The unintentional role of chemical regulation in regrettable substitution:The case of PFAS

As we approach a century since their discovery, per- and polyfluoroalkyl substances (PFAS) have become integral in various applications, from medical devices and electronics to home and personal care products, due to their unique properties. However, PFAS are now recognised for their persistence, bioaccumulation, toxicity, and mobility (PBTM), posing significant risks to human health, and the environment. Regulating complex chemicals has historically been challenging, which is exemplified with the case of PFAS and the regrettable substitutions of one PFAS with another. As a response to changing regulations, the chemical industry has introduced a plethora of replacement substances, often with shorter chains, which are still persistent and mobile. We highlight the inadequacies in regulatory responses to global spread of PFAS, revealing an unintentional role that the approach to chemical management can create in regrettable substitution. To improve chemical regulation, we propose evaluating substances prior to issuance of registration numbers, comprehensive evaluation of policy impacts, such as the universal PFAS restriction, the need to harmonise the fragmented regulatory frameworks and encourage integration and communication both nationally and globally