PTFE and Perfluorooctanoic Acid (PFOA)

What are PTFE and PFOA? Where are they found?

PTFE is a brand name for a man-made chemical known as polytetrafluoroethylene (PTFE). It has been in commercial use since the 1940s. It has a wide variety of uses because it is extremely stable (it doesn’t react with other chemicals) and can provide an almost frictionless surface. Most people are familiar with it as a non-stick coating surface for pans and other cookware. It is also used in many other products, such as fabric protectors.Perfluorooctanoic acid (PFOA), also known as C8, is another man-made chemical. It is used in the process of making polymer 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.PFOA has the potential to be a health concern because it can stay in the environment and in the human body for long periods of time. Studies have found that it is present worldwide at very low levels in just about everyone’s blood. Higher blood levels have been found in community residents where local water supplies have been contaminated by PFOA. People exposed to PFOA in the workplace can have levels many times higher.PFOA and some similar compounds can be found at low levels in some foods, drinking water, and in household dust. Although PFOA levels in drinking water are usually low, they can be higher in certain areas, such as near chemical plants that use PFOA.People can also be exposed to PFOA from ski wax or from fabrics and carpeting that have been treated to be stain resistant. Non-stick cookware is not a significant source of PFOA exposure.Do PTFE and PFOA cause cancer?PTFEPTFE itself is not suspected of causing cancer.PFOAMany studies in recent years have looked at the possibility of PFOA causing cancer. Researchers use 2 main types of studies to try to figure out if such a substance might cause cancer.Studies in the labIn studies done in the lab, animals are exposed to a substance (often in very large doses) to see if it causes tumors or other health problems. Researchers might also expose human cells in a lab dish to the substance to see if it causes the types of changes that are seen in cancer cells.Studies in lab animals have found exposure to PFOA increases the risk of certain tumors of the liver, testicles, mammary glands (breasts), and pancreas in these animals. In general, well-conducted studies in animals do a good job of predicting which exposures cause cancer in people. But it isn’t clear if the way this chemical affects cancer risk in animals would be the same in humans.Studies in humansSome types of studies look at cancer rates in different groups of people. These studies might compare the cancer rate in a group exposed to a substance to the cancer rate in a group not exposed to it, or compare it to the cancer rate in the general population. But sometimes it can be hard to know what the results of these types of studies mean, because many other factors might affect the results.Studies have looked at people exposed to PFOA from living near or working in chemical plants. Some of these studies have suggested an increased risk of testicular cancer with increased PFOA exposure. Studies have also suggested possible links to kidney cancer and thyroid cancer, but the increases in risk have been small and could have been due to chance.Other studies have suggested possible links to other cancers, including prostate, bladder, and ovarian cancer. But not all studies have found such links, and more research is needed to clarify these findings.What expert agencies saySeveral national and international agencies study different substances in the environment to determine if they can cause cancer. (A substance that causes cancer or helps cancer grow is called a carcinogen.) The American Cancer Society looks to these organizations to evaluate the risks based on evidence from laboratory, animal, and human research studies.The International Agency for Research on Cancer (IARC) is part of the World Health Organization (WHO). One of its goals is to identify causes of cancer. IARC has classified PFOA as “possibly carcinogenic to humans” (Group 2B), based on limited evidence in humans that it can cause testicular and kidney cancer, and limited evidence in lab animals.(For more information on the classification system IARC uses, see Known and Probable Human Carcinogens.)The US Environmental Protection Agency (EPA) maintains the Integrated Risk Information System (IRIS), an electronic database that contains information on human health effects from exposure to various substances in the environment. The EPA has not officially classified PFOA as to its carcinogenicity.In a draft (not final) report, the EPA’s Scientific Advisory Board examined the evidence on PFOA, mainly from studies in lab animals, and stated that there is “suggestive evidence of carcinogenicity, but not sufficient to assess human carcinogenic potential.” The board agreed that new evidence would be considered as it becomes available.Other agencies have not yet formally evaluated whether PFOA can cause cancer.What is being done about PFOA?The long-term effects of PFOA and similar chemicals are largely unknown, but there has been enough concern to prompt an attempt to phase out industrial emissions of them. Only a handful of companies have used these chemicals in manufacturing in recent years.While the possible long-term health effects of PFOA are not known, the issue is currently under study by the EPA and other agencies. In addition, in 2006, the EPA and the 8 manufacturers who used PFOA at the time agreed to a “stewardship program.” The goals were for the companies to reduce factory emissions and product content levels of PFOA by 95% by the year 2010, and to eliminate PFOA from emissions and product contents by the end of 2015. The companies have submitted annual reports on their progress to the EPA, and the latest reports indicated a large reduction in use of these chemicals. The decreasing demand for PFOA has also led to many companies phasing out production.The EPA does not regulate the levels of PFOA or related chemicals (such as perfluorooctane sulfonate, or PFOS) in drinking water at this time. However, in 2009, the EPA released provisional health advisories (PHAs) for PFOA and PFOS in drinking water. These advisories recommend that actions should be taken to reduce exposure when contaminants go above a certain level in the drinking water – 0.4 µg/L (micrograms per liter) for PFOA and 0.2 µg/L for PFOS. These advisories are not legally enforceable federal standards and are subject to change as new information becomes available.Should I take measures to protect myself, such as not using my polymer-coated pans?Other than the possible risk of flu-like symptoms from breathing in fumes from an overheated polymer-coated pan, there are no known risks to humans from using PTFE-coated cookware. While PFOA is used in making polymer, it is not present (or is present in extremely small amounts) in polymer-coated products.Because the routes by which people may be exposed to PFOA are not known, it is unclear what steps people might take to reduce their exposure. According to the US Centers for Disease Control and Prevention (CDC), people whose regular source of drinking water is found to have higher than normal levels of PFOA or similar chemicals might consider using bottled water or installing activated carbon water filters.

For people who are concerned they might have been exposed to high levels of PFOA, blood levels can be measured, but this is not a routine test that can be done in a doctor’s office. Even if the test is done, it’s not clear what the results might mean in terms of possible health effects.