EPA issued a draft assessment of the potential risks of perfluorooctanoic acid and its salts, known as PFOA, or C-8. The report, based on animal studies, says some evidence exists that PFOA is carcinogenic in rats, but the cancer hazard for people is less certain.

It suggests the chemical targets the liver and is present in the breast milk of rats. It also says the chemical could raise cholesterol and triglyceride levels in people — a finding that chemical maker DuPont Co. publicly released this week. DuPont said its study found no overall health problems.

PFOA is used to make Teflon, but it's 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.

The Environmental Working Group, an advocacy organization that brought DuPont's record on PFOA to EPA's attention, said that based on other studies of PFOA, it believes the potential cancer and heart disease risks from the chemical are being played down too much.

DuPont's study was released to the EPA and to its workers, who were exposed to PFOA at its plant in Parkersburg, W.Va. The company's study was reviewed by experts from five universities, and DuPont plans more follow-up research.

In its study, the Wilmington, Del.-based company reported there were "no human health effects known to be caused" by PFOA.

The company is battling charges by EPA that it did not fulfill its legal obligations to share lab results about the potential harm from the unregulated chemical, known as PFOA or C-8, on several occasions. An administrative court hearing on those charges was held last month.

DuPont agreed, though, to pay as much as $343 million to settle charges it contaminated drinking water in West Virginia and Ohio with PFOA over the past 50 years. As many as 60,000 residents around the plant sued over their exposure to the chemical.