Teflon® is a brand name for a man-made chemical known as polytetrafluoroethylene (PTFE) and it has been used since 1940s (discovered by DuPont Co.). Perfluorooctanoic acid (PFOA, also known as C8) is another man-made chemical and it is used in the process of making Teflon and similar chemicals (known as fluorotelomers), although it is burned off during the process and is not present in significant amounts in the final products.
Teflon itself is not suspected of causing cancer, but PFOA has the potential to be more of a health concern because it can stay in the environment and in the human body for long periods of time. Studies have found that PFOA is present at very low levels in just about everyone's blood in the US and it can be found at low levels in some foods, drinking water, and in household dust. It can be higher in areas due to contamination. People can be exposed to PFOA from fabrics, ski wax or carpeting which has been treated to be stain resistant. However non-stick cookware is not a significant source of exposure.
Studies in laboratory animals have found that PFOA exposure increases the risk of certain tumors of the liver, testicles, mammary glands, and the pancreas in these animals. Overall, well-conducted animal studies do a good job predicting that cause cancer in humans exposures. But for PFOA, there are clear differences in the way the body of laboratory animals and humans handle this chemical. 225
Because of these differences, it is clear that the process chemical to cause cancer in animals also occur in humans.
Human studies have shown that people with workplace exposure to PFOS have a higher risk of cancer of the bladder and kidneys.
Several national and international agencies studying various substances in the environment, to determine if they cause cancer (carcinogens, substances that cause cancer and help cancer grow). However, at this time, these agencies do not formally assessed whether PFOA can cause cancer. The US Environmental Protection Agency (EPA), an electronic database that contains information on human health effects from exposure to various substances in the environment, has not officially classified PFOA as to its carcinogenicity.
Other than the possible risk of fumes from overheating the pan, there are no known risks to humans using Teflon-coated cookware. When PFOA is used to make Teflon, does not occur (or not present in very small amounts) in a Teflon-coated products. Because the way by which people may be exposed to PFOS are not known, it is not clear what steps to take for people to reduce exposure.
Currently, EPA states:
"Consumer products made with fluoropolymers and fluorinated telomers, such as Teflon and other trademark products, are not PFOA. PFOA is used as a processing aid in the manufacture of fluoropolymers and can be also be produced by the breakdown of some fluorinated telomers. The information that EPA has available does not indicate that the routine use of consumer products poses a concern. At present, the EPA does not recommend any steps for consumers to take to reduce exposures to PFOA."
Source: Teflon and Perfluorooctanoic Acid (PFOA) at Cancer.org 362