The new Mark Ruffalo film Dark Waters puts highly fluorinated chemicals firmly back in the public spotlight, for good reason. Toxic PFAS pollution is now widespread, but the scene is dominated by vested interests seeking to maintain the status quo. With the EU set to announce the most wide-reaching reform of chemical safety laws in over a decade, including a PFAS action plan and ECHA restriction proposals, understanding this dense field is more crucial than ever. We have brought together four top independent researchers to explain the current state of knowledge for all professionals dealing with or interested in PFASs.