The United States Environmental Protection Agency released a draft assessment on January 12 stating that there is some evidence that perfluorooctanioic acid (PFOA) -- a chemical used by US chemical giant DuPont to make Teflon nonstick cookware and other coatings -- is carcinogenic.

DuPont has about 20 wholly owned or joint venture operations in China. It produces coatings for nonstick cookware at its Shenzhen plant and automotive coatings at its Beijing and Changchun plants. The State Environmental Protection Administration does not so far have any comment on its US counterpart's findings.

Studies have linked PFOA to liver and testicular cancer in rats, as well as to developmental defects and immunosuppression. In the EPA's tests, the substance also showed up in the breast milk of rats.

The EPA found that the chemical could raise levels of cholesterol and fats called triglycerides in the human body, which can increase the likelihood of a heart attack or stroke. A DuPont study of workers exposed to the chemical arrived at the same findings, although the company holds that the levels of PFOA to which the general public is exposed pose no health risk.

While it is not warning consumers against using products made with PFOA, the EPA says on its website that it is asking an outside panel of experts to assess the risks further to "ensure the most rigorous science is used in the agency's ongoing evaluation of PFOA."

DuPont responded that it recognizes that the presence of PFOA in human blood raises questions that should be addressed. However, company spokesman R. Clifton Webb said, "DuPont remains confident that based on over 50 years of use and experience with PFOA there is no evidence to indicate that it harms human health or the environment."

Researchers have found that although rats eliminate PFOA from their bodies within days, the chemical accumulates in human blood and can remain there for four years or more. In the early 1980s, DuPont's studies showed that an employee had passed the chemical on to her fetus.

PFOA is known to leach into soil and water, as water supplies near US plants have been contaminated with high levels of the chemical. However, it has also been found in areas and in animals far from such plants, and scientists are not sure how it travels.

Since the chemical is a processing aid, it is not expected to appear in finished products. However, it is used to make hundreds of industrial and consumer products, including soil- and water-resistant coatings on textiles and carpets; as well as in the automotive, mechanical, aerospace, chemical, electrical, medical and construction industries; and in nonstick coatings on cookware.

Some researchers believe that as Teflon products age, they release chemicals that break down into PFOA. DuPont says that extensive testing shows this not to be the case.

In October last year, the newly established Chinese Academy of Inspection and Quarantine sampled 28 different Teflon-coated pans from 18 manufacturers -- about 90 percent of those sold in the domestic market -- and found they showed no traces of PFOA.

In September 2004, DuPont and residents of an area near a US Teflon-making plant reached a preliminary out-of-court settlement concerning complaints that PFOA contaminated private wells and water sources in West Virginia and Ohio. DuPont has agreed to pay as much as US$343 million to settle those claims.

In a separate investigation, the US EPA is alleging that for decades DuPont withheld information concerning the potential risk PFOA poses to human health and the environment. At an EPA administrative court hearing last month, DuPont aggressively contested the allegation, saying that it had no obligation to provide the information. If it is found to have acted wrongfully, DuPont may be ordered to pay fines of up to US$300 million.

(China.org.cn January 20, 2005)