RELEASE CHEMICALS
In what sounds like bad news to all the cooks of the world who have come to rely on their non-stick pots and pans, a study conducted by the University of Toronto, Environment Canada, and the University of Guelph says these surfaces release a variety of chemicals into the environment when heated.
Writing in the journal Nature, researchers from these institutions say when heated, products containing Teflon and other fluorinated compounds release chemicals that include trifluoroacetic acid (TFA), a persistent compound whose long-term effects on the environment are unknown, trace amounts of ozone-destroying chlorofluorocarbons (CFCs), and longer-chain perfluorocarboxylates, which accumulate in animal tissues.
The researchers said instead of using CFCs, which damage the ozone layer, manufacturers of refrigeration systems, aerosols, Styrofoam, and other products have turned to hydrochlorofluorocarbon (HCFCs) and hydrofluorocarbon (HFCs) gases. While these gases break down in the atmosphere (unlike CFCs), they form TFA as a byproduct, which is then brought back to Earth when it rains.
"By measuring TFA levels in rainwater over the last three to four years, researchers estimated there should be 100 to 120 parts per trillion in the water by the year 2020," says David Ellis, lead author of the study. "We unexpectedly discovered the TFA levels have far exceeded that amount and we wanted to know why."
Thinking that fluorinated polymers like Teflon might be involved, the researchers heated products containing fluoropolymers at various temperatures and found they emitted up to 10 percent of TFA. Although the effect of TFA on people is unknown, the researchers say the release of this compound should be cause for worry.
"High concentrations of TFA in water can be mildly phytotoxic (toxic to plants) but, more importantly, it will take decades for TFA to degrade," says University of Toronto chemistry professor Scott Mabury, who supervised the study. "We don't know what the long-term environmental impacts are."
The scientists also found that fluoropolymer material releases small amounts of CFCs into the atmosphere, which can contribute to ozone depletion.
|
Click below to e-mail this article to a friend |
|---|
Written by: David Ellis & Scott Mabury, University of Toronto Department of Chemistry
RELATED LINKS:
| * * * IN-HOUSE RESOURCES * * * |
|---|
