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DuPont Studies Found Three C8 Proxies Toxic

Posted on: Sunday, 1 January 2006, 12:00 CST

By Ken Ward Jr., The Charleston Gazette, W.Va., The Charleston Gazette, W.Va.

Jan. 1--In 1997, DuPont Co. scientists were trying to find possible substitutes for C8, a toxic chemical used to make its signature Teflon nonstick coating and thousands of other popular products.

During separate tests of three materials, DuPont researchers sprayed rats with aerosol versions of the potential C8 alternatives. The tests aimed to determine if the chemicals are toxic when inhaled.

The rats died.

Earlier this month, federal regulators disclosed a few bits of information about the studies.

Among the scant details, U.S. Environmental Protection Agency officials said that the study results showed the three chemicals to be "extremely toxic" to animals.

But the public can't find out what chemicals were involved.

The EPA has not yet made the studies themselves public. DuPont is claiming the chemical identities are trade secrets, and so far The EPA has not overruled the company's position.

EPA officials insist there is nothing to worry about. Based on information provided by DuPont, EPA officials say there is little if any chance for public exposure to these three chemicals.

"My understanding is that these chemicals are never used in a way that will generate an inhalation exposure," said Charles Auer, director of the EPA's Office of Pollution Prevention and Toxics.

Auer said that "some of these materials" were only at the research and development stage and "did not actually enter into commerce."

"There are a number of factors at play that suggest that these chemicals do not suggest any significant risk to the public," Auer said. "They are not used in a way that would create any inhalation exposure."

Auer said the results of the three DuPont studies "increased our confidence in the understanding that we had" about the toxicity of C8 and related chemicals.

"DuPont indicated to us that one of their purposes in running these screens was to determine whether they had materials that might be less toxic than others in the class, so they ran those studies to see whether they would fall into that less-toxic category," Auer said.

Instead, DuPont found that, "They behave like other toxic members of the category," Auer said.

DuPont officials did not respond to a request for an interview about the three studies.

The EPA has known about the three chemicals and the test results for at least a year.

The studies were among the documents in more than 40 boxes of C8-related information that DuPont provided to the the EPA in December 2004 and January 2005. DuPont gave the EPA the records only after the agency filed a civil complaint that alleged DuPont officials covered up key evidence of C8's health dangers.

On Dec. 14, the EPA agreed to settle its complaint against DuPont. The company would pay $10.25 million in fines and spend $6.25 million on certain C8 studies and a public school environmental safety program.

The $16.5 million in total payout by DuPont was a fraction of the more than $300 million in fines the company could have faced.

EPA officials said the penalty "sends a strong message that companies are responsible for promptly informing the EPA about risk information associated with their chemicals."

DuPont admitted no wrongdoing, and continues to maintain that "no human health effects are known to be caused" by C8.

Under the federal Toxic Substances Control Act, or TSCA, companies are required to timely report to the EPA certain kinds of evidence that chemicals they make or use cause adverse health effects.

In its July 2004 complaint, the EPA alleged that DuPont for 20 years covered up key data about C8's health effects and about the pollution of water supplies near the Washington Works plant.

Specifically, the EPA alleged that DuPont never told the government that it had water tests that showed C8 in residential supplies in concentrations greater than the company's internal limit.

Also, the EPA alleged that DuPont withheld for more than 20 years the results of a test that showed that at least one pregnant worker from the Parkersburg plant had transferred the chemical from her body to her fetus.

C8 is another name for ammonium perfluorooctanoate, or PFOA. It is part of a family of chemicals called fluoropolymers. DuPont has used it since the 1950s at its Washington Works plant south of Parkersburg to make Teflon and other similar nonstick and stain-resistant products that are widely used.

Researchers are finding that people around the world have C8 in their blood. The blood levels may be generally very small, but it is unclear whether these amounts are dangerous.

Nonstick cookware may be one route of exposure to C8, but recent studies suggest that food packaging may be a much bigger source.

In settling its civil complaint against DuPont, the EPA threw in four new counts that had never before been disclosed by the agency.

The first concerned DuPont's failure to immediately report results of a study that found troublesome levels of C8 in the blood of non-plant workers who live near the Washington Works facility.

Each of the other three concerned DuPont's alleged failure to report studies concerning other, C8-like substances.

All four counts were settled for a total of $250,000, according to the formal settlement documents, filed with the EPA's Environmental Appeals Board.

In the settlement documents, the EPA described each of the three chemicals as "a perfluorinated chemical substance, the identify of which has been claimed as TSCA Confidential Business Information by DuPont."

All three chemicals were tested in 1997, but the results not reported to the EPA until late 2004 or early 2005.

In January 2002, DuPont did report the results of a separate test on one of the three materials to the EPA, according to the settlement document.

A one-page summary of that study is contained in public records concerning the EPA's larger review of C8.

The summary identifies that material as a mixture of water, isopropyl alcohol and three fluorinated compounds.

The three are: Poly(difluoromethylene), alpha-fluoro-omega[2-(phosphonooxy)ethyl]-, monoammonium salt; Poly(difluoromethylene), alpha-omega-[2-(phosphonooxy)ethyl]-, diammonium salt; and Poly(difluoromethylene0, alpha,alpha-[phosphinicobis(oxy-2,1-ethanediyl)]bis[omega-fluoro-], ammonium salt.

The study summary says that all of the rats exposed to 120 milligrams per cubic meter of the material and half of the rats exposed to 57 milligrams per cubic meter died within one day of their exposure.

All of the rats exposed to 23 milligrams per cubic meter survived that smaller amount, the study summary says.

The EPA's Auer said the 1997 study of this material that DuPont did not disclose until much later exposed rats to 400 milligrams per cubic meter of the material.

In that study, "All of the test animals died," Auer said.

To contact staff writer Ken Ward Jr., use e-mail or call 348-1702.

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Copyright (c) 2006, The Charleston Gazette, W.Va.

Distributed by Knight Ridder/Tribune Business News.

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Source: The Charleston Gazette

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