Science and Policy of Fluorinated Surfactants in Firefighting Foam

Abstract

The use of aqueous film-forming foam (AFFF) in firefighting activities has resulted in the release of poly- and perfluoroalkyl substances (PFAS) to soil and groundwater in numerous locations, affecting the drinking water of millions in the U.S. Regulatory attention has focused on the subclass of PFAS known as long-chain perfluoroalkyl acids, including perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), due to their ubiquitous detection in the environment and their demonstrated hazard. For instance, U.S. EPA negotiated the phase-out of PFOS and PFOA with major manufacturers and issued drinking water health advisories for both substances. As firefighting foams containing long-chain PFAS have been phased out in the U.S., they have been replaced by formulations containing short-chain PFAS, despite the similar chemical properties of the two groups and the availability of PFAS-free alternatives. The widespread adoption of foams containing short-chain PFAS rather than fluorine-free foams was driven by a number of factors, some of which are scientific, others of which reflect the interests or values of different stakeholders. This presentation will compare and contrast the chemical and toxicological properties of long-chain and short-chain fluorinated surfactants used in AFFF, as well as the newer non-fluorinated alternatives. The presentation will also examine the environmental and firefighting performance criteria that resulted in the adoption of short-chain PFAS-based foams in the U.S. The evolution of firefighting foam use in the United States will be compared with that in other countries. Understanding the full context in which chemicals policy decisions such as this one are made can help scientists and policymakers find more effective solutions.