Should transformation products change the way we manage chemicals?#

Authors#

Daniel Zahn, Hans Peter H. Arp, Kathrin Fenner, Anett Georgi, Jasmin Hafner, Sarah E. Hale, Juliane Hollender, Thomas Letzel, Emma Schymanski, Gabriel Sigmund, Thorsten Reemtsma

Abstract#

Persistent, mobile and toxic (PMT) and very persistent and very mobile (vPvM) substances have been recognized as a potential environmental threat requiring more attention by regulators and scientists alike, particularly since since their recent introduction as new hazard classes by the European Union. A large number of PMT and vPvM substances are likely transformation products (TPs) formed from less persistent and often less mobile precursors. To date, these TPs remain largely unrecognized and unregulated, particularly as assessing the hazards of TPs are generally not part of chemical hazard assessment. As a result, we highlight here that TPs deserve more attention in research and in chemicals regulation and management. This perspective highlights the main challenges preventing better integration of TPs into chemicals management: (1) the lack of reliable high-throughput TP identification methods, (2) uncertainties in TP prediction, (3) TP formation during (advanced) water treatment, and (4) insufficient integration and harmonization of TPs in most regulatory frameworks. A way forward to tackle these challenges and integrate TPs into chemical management is proposed.