Teflon's sticky situation

If Teflon is non stick, how do they get it stick to the pan?

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.

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.

"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.

"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,"

Dr Tim Kropp, a toxicologist working for environmental activists 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.

Last year the British government called for a related chemical, perfluorooctane sulphonate (PFOS), to be withdrawn.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.