Opinion: Chemists must learn from PFAS to avoid similar mistakes

What was once celebrated as a triumph of chemical ingenuity now compels the chemistry community to confront the long-term consequences of designing molecules to endure. Per- and polyfluoroalkyl substances (PFAS), widely known as forever chemicals, illustrate one of modern chemistry’s most uncomfortable paradoxes: materials engineered for exceptional performance have become liabilities precisely because they work so well.Developed for resistance to heat, water, and chemical degradation, PFAS enabled advances across consumer products, industrial processes, medical devices, and firefighting foams. Those same properties, however, have ensured that many PFAS persist in the environment and in human bodies on generational timescales.This moment calls for more than retrospective concern. Chemists now face a reckoning over how persistence is defined, rewarded, and regulated and how lessons from PFAS are carried forward into future chemical design. The choices made now will help determine whether PFAS remain a singular failure or a pattern repeated under different names.The scale of the PFAS challengeThe scale of the PFAS challenge is amplified by the sheer size and diversity of the chemical class. Thousands of PFAS are known today, spanning a wide range of structures and applications. Many remain poorly characterized in terms of toxicity, environmental fate, and long-term exposure. Their extensive use has resulted in global distribution, with PFAS detected not only near industrial sites but also in remote regions far removed from manufacturing activity. This ubiquity highlights the limits of regulatory frameworks that were never designed to manage large classes of highly persistent substances.Scientific evidence linking PFAS exposure to