suggest that PFOA exposure does not cause cancer in humans and does not pose a health risk to the general public.
“To date, no human health effects are known to be caused by PFOA even in workers who have significantly higher exposure levels than the general population,” the company said.
DuPont also said data from its employee health studies and those conducted by 3M Co., which stopped manufacturing PFOA in 2000, “deserve greater consideration in the EPA’s final risk assessment rather than relying solely on animal testing models.”
DuPont’s studies, which are still ongoing, have found elevated levels of total cholesterol and fats called triglycerides among workers exposed to PFOA, but no indication that PFOA was the cause of increased serum cholesterol and triglycerides.