By Robert L. Wolke
Special to The Washington Post
Wednesday, February 1, 2006
Last week's news about U.S. manufacturers' gradual elimination of a certain chemical from their factory emissions and products with nonstick coating caused home cooks to look askance at some of their kitchen equipment. We asked "Food 101" columnist and chemistry professor Robert L. Wolke for his take on the matter.
Maybe it's a sign of our times, but who would have expected stories about a chemical compound called perfluorooctanoic acid to strike fear in the hearts of cooks?
But the recent news led one authority to say, "I certainly wouldn't use a Teflon fry pan."
What's the connection?
PFOA is used in the manufacture of fluorine-containing polymers, materials such as Teflon that repel water and resist staining by oil and grease. In addition to nonstick cooking surfaces, consumer applications include microwave popcorn bags and pizza delivery boxes.
Although many chemists would be hard-pressed to tell you exactly what PFOA is, it hit the front page of The Post and other newspapers around the world Thursday, after the U.S. Environmental Protection Agency asked eight U.S. chemical companies to substantially reduce and eventually eliminate the chemical from its products and plant emissions. They agreed to do so.
Why? Because PFOA -- a synthetic industrial chemical that as far as we know does not exist in nature -- is, according to the EPA, "very persistent in the environment, [has been] found at very low levels both in the environment and in the blood of the general U.S. population, and [has] caused developmental and other adverse effects in laboratory animals." Although research on the environmental and health implications of PFOA has been fragmentary and no correlation between PFOA exposure and human cancer has been found, calls are being made in the United States and as far away as Australia to ban the chemical entirely.
Most nonstick cooking surfaces are made of Teflon, or polytetrafluoroethylene. And PFOA is one of the intermediate chemicals used in the chain of chemical-reaction steps that produce it. But the PFOA is virtually all gone before the final material comes off the production line. Intermediate chemicals of one kind or another are part of virtually all chemical manufacturing processes and are not allowed to contaminate the final product.
Teflon is microscopically smooth and nonporous (one of the reasons nothing sticks to it). Even if it does harbor trace amounts of PFOA, which is all anyone has suggested, the PFOA is unlikely to seep into food or escape into the air in kitchens -- unless, of course, an empty nonstick pan were abandoned on a hot burner, because above 600 degrees or so (a temperature rarely reached in cooking), the Teflon would begin to decompose into toxic fumes.
Before we even see a nonstick pan in the store, its coating already has been heated to high temperatures during manufacturing, partly to get rid of any residual PFOA. In my opinion, PFOA in the environment probably came from factory emissions, perhaps during the high-temperature phases of manufacturing. That's certainly more plausible than blaming me for frying an egg in my nonstick pan.
Susan B. Hazen, acting assistant administrator of the EPA's Office of Prevention, Pesticides and Toxic Substances, has been quoted as saying, "The science is still coming in." But she adds that eliminating PFOA "is the right thing to do for our health and our environment."
So should we throw away all our nonstick cookware, eschew microwaved popcorn and stop ordering delivery pizza? Some historical parallels exist. On the theory that the mercury in silver-amalgam tooth fillings causes an array of illnesses, some people have had all their fillings removed. And believing that aluminum causes Alzheimer's disease, some people have thrown away all their aluminum pots and pans. If we also throw away our nonstick pots and pans, how are we ever going to cook food to be chewed by our mercury-free teeth?
I quote from the EPA's Web page ( http://www.epa.gov/oppt/pfoa/pfoainfo.htm ): "At present, there are no steps that EPA recommends that consumers take to reduce exposures to PFOA because the sources of PFOA in the environment and the pathways by which people are exposed are not known. Given the scientific uncertainties, EPA has not yet made a determination as to whether PFOA poses an unreasonable risk to the public. At the present time, EPA does not believe there is any reason for consumers to stop using any consumer or industrial related products that contain PFOA."
So please excuse me while I go fry an egg in my Teflon pan.