Who pays for PFAS contamination? A comparative analysis of environmental liability in the US and Sweden

Abstract Environmental liability systems worldwide face mounting challenges addressing contamination from persistent chemicals, particularly when contamination spans decades and involves activities that were legal when performed. This article examines how the US and Sweden allocate responsibility for contaminated site remediation through their distinct legal frameworks. Using functional comparative methodology, the research analyses the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) against Sweden's Environmental Code, using PFAS contamination to demonstrate how each system addresses emerging persistent contaminants. Analysis of PFAS contamination reveals that CERCLA's rule‐based system maximises private sector cost recovery through retroactive liability but generates substantial transaction costs, as evidenced by over 6400 litigation cases and billions in corporate reserves. Sweden's standards‐based system provides contextual fairness through temporal boundaries and reasonableness assessments based on historical context, with landmark PFAS cases demonstrating judicial flexibility in addressing persistent contaminants while the system relies more heavily on public funding. The PFAS experience exposes limitations in both systems when addressing widespread contamination from substances whose environmental persistence and health effects were not understood until decades after deployment, demonstrating the need for adaptable frameworks that balance comprehensive cleanup with fair treatment of historical actors.