It's on saucepans, clothing, even buildings, but now Teflon - the famed non-stick chemical - is at the centre of a slippery controversy about cancer and birth defects.
By Chris Summers
BBC News Online
Since its invention in the 1930s, amateur and professional cooks alike will acknowledge their debt of gratitude to Teflon. Over the years, the non-stick coating on pots and pans has helped turn out countless perfect fried eggs and cheese soufflés.
But for how much longer? Environmentalists have called for the withdrawal of a chemical which is a key ingredient in the manufacture of Teflon because of growing health fears.
Perfluorooctanoic Acid, PFOA for short, is a synthetic chemical used in the manufacture of advanced plastics including Teflon.
Today, all new man-made chemicals must undergo rigorous testing to be marketed in Europe. But PFOA is one of 100,000 or so chemicals which avoided the test because they were invented before 1981.
Teflon was invented in the 1930s by DuPont, the US firm which uses it today to make non-stick cookware, and also markets it as a coating for clothes and carpets.
The company recently agreed to an out-of-court settlement to a class action lawsuit brought by around 50,000 residents who lived near its West Virginia plant.
Bucky Bailey's mother became pregnant while working at DuPont's West Virginia plant
The residents, who lived along the Ohio river south of Parkersburg, West Virginia, claimed the company had contaminated local water supplies with PFOA, which they alleged was linked to birth defects and other health hazards.
Among the plaintiffs was Bucky Bailey, who was born with a single nostril and a deformed face. His mother fell pregnant with him while working at DuPont's Parkersburg plant.
DuPont eventually agreed to pay $50m in cash to the plaintiffs, plus $22m in legal costs. The company also agreed to spend $10m on special water treatment facilities to filter out PFOA.
But, crucially, DuPont did not accept liability and maintained PFOA did not pose any danger to the public.
"We want to make very clear that settling this lawsuit in no way implies any admission of liability on DuPont's part," says DuPont lawyer Stacey J Mobley.
At the same time, DuPont is facing another multi-million dollar lawsuit from the US environmental watchdog for allegedly failing to disclose the results of secret water tests in 1984.
It faces being fined $27,000 for every day since 1984.
Now, environmental campaigners on both sides of the Atlantic want to ban the controversial chemical.
"PFOA accumulates in the body and in the environment and studies on animals suggest a link to birth defects. We are very concerned about it," says Karine Pellaumail, from Friends of the Earth.
Dr Tim Kropp, a toxicologist working for the Environmental Working Group in the US says tests carried out by the US firm 3M suggested high doses of PFOA led to various forms of cancer in rats.
"DuPont have some brilliant scientists and I don't believe that they couldn't find an alternative if they put their minds to it," says Dr Kropp.
'Respond with compassion'
But DuPont disagrees. "There is no evidence that PFOA is harmful," says its director of media relations, Clifton Webb. "We are very confident that there are no health effects associated with the public's exposure to PFOA at the levels we have seen."
But, he accepts that, in high enough doses, PFOA could be carcinogenic to animals.
FACTS ABOUT TEFLON
Invented in US in 1930s
1946, first marketed by DuPont as Teflon
Has the lowest coefficient of friction of any solid material known to man
Found on pots, pans, overcoats, bullets and pine lining
As for those who had suffered birth defects, such as Bucky Bailey, he says the firm would "respond with compassion and concern, but they are not related to exposure to PFOA".
According to 3M's tests, PFOA was present in five parts per billion in the bloodstream, says Mr Webb.
Workers exposed to it were likely to have a level "thousands of times higher", he concedes, but there was no evidence it was doing them harm.
As for substitutes, the company has identified around 100 possible alternatives to PFOA - which is used as a processing aid in Teflon - but none could produce the sufficient "quantity or quality" required. Cost, he says, is not an issue.
Last year the American Environmental Protection Agency (EPA) launched an investigation into the chemical's effects, a study which is being watched by the British government.
It acknowledges "considerable scientific uncertainties" on the issue but says there is no reason anyone should stop using Teflon products.
But the EPA is expected to submit a more comprehensive risk analysis next month.
Last year the British government called for a related chemical, perfluorooctane sulphonate (PFOS), to be withdrawn. It followed 3M's decision to abolish the chemical from its well-known Scotchgard products after health concerns were raised.
"PFOA is related to it but nowhere near as much research has been done into it and we are awaiting the outcome of the EPA's research," says a spokesman for Defra.
Others are seeking a more restrained response. Professor Scott Mabury, head of environmental chemistry at the University of Toronto, says a ban on PFOA would be "Draconian" and the answer was to go back to the factory and make sure residual levels of the polluting chemicals were removed in the production process.
"It's an engineering problem," he says. "It's not impossible."