DuPont's troubled chemical
C-8 is widespread in the environment. How did it get there, and should we be worried?
By FRED BIDDLE and JENNIFER GOLDBLATT
A little-known manmade chemical is found in the tissue of living things around the globe.
It is in the flesh of dolphins and cormorants off the Italian coast.
It is in 5 percent of the bread, green beans and ground beef sampled in supermarkets in southern states.
It is in the blood of up to 96 percent of people in the United States, a study suggests.
The chemical is known as C-8.
C-8 is used to make the DuPont Co.'s Teflon that coats cookware. It is also released in the decomposition of fluorinated telomers, a chemical used to make some fast-food wrappers resistant to grease. Teflon and telomers are part of a family of fluorinated compounds pioneered and dominated by DuPont.
Scientists know of no other sources of C-8.
The U.S. Environmental Protection Agency wants to know how C-8 enters the environment and whether it's harmful. Recent evidence that C-8 exists in the blood of most people led the agency to question whether the public health was adequately protected.
Much remains to be discovered about how C-8 gets into humans and whether it is harmful.
The News Journal interviewed dozens of experts and reviewed more than 100 scientific papers to understand what is known about the source and the health effects of C-8, also known as PFOA, the initials of its chemical name, Perfluorooctanoic Acid.
DuPont has said it does not know why the chemical has become so pervasive, acknowledging C-8 has been found in the blood of the general population at a level five times the maximum the company strives to achieve in the air and water around its factories where C-8 is made or used. DuPont said, however, the C-8 levels pose no threat.
"In more than 50 years of use by DuPont and others, there have been no known adverse human health effects associated with PFOA," Dr. Uma Chowdhry, DuPont's global vice president for central research and development, testified to the EPA in June.
The chemical causes cancer and birth defects in lab rats. But DuPont and others that have made or used C-8 say it is harmless to people. That assurance is based on decades of C-8 use with no evidence of ill effects, they said.
The EPA is conducting hearings that could lead to regulating or banning the chemical. The agency could decide to leave the chemical unregulated.
The EPA hearings are being monitored by the Food and Drug Administration. The FDA said it will use the findings to decide whether to reconsider its decades-old approvals of Teflon on nonstick pans and telomers in food packaging.
The Consumer Product Safety Commission also is attending the EPA hearings to determine whether it should require warning labels or some other regulation for Teflon-coated cookware. And the U.S. Centers for Disease Control and Prevention recently has proposed adding C-8 to the list of chemicals for which it routinely screens blood.
C-8 has been made in only three locations in the United States over the past half century. Because C-8 must come from a manmade source, the EPA plans to trace C-8 from the time it is manufactured until after the products with coatings linked to the chemical are thrown away. Agency officials have stressed that the inquiry is in its early stages.
"It's premature and inappropriate to advise people to avoid these products," said Charles Auer, director of the EPA's Office of Pollution Prevention and Toxics.
Discovered by DuPont
The EPA's investigations focus on a family of chemicals that made DuPont a household name. They played a key role in developing the atomic bomb and modern refrigeration.
DuPont's foray into this fluoropolymer chemistry began in 1938, with Roy Plunkett's accidental discovery of polytetrafluoroethylene, the chemical DuPont now sells as Teflon. That chemical eventually spawned a $2 billion industry in the United States, where manufacturers include Asahi Glass Fluoropolymers USA, Daikin America Inc. and Dyneon LLC.
What makes these products so strong is fluorine, which forms tight chemical bonds with carbon in long molecular chains. C-8 is added to the compounds to ensure that the chains will align properly and that the finished coatings will have a slippery, nonstick quality.
The difficulty of working with fluoropolymers and concerns about polymer fume fever made DuPont wary about commercializing Teflon for more than a decade after Plunkett's discovery. The company didn't apply for FDA approval to use Teflon on cookware until 1959.
DuPont continued to advance the chemistry in the 1960s when it developed fluorinated telomers, which provide Teflon-like protection against dirt and grease for textiles, carpets and papers. Fluorinated telomers are also based on a chain of fluorine and carbon bonds.
Telomers have shorter molecular chains than Teflon, and that makes them more applicable for objects like textiles, carpets and papers, where it is important to retain the object's original appearance.
