This study zooms in on public governance in the Baltic Sea region of three generations of notorious hazardous substances, namely, PCBs, PBDEs and PFOS/PFOA. Following regulation, PCB concentrations in the Baltic Sea have decreased substantially although they are still above pre-industrial levels. PBDE levels have also decreased in some places, but they too are well above targeted levels, whereas the situation for PFOS and in particular for PFOA has hardly improved at all. In the case of PCBs, while comprehensive measures took long to implement, initial preventive measures were taken early based on the precautionary principle. This contrasts with the cases of PBDEs, PFOS and PFOA, where the burden of proof on policy-makers has been high and hence caused severe delays in policymaking. There has, however, generally been a positive interplay in all three cases between the EU, which has legislated, and HELCOM, which has taken the role of concept and agenda setting. While environment-oriented policies, such as the Ecosystem Approach to Management under MSFD and BSAP, have grown in importance over time, polluter-oriented chemical legislation has been more important when it comes to final decision-making. Nevertheless, the general response has been reactive rather than proactive, and there is no indication that society responds faster today than in the past, at least not given the fact that awareness, experience and knowledge are greater today than a few decades back. Based on that insight, the article discusses various options for improving governance.