The Scientific Basis for Managing PFAS as a Chemical Class

Managing the risk of these “forever chemicals” has focused primarily on one chemical—out of thousands—at a time. It doesn’t work, so we must change this system to protect public health.

Foam containing PFAS in Starkweather Creek, Madison, Wisconsin

Wisconsin DNR

Today, 16 experts on PFAS (including yours truly) published an article in Environmental Science & Technology Letters, providing a scientific explanation for why a class-based approach to the nearly 8,000 separate but related PFAS chemicals is appropriate and necessary. It includes recommendations for how governments and industry can address PFAS as a class, emphasizing the importance of eliminating the use of PFAS other than those uses deemed essential, and investing in the development of safer alternatives and methods to remove existing PFAS from the environment.

To Protect Public Health, PFAS Must Be Treated As a Class

PFAS (per- and polyfluoroalkyl substances) are a class of thousands of extremely persistent chemicals that accumulate in the environment and living organisms. The use of PFAS in numerous consumer and industrial applications has led to widespread human exposure and environmental contamination. A broad range of adverse health outcomes have been linked to PFAS exposure, including kidney and testicular cancer, elevated cholesterol, liver disease, decreased fertility, thyroid problems, changes in hormone functioning, changes in the immune system, and adverse developmental effects.

Under the broken U.S. regulatory system, managing the risk of PFAS has focused primarily on one chemical—out of thousands—at a time. So it is no great surprise that this approach has not been effective at controlling widespread exposures to PFAS—as other PFAS have been rushed in to replace any restricted PFAS—and has resulted in inadequate public health protection.

This system does not work.

A class-based approach, proposed in the article published today, is a superior method for managing the human and environmental risks associated with all PFAS, including “short-chain” PFAS and fluoropolymers. While this is a departure from the traditional (largely ineffective) risk management approach, the extreme persistence, accumulation potential, and known and potential hazards of PFAS studied to date demand a more efficient and effective approach.

Chemical companies falsely assert that you can separate out “safe” types of PFAS from the class. However, there is clear science showing that PFAS contamination results from the production, use, disposal, and environmental breakdown of all the subclasses.  For example, some of the most extensive PFAS contamination, notably in the Ohio River valley, is due to industrial waste from fluoropolymer production. Claims that fluoropolymers are safe because their large size prevents them from being absorbed into our bodies willfully ignores the full life cycle of fluoropolymers.

Similarly, contrary to industry assertions, short-chain PFAS, which were presented as safer alternatives to long-chain, legacy PFAS, are not safe. Evidence now suggests that short-chain PFAS are associated with adverse health effects similar to the PFAS that they replaced. Furthermore, short-chain PFAS are still highly persistent, even more mobile in the environment than long-chain PFAS, and more difficult and expensive to treat in drinking water.

Limit PFAS Chemicals to Those Considered Essential (and Without Safer Alternatives); Phase Out All Others

Governments are increasingly using broader management approaches to control PFAS exposure, such as targeting all PFAS within certain use categories. For example, restrictions on PFAS use in firefighting foam (such as California bill SB 1044 currently being considered by the legislature), carpets and rugs, or food contact materials have been proposed and/or enacted by various U.S. states and in other countries. Additionally, the European Commission and Vermont are looking to regulate PFAS as a class in drinking water.

While this is a good start, the paper proposes a more comprehensive risk management approach to source reduction that looks beyond these product categories by limiting PFAS to only those uses considered essential for health or safety or critical for the functioning of society and where there are no safer alternatives available that are technically and economically feasible. 

To protect public health and the environment, we must restrict the use of the entire class of PFAS, allowing only those considered essential. Remediating PFAS, once released to the environment, is costly, energy-intensive, and cannot fully reverse the damage. Following this framework, several European countries recently announced a plan for phasing out all nonessential uses of PFAS by 2030.

Protect People From Toxic PFAS Chemicals

Retailers and manufacturers can also play an important role by taking the initiative to reduce their use of chemical classes of concern. Numerous factors are encouraging companies to stop using the entire class of PFAS, including increasing consumer demand for products containing fewer harmful chemicals, pressure from environmental and health groups, the desire to limit liability and costly reformulations due to regrettable substitutions (when well-studied hazardous chemicals are replaced with poorly studied but structurally similar chemicals that have the potential to be similarly hazardous), and company values. For instance, Kaiser Permanente, Levi Strauss & Co., Crate & Barrel, and member-owned retailer COOP Denmark are phasing out all PFAS based on the companies’ values. Home retailer IKEA has already achieved a complete phaseout of all PFAS in its textile products as of 2016 and the Home Depot and Lowe’s have already stopped selling carpet and rugs with PFAS as of 2020. This is great progress, but we need a much more comprehensive approach to address the full extent of risks posed by PFAS pollution. Governments need to step up and take decisive action to regulate the class of PFAS.

Cleanup Efforts Need to Focus on the Class—Not a Few Chemicals at a Time

A class-based approach to cleanup efforts is also critical. Research and development funding for monitoring, treatment, and disposal methods should prioritize techniques that are effective for the entire class of PFAS (see our recommendations for Michigan), or at least more broadly effective than the PFAS currently regulated. Regulatory agencies should account for combined exposures to PFAS (e.g., in drinking water, food, air, consumer products, and waste) and apply data and lessons learned from well-understood PFAS to less-studied PFAS when limiting uses of PFAS in commerce or setting protective cleanup levels. Establishing limits for the class rather than regulating chemical by chemical will lead to lower exposures and better protection for us all, especially vulnerable populations such as pregnant women, children, and workers.

As the paper states,

“Without effective risk management action around the entire class of PFAS, these chemicals will continue to accumulate and cause harm to human health and ecosystems for generations to come…. [M]anaging PFAS as a class is scientifically sound, will provide business innovation opportunities, and will help protect our health and environment now and in the future.”

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About the Authors

Anna Reade

Staff Scientist, Healthy People & Thriving Communities program

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