what's Cooking? When heated, Teflon product of persistent chemicals.
Teflon pans are a wonder for flipping pancakes, but they become less effective over time. This decrease can be more than a nuisance culinary, scientists report in the July issue 19 Nature : Teflon breaks down into potentially harmful chemicals that persist in the environment and can kill plants for high concentrations. So far, however, there is no evidence that the levels are harmful.
The chemical, known as trifluoroacetate (TFA) occurs widely in the environment. The bulk results from the decomposition of compounds known as hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs). But in many places, TFA levels in rainwater are too high to be explained by HCFCs and HFCs, only a gap that has puzzled researchers for nearly a decade. University of Toronto chemist Scott Mabury and colleagues undertook a systematic search for other possible culprits. Teflon and parents - which are used in many household and commercial contexts - seemed strong candidates because of their chemical composition and wide usage. But could really produce Teflon ventilation TFA?
To find out, Mabury and colleagues characterized the compounds that are formed when pure Teflon, and various Teflon products, were heated. Experiments were conducted at a variety of temperatures up to 5001 / 4C to simulate both standard baking and combustion of waste. They found that not only Teflon decomposition product TFA, but a suite of related molecules with unknown environmental effects. A computer simulation based on the data showed that Teflon and HCFC / HFC together could explain the TFA concentrations observed in Toronto, suggesting that Teflon was the source TFA hidden.
Although trivial at its current level, TFA can persist in the environment for centuries, which could allow it to reach concentrations that can harm plants, said Tim Wallington, a specialist environment to the Ford Motor Co. in Dearborn, Michigan. But there is no cause for immediate alarm, "I do not think we should stop using Teflon," he said. "I just think that, in hindsight, we should have been better" environmental testing.
Related Sites
website about Teflon by DuPont, the company that produces it
homepage Scott Mabury
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