In 1967, the FDA approved Zonyl, DuPont's leading brand of fluorinated telomers, for use in food packaging. It was a less costly and less labor-intensive alternative to the waxed-based papers previously used, which could not be recycled.
Telomers are even marketed under the Teflon brand in such applications as the "Stain Defender" used on clothing. Fluorinated telomers also are used in DuPont's own Stainmaster carpet brand and some fast-food packaging.
DuPont executives said that they don't know all the products coated with fluorinated telomers because DuPont sells to intermediaries such as paper companies, not end users such as fast-food companies. The intermediaries add DuPont coatings to their food cartons, wrappers and other products.
Telomers pose mystery
EPA officials have said they think Teflon and fluorinated telomers could be a source of C-8 in the environment.
DuPont disagrees. The company said it extracts all detectable C-8 from Teflon during production and that its researchers have been unable to detect the chemical in nonstick cookware.
DuPont said Teflon coatings cannot break down into C-8. The company also said its studies have shown that hot foods in telomer-coated packaging could not cause the release of C-8.
C-8 is not used to make fluorinated telomers. Recent scientific findings show they break down into C-8, however. Scientists, including DuPont's, are baffled about how that occurs.
"If you're asking me: Is that transformation possible? I guess the answer to that question would be yes, it's possible," said Robert Ritchie, a DuPont director of planning and technology. Company scientists also said they don't know what chemical reactions occur to telomer-coated products as they are used and thrown away, one focus of the EPA's inquiry.
Ritchie said that any C-8 release would be "very, very small" because of the small amount of fluorinated telomers used to coat any item. "If we had any reason to believe that was a safety issue for fluorinated telomers-based products, we wouldn't have commercialized them," Ritchie said.
DuPont began studying whether telomers can emit C-8 in 1999.
"Telomers would not cause health effects under normal uses," said R. Clifton Webb, a spokesman for DuPont. "Under normal uses, telomers are added in such small amounts to finished consumer products that it is not probable for a consumer to ingest or absorb these materials in the body at a dose that would cause a health concern."
Cookware may be source
Although fluorinated telomers are a central focus for the EPA, the agency also has questioned whether nonstick cookware, which account for about 65 percent of cookware sold in the United States, are giving off C-8 when they are heated. Industry analysts said DuPont dominates the nonstick cookware coating market, although DuPont won't disclose its share.
A study published in the British science journal Nature two years ago concluded that C-8 was one of several toxic gases emitted by Teflon heated to 680 Fahrenheit and 932 F. Normal cooking temperatures can reach 536 degrees.
DuPont called the Nature study misleading.
"Any material, if heated to a high enough temperature, will decompose," the company said in a news release following the release of the Nature study. Even when Teflon decomposes, DuPont said its own research shows that Teflon does not release C-8.
The University of Toronto researchers who conducted the Nature study defended their work and said they expect to publish another study of Teflon. Their recent research, which found several previously unknown fluorinated compounds, underscores how little is understood about the decomposition of Teflon, said Scott Mabury, one of the researchers and chairman of the university's chemistry department.
Regulators also want to know whether there are other Teflon coated products that could be a source of C-8 in the environment.
The EPA plans to test Teflon pans and other Teflon-coated products, such as shatter-resistant light bulbs and sealants used in military machinery. The EPA also has ordered tests to determine whether products coated with fluorinated telomers release C-8. The agency said it wants to gauge the potential for C-8 to be released at every stage of a product life cycle.
C-8 entered water supply
The inquiry the EPA is conducting began as a groundwater pollution issue in the Ohio River Valley. One source of C-8 contamination that no one disputes is the Teflon manufacturing process.
DuPont has made Teflon at a plant near Parkersburg, W.Va., for more than 50 years. For most of that time, it has released C-8 into the adjacent Ohio River, the air and local landfills.
In the late 1990s, the EPA joined Ohio and West Virginia environmental regulators in an investigation of the resulting groundwater pollution around the plant. The investigation found C-8 in the groundwater. As a result, DuPont agreed to replace the drinking water of tens of thousands of area residents should C-8 levels reach an agreed-upon level, which has not happened.
DuPont has separately pledged to reduce direct C-8 pollution 50 percent from 1999 levels nationwide by 2006. The voluntary pledge has now been incorporated into a consent decree between DuPont and the EPA.
