Late lessons from early warnings on PFAS

Abstract

Achieving compliance with recent per- and polyfluoroalkyl substances (PFAS) regulations in the United States and Europe will require substantial effort and funding by municipal water providers, as well as chemical and product innovation to avoid regrettable substitutions. Despite emerging knowledge of the potential persistence, bioaccumulation and toxicity of these substances already several decades ago, regulatory action has only been taken in the last few years. Here we examine the background for this late regulatory action, whether early warning signs were overlooked, and whether regulatory or market actions could have been taken earlier. We find that problems in defining PFAS as a group of substances, including extrapolating hazard information from perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) to other PFAS substances, have hampered the effective protection of public health and the environment. Moreover, because PFAS chemistry uniquely imparts useful functionality in a wide range of applications, many uses may be hard to replace without either modifying performance specifications for certain applications or carrying out substantial research and development and scaling of safer replacements. Most importantly, regulatory frameworks in the United States and the European Union have not been suited to group-based assessments, but are rather aimed at chemical-specific, case-by-case risk assessment and management. Even in these cases, too little emphasis has been put on using persistency as a crucial early warning property before full evidence of the hazards of individual PFAS compounds was available. We hope that this analysis provides additional insights into discussions and actions on PFAS and contributes to earlier action on other potentially hazardous chemicals and/or chemical classes. Concern about the potential health and environmental hazards of substances known as PFAS have led to strong regulations, especially in Europe and the United States. This Perspective examines whether early warnings were followed and whether lessons can be learned from the way the chemicals were dealt with since their discovery.