The Environmental Protection Agency said that perfluorooctanoic acid (also known as PFOA or C-8) is a known carcinogen in lab rats. It's effect on humans is not yet certain as these findings were described by the agency as 'preliminary.'

Lab rats exposed to C-8 had an increase in cholesterol and triglycerides in their blood and also had a higher risk of developing cancer of the liver. The substance also showed up in the breast milk of the rats being tested which concerned scientists for the health of the infant children of people exposed to the substance.

Teflon itself does not contain any C-8. It is used in the process of making Teflon, however. So using a nonstick pan is not a danger but manufacturing one may be.

The EPA study said the agency 'has concerns with respect to the potential nationwide presence of PFOA in blood and with the potential for developmental and other effects suggested by animal studies, there are significant uncertainties in the agency's quantitative assessment of the risks of PFOA.'

Du Pont, the maker of Teflon, continues to insist there is no harm to humans. The EPA is not so sure. Further lab tests are scheduled to make a more definite determination.