TOXIC SHOCK: PART TWO

Coming to terms with perils of non-stick products

MARTIN MITTELSTAEDT
ENVIRONMENT REPORTER
The Globe and Mail - Saturday, May 27, 2006

Teflon and Scotchgard are among the best-known brand names in the world, and have been used in billions of dollars of non-stick and stain-resistant consumer products.

Their use is so widespread, there probably isn't a person in North America who hasn't eaten a meal cooked on a non-stick pan, worn stain-resistant or water-repellant clothing, or had fast food served on a greaseproof wrapper.

But after nearly five decades of extensive consumer and industrial use, some of the chemicals behind the popular brand names have been linked to cancers and even deaths in laboratory animals, and Environment Canada is concerned about their impact on wildlife.

Some environmental groups are comparing the chemicals to DDT, the pesticide that was the poster child for the environmental movement during the 1960s before it was banned. But while DDT eventually breaks down into less-harmful substances, these new chemicals don't appear to degrade under any known biological process.

"A good way to think about it is as the DDT of this millennium," said Richard Wiles, vice-president of Environmental Working Group, a Washington-based environmental organization that was one of the first to question the safety of the chemicals. "The fact that they last forever really raises the stakes. Even DDT goes away after decades or centuries."

DuPont Co. said its Teflon frying pans and other kitchenware are safe if used properly.

Health Canada says human exposures to the chemicals aren't high enough to be a concern.

"When you're using the cookware as it's intended to be used, at the temperatures it's intended to be used, it's perfectly safe," said David Boothe, DuPont's global manager for such products as Teflon.

The chemicals are part of a broad family of substances known as perfluorochemicals, which use the elements fluorine and carbon to make non-stick and stain-resistant coatings. Perfluorochemicals have a molecular structure that prevents them from mixing well with water or oil, which is why they are so useful in making such consumer items as French fry wrappers that stop grease and raincoats that shed water.

Scientists in the United States have zeroed in on two members of this chemical family as particularly worrisome: perfluorooctanoic acid, or PFOA for short, and perfluorooctanyl sulfonate, or PFOS. They have been used to make some of the world's most-famous brand names, including Teflon and Scotchgard.

Environment Canada has concluded that PFOS levels have reached such high levels in animals like polar bears, which have been found to have more than 4,000 parts per billion in their livers, that they "could be harmed by current exposures."

Environmentalists say Health Canada did not use the same conservative safety protocol that Environment Canada applied to animals. Using Environment Canada's approach to polar bears, adults and children in Canada would have been deemed to have had excessive exposures and would need to have lower levels to be certain that no health problems are occurring.

Some environmentalists contend that the differing approaches have caused a situation in which chemical safety calculations for wildlife are far more rigorous than those for humans.

"The assessments are more protective of polar bears than human children," said Rich Smith, executive director of Environmental Defence, a Toronto activist organization.

In an ironic turn for chemicals that are used to make non-stick products, both PFOS and PFOA have been found to have an extreme affinity to stick to living things and, once absorbed, are incredibly hard to shed, often taking decades to be excreted.

"We've never seen them degrade under any relevant environmental conditions," said Scott Mabury, a chemistry professor at the University of Toronto. "I often say they redefine persistence as we know it."

The chemicals are found in nearly all North Americans and in almost every wildlife species scientists have tested. Health Canada scientists checking PFOS levels in humans found them in every one of 56 Canadian volunteers tested, according to a paper published in 2004.

Because the chemicals aren't made in Canada, the widespread human exposure suggests that small amounts of PFOS are breaking off of consumer goods and being absorbed by people and animals, although scientists don't know exactly how this is occurring.

The first public inkling that the chemicals might pose a danger emerged in May of 2000, when 3M unexpectedly announced that after 40 years of production, it was phasing out PFOS, used in Scotchgard, its well-known stain and water repellant. The company also said it would stop making PFOA, which has a similar chemical structure and is also used to make non-stick, stain-resistant coatings.

In explaining the action, 3M said it was because PFOS was starting to be found in the environment at low levels. Nonetheless, it said its products were safe and that "all existing scientific knowledge" indicated exposure at the levels being detected wasn't an environmental or human health hazard.

Mr. Wiles's group began studying perfluorochemicals after 3M's announcement.

"It just seemed to us not plausible that a company would drop its signature product or chemical, if there weren't a really big problem right in plain sight," Mr. Wiles said.

The same day 3M made its announcement, the U.S. Environmental Protection Agency quietly notified Environment Canada and other governments around the world that the company acted because PFOS "appears to combine persistence, bioaccumulation and toxicity properties to an extraordinary degree."

Bioaccumulation is the tendency for harmful chemicals to become more concentrated in living things higher up on the food chain.

