Comprehensive Assessment of Poly- and Perfluoroalkyl Substances in China: Flows, Stocks, and Emissions from Polytetrafluoroethylene

Polytetrafluoroethylene (PTFE), the main fluoropolymer product, is a major source of poly- and perfluoroalkyl substances (PFAS) in the environment. This study presents a comprehensive life cycle assessment of PTFE-associated nonpolymeric PFAS in China, using dynamic material flow analysis to quantify nonpolymeric PFAS flows, stocks, and emissions across all PTFE life stages from 2020 to 2050 and to reveal how regulatory policies drive compositional shifts in China's relevant substances. Specifically, our results revealed significant growth in total nonpolymeric PFAS flows in 2023, with the average estimate of total nonpolymeric PFAS emissions reaching 1.06 × 10⁵ kg, 95.5% of which originated from PTFE production. Under a high estimate, in-use perfluorooctanoic acid (PFOA) stocks surged from 21.0 kg in 2000 to 1.22 × 10³ kg in 2019, and then reduced by 76.5% by 2050. These results align with China's PFAS phase-out measures under the Stockholm Convention. Importantly, our results showed a regulatory-induced PFAS compositional transformation. By 2050, emerging PFAS will dominate relative to legacy perfluoroalkyl acids (PFAAs) (3.64 × 10⁴ kg): emerging PFAAs (2.30 × 10⁴ kg), perfluoroalkyl ether carboxylic acids (8.24 × 10³ kg), fluorotelomer sulfonic acids (1.11 × 10⁴ kg), and other PFAS. As China's first life-cycle inventory study of PTFE-associated nonpolymeric PFAS, this research provides critical PFAS management insights and identifies production-phase controls as the most effective intervention point.