DuPont's unregulated emissions into the air and water from its Parkersburg plant totaled about 20,000 pounds last year. In 1999, the most recent year for which it provided records, the company also released nearly 10,000 pounds of C-8 waste into the Delaware River. The waste was sent from Parkersburg for treatment at the company's Chambers Works plant in Deepwater, N.J.
The EPA's concern over the groundwater contamination grew largely because of animal and human studies conducted since the 1970s. Those studies found that C-8 causes cancerous tumors in the pancreas, liver, mammary glands and testicles of lab rats, as well as developmental problems.
DuPont said that although C-8 can cause tumors in rats, those results do not mean it causes cancer in people.
3M stops producing C-8
Much of the research on how pervasive C-8 is in the environment and how it got there was conducted by the 3M Co., which formerly supplied DuPont with C-8.
After decades of research, 3M announced in 2000 that it would stop selling C-8, although the company continued to produce a small amount for its own use. 3M cited environmental concerns in its decision, including the fact that the chemical is found in the blood of so many people. The company said, however, it doesn't believe C-8 poses a risk to humans.
Since the mid-1970s, studies of blood donors and children participating in clinical trials, conducted mostly by 3M, have found C-8 in the vast majority of blood samples of people across the country. The most recent 3M study showed C-8 in the blood of 96 percent of 528 children tested from 23 states and Washington, D.C.
3M has turned over the results of its studies to the EPA. The EPA said it expanded its examination of C-8 in part because of 3M's blood studies.
EPA officials said 3M's decision to stop making C-8 for sale heightened the agency's interest in the chemical.
"We were surprised but pleased the day 3M walked into a meeting with senior EPA officials and said, 'We've decided to stop making perfluorooctyl chemicals, including PFOS and PFOA, not only here in the U.S. but also worldwide,'" the EPA's Auer said. "How often do you see a company respond in such a forthright manner, especially given the economic and brand name importance of this line of chemistry to 3M?"
As early as 1981, a 3M study published in the journal Analytical Biochemistry found that lab rats fed fluorinated telomers metabolized them into C-8. A 3M test completed a year ago, after 3M had withdrawn from the business, showed that microorganisms in wastewater sludge broke down fluorinated telomers into C-8.
Following those studies, 3M withdrew entirely from selling the C-8 that feeds the nonstick market. DuPont, which was not a manufacturer of C-8, needed a supplier for the chemical necessary to make Teflon. It began making C-8 in October 2002 at a plant in Fayetteville, N.C.
C-8's effect on humans
In addition to the finding that C-8 is widespread, scientific studies have also found that C-8 doesn't break down in the environment and diminishes slowly in the body.
A study 3M released last year of retirees who had worked near C-8 at one of the company's plants concluded that it takes 4.4 years for the human body to flush out one-half of the chemical it is exposed to at any given moment.
DuPont acknowledges that C-8 is persistent in the environment, but says that should not be a human health concern.
"Presence of a substance alone does not support the conclusion that the substance caused or likely caused an adverse human health effect," DuPont wrote in a June letter to the EPA.
At the urging of the EPA earlier this year, DuPont and the fluoropolymer industry agreed to conduct additional research to address the agency's questions. DuPont has joined with the other makers of fluorinated telomers to learn more about the chemicals.
The EPA is also gathering information on the temperatures reached in trash incinerators because of the potential for C-8 air pollution from burned Teflon and fluorinated telomer-coated products.
FDA officials have said they will consider the EPA's findings before deciding whether to reconsider the agency's 40-year-old approval of Teflon for use in nonstick cookware.
"If any information is forthcoming which indicates that a food-related product is unsafe, the agency will take the appropriate action," said Dr. Mitchell Cheeseman, director of the division of food contact notifications.
DuPont promotes Teflon
DuPont said it is confident Teflon and fluorinated telomers will survive the scrutiny.
Teflon and related products are part of businesses that collectively make up less than 5 percent of DuPont's annual sales, which totaled $24.1 billion last year. DuPont will not release sales or profit margins for its fluoropolymer business.
But Teflon is an important product to DuPont. The company has chosen fluoropolymer compounds as the focus for the biggest image makeover in years. Teflon fabric protector, nonstick coatings and Stainmaster carpet brands lead a television and print ad campaign aimed at working mothers that DuPont unveiled in July.
DuPont officials said they are confident that C-8 is safe.