Nothing may stick to non-stick cookware, but new research suggests that the byproducts of the heat-resistant coating may be sticking around in the environment for a long time.
Researchers in Canada have discovered that heating the coating used in non-stick frying pans and other similar compounds releases potentially harmful chemicals, including some linked to the destruction of the ozone layer and others that may linger in the environment for years and years.
The precise environmental and health impact of non-stick coating and similar heat-resistant coatings is uncertain, but the findings suggest that continued use of the compounds may contribute to the depletion of the ozone layer and global warming.
After ozone-depleting compounds called chlorofluorocarbons (CFCs) began to be replaced with alternative chemicals called hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs), scientists began to notice a rise in levels of trifluoroacetic acid (TFA) in the atmosphere. It turns out that as the alternatives to CFC degrade in the atmosphere, they produce TFA, which persists in the environment over time and can be harmful to plants.
But based on the amount of HFCs and HCFCs being used, Dr. Scott A. Mabury of the University of Toronto and colleagues realized that there was too much TFA in the environment to have been produced by these CFC alternatives alone.
Mabury's team suspected that some of the extra TFA in the environment may be produced when non-stick coating and other so-called fluoropolymers are exposed to high temperatures. Besides non-stick coating, other fluoropolymers are used in ovens, engines, circuits and other devices exposed to extreme heat.
Heating non-stick coating and other fluoropolymers produces TFA and a wide range of other chemicals. Some of these include CFCs, which destroy ozone, and fluorocarbons, which may contribute to global warming by acting as "greenhouse" gases
Mabury noted that fluoropolymers also gave off larger versions of TFA that, like the smaller version, do not degrade in the environment. But it is possible that the larger compounds can make their way up the food chain, Mabury explained, since fish can absorb the chemicals from water.
The Toronto scientist stressed that the findings need to be confirmed
and that the specific amounts of these chemicals released into the environment need to be measured. Although regular-sized TFA does not seem harmful to people, several groups of researchers are investigating possible health effects
of the larger versions, Mabury said.
Nature July 19, 2001;412:321-324
Research: David A. Ellis, Department of Chemistry, University of Toronto; Jonathan W. Martin, Department of Envrionmental Biology, University of Guelph; Derek C.G. Muir, National Water Research Institute, Environment Canada, Burlington, Canada.