Kathy Attar, MPH
January 5, 2015
PFCs are a family of fluorine-containing chemicals with properties to make materials stain- and stick-resistant. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are the two most common contaminants of PFCs. PFOA is used to make Teflon™ products and PFOS was used (it no longer is) to make Scotchgard® products. Little was published on PFC toxicology until the 1980s, but over the years evidence for persistent, bioaccumulative effects has emerged, raising serious public health concerns.
Widespread nature of PFCs
For decades PFCs have been released from manufacturing facilities, leading to contamination of food and certain water supplies. Exposure also occurs through consumer products, house dust and food packaging. A variety of PFCs are applied in water-, soil-, and stain-resistant coatings for clothing and other textiles, grease-resistant coatings for food wrapping materials, and other products. Analysis from the National Health and Nutrition Examination Survey (NHANES) conducted by the CDC detected PFOS and PFOA in all the people they tested. Concentrations in children tended to be higher than in adults.
Possible Human Health Effects
Evidence from animal studies dating to the late 1970s suggests a possible link between PFCs and cancer. The U.S. EPA issued a draft risk assessment of PFOA in 2005 which stated the evidence was suggestive of a cancer risk in humans. A peer review of the EPA’s risk assessment recommended that PFOA be considered “carcinogenic to humans.” For PFOS, the evidence of carcinogenicity is less extensive and less conclusive.
Immunotoxicity effects of PFOA and PFOS have recently been demonstrated. There is strong evidence suggesting that current exposure levels correlate with adverse effects on certain immune functions. One study found that PFC concentrations in mothers showed a strong negative correlation with vaccine antibody concentrations in children.
There is also preliminary research showing that in animal studies PFOAs cause weight gain and thus could be obesogens.
Current exposure limits are not health-protective
In a new study on PFCs (subscriber access only), Drs. Grandjean and Clapp illustrate how existing exposure limits are insufficiently protective, as they are based on outdated evidence. New data gleaned from animal- and population-based control studies – for example, data from approximately 70,000 Ohio and West Virginia residents who were exposed to PFOA via drinking water consumption – reflect the need for an updated standard. Immunotoxicity effects of PFOA and PFOS have recently been demonstrated in vitro and in a variety of species and models. A population-based case control analysis supports the association between PFOA exposure and both kidney and testicular cancer and suggests an association with prostate and ovarian cancer and non-Hodgkin lymphoma.
A draft risk assessment of PFOA was released by the EPA in 2006, but a final version has yet to be produced.
Chemical policy implications
The Toxic Substances Control Act (TSCA), the federal law which regulates chemicals, did not require testing of substances already in commerce at the time it was enacted in the late 1970s. Thus, toxicology studies of PFCs were not mandated, creating the situation we have today where exposure to PFCs is widespread and government-required limits may be 1,000-fold too high to protect the public.
The absence of data on the health hazards of a particular chemical does not equal safety; in fact, it could be mean the exact opposite. PFCs illustrate this point perfectly. It clearly demonstrates the need for health-protective chemical policy reform -- reform which requires hazard data for all chemicals currently on the market and for any new chemical; allows public access to this chemical data as a means of public safety, and stirs innovation of safer chemicals and products.
Ways to limit PFCs exposure
Try to avoid purchasing or using the following:
- Grease-repellent coatings often found in fast food containers such as microwave popcorn bags and pizza boxes.
- Stain-resistance treatments. Don’t choose furniture and carpets that are marketed as “stain-resistant,” and don’t apply finishing treatments such as Stainmaster.® Where possible, choose alternatives to outerwear and sportswear that has been treated for water or stain resistance.
- Personal-care products made with Teflon™ or containing ingredients that include the words ”fluoro” or ”perfluoro.” PFCs can be found in dental floss, nail polish, facial moisturizers, and eye make-up.
- Teflon™ or non-stick cookware.