You don't have to be worried about the nonstick Teflon on your pots and pans causing harm, but a new study from Canada suggests that similar fluoropolymers breaking down under extremely high temperatures could be contributing to environmental problems.
The study, published in the July 19 issue of Nature magazine, found for the first time significant releases of trifluoroacetic acid from fluoropolymers, said Scott Mabury, an associate professor of environmental chemistry at the University of Toronto. TFA can be mildly toxic to plants.
The study also said other chemicals, including those that contribute to global warming, are released from heating fluoropolymers. But how much risk, if any, that poses to people is unclear.
Wilmington, Del.-based DuPont said that the study used heat as high as 932° F, well above cooking temperature, and said it knows of no health problems from nonstick cookware.
The study generated a lot of media coverage about the safety of nonstick coatings, but Mabury said the study did not raise those issues. Mabury said no one is at risk from cooking.
What raises concerns is that many of the chemicals released bioaccumulate and do not break down in the environment.
The study found that fluoropolymers can break down into carboxylic acids, which are similar to chemicals pulled from the market last year by St. Paul, Minn.-based 3M because they bioaccumulate and ``have been linked with possible adverse health effects,'' the study said. The researchers also said some of the chlorinated fluoropolymers break down into fluorocarbons that contribute to global warming.
The study started with an effort to find the sources of TFA in rainwater. Fluoropolymers are ``likely to be a significant source of TFA in urban rainwater,'' the study said.
DuPont said that researchers already have known that fluoropolymers break down under extreme heat.
``DuPont knows of no commercial applications for its fluoropolymer products, industrial or consumer, in which the polymer's approved end uses include subjection to the temperatures used in the University of Toronto study,'' the company said in a statement.
DuPont spokeswoman Diane Shomper said there is some inconsistency between the study and DuPont data that the company is exploring.