The EPA notice was based in part on laboratory tests, conducted for 3M, that indicated the chemical killed some rat pups born to mothers that were themselves exposed in utero. The EPA noted that "it is very unusual to see such second-generation effects," which suggest that exposures are more dangerous during fetal development than they are to adults.

The effects had been generated by relatively small daily doses -- about half a part per million, or the equivalent of a half kernel of corn in about 10 bushel baskets filled with the grain.

In January, the EPA announced an agreement with DuPont Co. and seven other companies to cut PFOA emissions from their plants and products by 95 per cent by 2010, and work toward complete elimination by 2015.

Shortly after this announcement, an EPA panel determined that PFOA was a likely human carcinogen, although earlier testing had found that it also had multiple-generation effects in rats, with pups of exposed mothers being "found dead or presumed cannibalized," according to one study sponsored by 3M.

This study is part of a growing body of research conducted by scientists around the world. Eleven studies have shown that PFOA or related chemicals damage the thyroid gland. Another five studies have shown that PFOA alters male reproductive hormones. Animal tests have also linked it to breast, testicular, liver and pancreatic cancers or tumours.

Among its many uses, PFOA is a processing aid involved in making Teflon, although DuPont has taken pains to publicize to consumers that pots and pans coated with its well-known product don't contain the chemical.

However, DuPont faces a class-action lawsuit, filed in U.S. Federal Court in Des Moines, Iowa, alleging that Teflon cookware releases PFOA and other harmful chemicals if heated to high temperatures. Pans would have to be left on an element at high heat for about four or five minutes to reach 680 degrees F, the temperatures cited for adverse effects in the lawsuit. That's about three times higher than the temperature at which water boils and is a level at which food would be charred.

For environmentalists, the corporate efforts to phase out PFOA and the ending of PFOS production are viewed as a sign of the dangers the chemicals posed.

"It is hugely significant that industry agreed to do this," Mr. Wiles said. "They don't agree to do things like this . . . unless they recognized there was a huge environmental and public health problem with these chemicals."

Environment Canada hasn't taken action against PFOS because 3M has agreed to drop the chemical, although it has placed a temporary import prohibition on four newly developed varieties of stain-resistant coatings, known as fluorotelomers, that it feared could break down into PFOA and related compounds.

The government also plans to impose reductions on PFOA along the lines of the EPA agreement, with an announcement expected as early as next month.

Citing commercial confidentiality, Environment Canada would not identify the companies whose chemicals have been banned from entering the country, other than to say they are among the eight manufacturers covered by the EPA's agreement on PFOA. DuPont makes two of the fluorotelomers, which are available for use in the United States.

Canadian regulators didn't catch PFOS and PFOA as possible hazards because they were grandfathered from in-depth safety assessments when the country adopted comprehensive pollution legislation in 1988. The law exempted chemicals then in use from detailed safety reviews, although it placed more scrutiny on new substances. The chemicals escaped scrutiny in the United States because of similar regulatory gaps.

"These chemicals were missed," said Derek Muir, an Environment Canada research scientist. "That was a mistake."

Canada is trying to close this regulatory loophole under a requirement that all 23,000 grandfathered chemicals be given at least a preliminary evaluation to see whether they need further study, although this process won't be completed until later this year.

The widespread release of the perfluorochemicals wasn't detected in the 1970s when DDT, PCBs and other contaminants were banned because the sophisticated scientific equipment needed to find them in the environment wasn't widely available until the mid-1990s. Since at least 1979, 3M had known that PFOS was in the tissues of production workers, but this wasn't widely known outside of the corporation.

Although average levels of the contaminants in most people are still low, part of the population has been found to have exposures that are many times higher. For an unknown reason, levels in children can be higher than in adults. Some U.S. children with the highest blood levels of PFOA overlap with the levels seen to have caused such effects as low birth weight and decreased growth in animals, according to an evaluation by the Environmental Working Group.

"The fact is that while we don't know all that we should know, what we do know is troubling," Tim Cropp, a toxicologist at the EWG, said.

Chemical fears

What they are: Perfluorochemicals, which use the elements fluorine and carbon to make non-stick and stain-resistant coatings. Perfluorochemicals have a molecular structure that prevents them from mixing well with water or oil.

Scientists in the United States have zeroed in on two members of this chemical family as particularly worrisome: perfluorooctanoic acid, or PFOA for short, and perfluorooctanyl sulfonate, or PFOS. The chemicals have been used to make some of the world's most famous brand names, including Teflon and Scotchgard.

Where are they found: Some fast-food wrappers, water-repellant clothing, stain-resistant clothing and carpets, non-stick cookware, pizza boxes, microwave popcorn containers, nail polishes and shaving cream.