A common industrial chemical used to produce Teflon might pose health risks for young girls and women of childbearing age, an internal report by the Environmental Protection Agency has found.
Agency scientists are concerned because the chemical, ammonium perfluorooctanoate, accumulates in human blood and demonstrates toxic properties. In September, the agency initiated a priority review under the Toxic Substances Control Act, which can be invoked to ban chemicals that pose significant risk of cancer, gene mutations or health defects.
The draft report assesses current scientific work, including studies by various companies.
The chemical, abbreviated in scientific literature as PFOA, is also known as C-8 at the DuPont Company, which manufactures it.
In assessing the risks of the chemical, the draft report used a ratio known as the margin of exposure, under which anything lower than 100 could be cause for serious concern.
In the draft report on C-8, this average ratio ranged from 66 to 80 for women and girls. For men and boys, the averages ranged from 9,000 to 11,000. The gender difference is notable because studies done on human exposure have focused on industrial workers, the vast majority of whom are male.
Studies have also shown that C-8 causes liver damage in rats. Robert Rickard, a DuPont toxicologist, said those studies were not relevant to humans because of the way the chemical worked.
At high dosages, C-8 has also shown development and reproductive harm in rats. DuPont contends that at lower levels they caused no effect. Studies of C-8 exposure on humans have not been conclusive, and the E.P.A. report urged
“We are in full cooperation with the E.P.A. on the study on this product,” said Irvin Lipp, a spokesman for DuPont.
The chemical, which is part of a family known as perfluorochemicals, plays a key role in materials that are widely used in the aerospace, transportation and electronics industries.
A chemical related to C-8, used in the fabric protector Scotchgard, was voluntarily pulled from production by the 3M company in 2000 under pressure from the E.P.A. Since then, 3M has ceased production of perfluorochemicals. DuPont, which had been a longtime customer of 3M’s C-8, began producing it in Fayetteville, N.C., and uses it in a number of factories around the country.
Studies have shown that C-8 accumulates in the blood of workers and in the general population because it takes a long time to break down. The highest levels found among general populations are comparable to the lowest levels found among workers.
It is not known how the general population is exposed to C-8. But DuPont has started a World Wide Web site, c8inform.com, to address concerns about the presence of C-8 in an area’s drinking water. A class-action lawsuit has been filed in West Virginia against DuPont contending that C-8 is harmful to the environment and human health, an accusation the company disputes.
The E.P.A. report, which is dated March 17, is labeled an “internal deliberative draft” and “not subject to” the Freedom of Information Act. The report was first obtained by Inside EPA, a newsletter that monitors federal environmental policy, and was released yesterday by the Environmental Working Group, a group that advocates increased regulation of chemicals.
DuPont said the report was out of date and had not been not peer-reviewed. “It was a leaked document,” Mr. Lipp, the DuPont spokesman, said. “It was stolen.”
E.P.A. officials said they were not ready to make a judgment about the chemicals. “We are concerned enough about it to take it to the next step, because we don’t know enough about the situation,” said Joe Martyak, a spokesman for the agency.