The fluoropolymer industry has long faced scrutiny under the broad umbrella of PFAS (per- and polyfluoroalkyl substances), often grouped with substances with vastly different properties and safety profiles. However, a new peer-reviewed study, A Critical Review of the Application of Polymer of Low Concern and Regulatory Criteria to Perfluoropolyethers, offers more compelling evidence that PFAS should not be regulated as a single class. This study examines the properties of high molecular weight, non-functionalized perfluoropolyethers (PFPEs) and concludes that they are distinct, low-risk substances.
Why PFPEs Are Different from Other PFAS
PFPEs are high-performance, synthetic lubricants used in aerospace, medical, semiconductor, automotive, and many other economically vital industries. Their unique chemical structure—large molecular weight, narrow molecular weight distribution, and extreme chemical stability—makes them fundamentally different from small-molecule PFAS like PFOA or PFOS, both of which were phased out by industry more than a decade ago.
Key Findings from the Research
The study rigorously evaluates four commercially available PFPEs and finds that they meet criteria that can be used to identify polymers of low concern (PLC) for potential human or environmental impacts. They are found to be chemically inert, thermally stable, environmentally immobile, and do not degrade into harmful byproducts under normal use or disposal conditions. They are shown to be non-bioaccumulative, non-bioavailable, insoluble in water, and highly stable under foreseeable use conditions.
Manufacturing and Life Cycle Impacts
The study goes beyond chemical properties to examine life cycle impacts, including manufacturing emissions and end-of-life disposal. The PFPEs examined in the study are manufactured without polymerization aids (either fluorinated or not), and the manufacturing and subsequent purification processes help ensure negligible residual monomers and leachables. Importantly, the manufacturers that contributed data to the study have publicly committed to responsible manufacturing practice standards.
End-of-Life Considerations
At end-of-life, the PFPEs in the study are typically used in trace amounts within larger equipment, enabling safe disposal through metal recycling or high-temperature incineration. The study acknowledges data gaps in incineration and landfill degradation but emphasizes that, based on their chemical and physical properties, the PFPEs covered in the study are unlikely to break down into harmful substances under normal conditions.
Why Science-Based Regulation Matters
One of the most important takeaways from this research is the call for science-based regulation. The current public discourse around PFAS often lacks a solidly scientific foundation, leading to blanket restrictions that fail to differentiate between substances that do or don’t have characteristics that might raise questions about potential risk.
The Take-Home Message for Policymakers
This study provides a robust scientific foundation for excluding high molecular weight, non-functionalized PFPEs from such generalized bans.
We urge policymakers, regulators, and stakeholders to embrace a science-based approach that recognizes the clear distinctions among different types of PFAS.