News Coverage
Alarm bells silent on Teflon
Published November 25, 2004
Government officials in the United States are reviewing the safety of a group of chemicals used to make several non-stick and non-stain products.
Almost every day, a new range of synthetic (man-made) chemical formulations are created in laboratories around the world. Yet, few are ever tested for their potential to harm human health in the long-term.
Several thousand man-made chemicals have been produced in recent decades, and subjecting each one to extensive safety tests is impossible.
Peter Montague, editor of Rachel's Health and Environ-ment Weekly, notes that even if 1 000 of these chemicals were properly tested, it would be impossible to test the "cocktail effects" of mixing them up with each other.
"There are 41 billion possible combinations of 1 000 chemicals taken in groups of four. So even if we could test a million combinations a year, which we can't, it would take 41 000 years to complete such a battery of tests."
Richard Wiles, vice-president of the Environmental Working Group (EWG) has also highlighted several pitfalls in chemical safety regulation.
Wiles said last year that less than 50% of new chemicals screened by the US Environmental Protection Agency (EPA) were backed up with basic toxicity tests.
Eight out of 10 new chemicals would get approval in less than three weeks, at an average rate of seven a day.
Wiles said that most people assume that chemicals in consumer products are thoroughly tested before they are sold - yet there was no legal requirement to test most chemicals for health effects at any stage of production, marketing or use.
"Because of this, basic tox-icology studies on Teflon, Scotchgard and related chemicals are being conducted only now, fifty years after these chemicals went on the market," claims the EWG.
Wiles said there was no requirement on the chemical companies to monitor for the presence of their products in the environment or human population.
"When we look behind the curtain, what we have is an industry that opposes mandatory animal testing on its chemicals (except pesticides), complains constantly about the costs (of pesticide testing) and systematically stymies research into the extent to which it is contaminating the human race with its products."
Wiles said studies were designed to divert attention from the most serious health effects - those which occur in the foetus or infant.
In a recent series of articles entitled "The Chemical Wars", Rachel's editor Peter Montague also criticised the risk-assessment approach favoured by many industries.
"Risk assessment favours corporate purposes as it involves large quantities of scientific data, all of it subject to limit-ations and uncertainties that can be disputed forever, without resolution," says Montague.
"Corporate scientists-for-hire can select and manipulate data and choose particular assumptions (often silently), allowing them to reach almost any conclusion they set out to reach, yet still package it as 'science'."
The chief medical officer of the 3M chemical company expressed "complete surprise" in May 2000 when man-made perfluorinated chemical compounds (PFCs) were found in American blood bank samples dating back to the 1950s.
The discovery was unexpected, since these chemicals are not found in nature, and the producers have always insisted that only minute "trace" amounts were expected to enter the general environment.
Yet the first warnings ap-peared more than 24 years earlier, when American dentist Dr Donald Taves found perflu-oro-octanoic acids (PFOA) in a sample of his own blood.
Taves speculated at the time that humanity had been con-taminated with tiny amounts of fluoride compounds from commercial products. He didn't mention Scotchgard or Teflon by name, but suggested that the source of his own blood pollution was linked to "water and oil repellents" used to treat fabrics and leather.
By the late 1990s, Taves's predictions were confirmed by 3M researchers when they started to draw blood bank samples from several US cities and remote parts of the Chinese countryside. The blood bank specimens were intended for use as control samples to compare with chemically-polluted blood from 3M factory workers.
The blood of 600 American children was analysed, showing that 19 out of every 20 samples had traces of PFOA and other perfluorinated compounds.
The only "clean" samples were collected from Korean War military recruits between 1948-1951 - roughly the time when PFC compounds went into commercial production.
The tests on children's blood were particularly worrying because some samples showed PFC levels higher than adult blood. The levels of one of these compounds also pointed to Scotchgard as the possible source. EWG scientists speculated that children were exposed to higher levels of these chemicals either because of their behaviour, or different metabolisms.
Evidence showed that PFC compounds were resisting natural degradation in sewage sludge, suggesting that they were even more long-lasting than chemicals such as DDT and Dieldrin.
Supermarket food samples collected in 1999 revealed PFCs in beef, bread, apples and other foods in cities where there were no chemical factories. Similar results were found in wild animals, birds and fish worldwide.
According to the EWG, the chemical group with the highest concentration and broadest distribution in wildlife was closely linked with Scotch-gard's older PFCs.
The EWG has also brought to light confidential company correspondence which suggests DuPont discussed dumping its Teflon production agent PFOA in 1984.
In a recent memorandum to the head of the US environmental protection agency, EWG scientist Dr Kristina Thayer claimed DuPont had known of cleaner Teflon production methods for at least seven years.
DuPont says . . .
DUPONT agrees it is not a good idea to expose pet birds to the fumes from over-heated Teflon cooking pans, aerosols or even burned butter.
The company says birds have "particularly sensitive" lungs, but it vehemently denies charges that its non-stick cookware is unsafe, or that products should have warning labels.
"Independent US government agencies have studied the non-stick coating and approved its use."
But the US Environmental Protection Agency does not seem convinced by some of the claims and is pressing for a thorough safety review and new data on human exposure to Teflon-related chemicals.
However, the EPA says it is not recommending any steps to consumers right now, simply because all the sources of perfluoro-octanoic acids and exposure routes are not known yet.
"EPA does not believe there is any reason for consumers to stop using any consumer or industrial related products."
DuPont also says there is no danger for people who eat particles of Teflon which flake off old, over-heated pans. "If eaten, they pass through the body and are not absorbed."
Yet the company's responses are carefully worded.
"Cookware coated with Teflon non-stick is safe at cooking temperatures up to 260 degrees Celsius, which is beyond the temperature that foods are normally prepared."
It recommends using only "low" or "medium" heat settings for its cookware.
Though it opposes warning labels, DuPont says non-stick cookware "should not be left unattended or allowed to reach extreme temperatures". Neither should food be cooked in poorly-ventilated areas.
What happens if Teflon cookware is "over-heated"?
According to DuPont, the food "will most likely burn to an inedible state" before non-stick coatings are damaged or decomposed.
Are the fumes from over-heated Teflon harmful?
According to DuPont, "excessive exposure to any form of household fumes should be avoided".
It recommends that pet birds should be kept out the kitchen - but the company is silent about the exact consequences for humans exposed to these fumes.
It also draws a distinction between Teflon non-stick chemicals on one hand, and chemicals which are used in the manufacturing process of Teflon.
"Testing so far shows that non-stick cookware sold under the Teflon brand does not contain PFOA."
It also denies that there is "any scientific evidence that low levels of exposure (to this chemical) can cause adverse human health effects in any segment of the population."
As for its anti-stain treatments for carpet and clothes, DuPont admits there is evidence that some of the chemicals "may transform to create very small, trace amounts" of PFOA.
It acknowledges that this chemical can cause animal cancer, but denies it is a proven human carcinogen or developmental toxin.
"PFOA has been wrongfully represented as a health risk when, in fact, it has been used safely for more than 50 years with no known adverse health effects to human health," said senior company spokesman Richard Anguilot.
Nevertheless, kitchen experiments conducted by the Environmental Working Group health watchdog cast doubt on several DuPont safety claims.
In May 2003 the group tested several non-stick cooking pans, including a Teflon product.
It says the heating experiments showed that Teflon coatings start to break down and emit toxic gases "through the common act of pre-heating a pan, on a burner set on high."
Full details of the EWG kitchen tests can be found at http://www.ewg.org/reports/toxicteflon/es.php.
DuPont's perspectives can be found at www.teflon.com.