Auer said the draft report, based on animal studies, would be sent to a science advisory board for helping determining the risks.

DuPont and EPA have been sparring over PFOA, used to make many of the company's most popular products, which range from auto fuel systems, firefighting foam and phone cables to computer chips, cookware and clothing.

The agency said in a statement it "has concerns with respect to the potential nationwide presence of PFOA in blood and with the potential for developmental and other effects suggested by animal studies." But it also said there are "significant uncertainties in the agency's quantitative assessment of the risks of PFOA."

Chemical maker DuPont Co., which is based in Wilmington, Del., and produces the chemical at a plant in Fayetteville, N.C., said Wednesday it welcomed EPA's report and was trying to minimize people's exposure to the chemical.

"Although, to date, no human health effects are known to be caused by PFOA, the company recognizes that the presence of PFOA in human blood raises questions that should be addressed," DuPont officials said in a statement.

Initial research by EPA suggests that PFOA could be carcinogenic in rats — but the cancer hazard for people is less certain. It also indicates the chemical targets the liver and is present in the breast milk of rats.

The Environmental Working Group, an advocacy organization that brought DuPont's record on PFOA to EPA's attention, said it believes EPA ignored its own scientific advice on defining the cancer-causing potential of the chemical to benefit DuPont.

"At every turn in this important process, EPA officials favored DuPont," said Ken Cook, EWG's president.

DuPont said its own study, based on 62 blood and urine tests among 1,000 employees at its Washington Works plant in Parkersburg, W.Va., showed "no human health effects known to be caused" by PFOA. It showed elevated levels of total cholesterol and fats called triglycerides among workers exposed to PFOA, but noted that the study data "did not indicate that PFOA was or was not the cause of the increases in serum cholesterol and triglycerides."

Sol Max, DuPont's chief medical officer, said "no association would be seen in the general public" for cholesterol and triglycerides, because exposure to the chemical was minimal outside a work setting.

In September, DuPont and residents around the Ohio Valley Teflon-making plant entered into a proposed legal settlement to resolve complaints that PFOA contaminated private wells and water sources in West Virginia and Ohio. DuPont has agreed to pay as much as $343 million to settle those claims.

At an EPA administrative court hearing last month, DuPont battled charges by EPA that it did not fulfill its obligation to release PFOA information to EPA. DuPont said it did and maintained that PFOA was harmless.

--------------------------------------------------------------------------------