ABSTRACT The transition to fluorine-free firefighting foams has revealed that per- and polyfluoroalkyl substances (PFAS) can remain adsorbed on material surfaces and undergo slow desorption over time. This phenomenon results in the unintended contamination of fluorine-free replacement foams, continuing the environmental spreading of PFAS. Through an extensive review of peer-reviewed literature and supplementary data from direct contacts, this study consolidates current knowledge on the issue, representing one of the most comprehensive analyses to date. Existing research consistently identifies this as a significant challenge requiring attention. This review synthesizes findings from various studies, highlighting that certain cleaning agents and methodologies tend to demonstrate greater efficacy in removing PFAS residues compared to water. Proprietary products and available performance data were also evaluated; however, the range of such products remains limited, and for several, no conclusive evidence supports some of them to be superior to water. The most promising decontamination strategies involve a combination of water and co-solvents, potentially augmented by extreme pH conditions. To accurately assess the effectiveness of PFAS decontamination methods, a multi-faceted analytical approach is recommended. This should include PFAS target analysis, total oxidizable precursor (TOP) assays, and total organic fluorine (TOF) measurements. Additionally, comparisons of surface deposition estimates derived from diverse data sources emphasize the critical need for thorough PFAS decontamination before the implementation of fluorine-free replacement foams. Environmental Implication Per- and polyfluoroalkyl substances (PFAS) are pollutants of significant concern. Studies have linked PFAS exposure to a range of adverse health outcomes, including developmental, reproductive, hepatic, and immunological effects, as well as tumorigenesis in animal studies. Firefighting foams is one of the largest contributors to PFAS in the environment. When transition to fluorine free firefighting foams, PFAS remains adsorbed to the PFAS-exposed equipment and contaminates the product intended to be fluorine free. Effective decontamination protocols are needed to reduce the PFAS-rebound to a minimum. This paper synthesis knowledge from different studies to find trends improving the cleaning.
This research was funded by the Swedish Contingency Agency (MSB) under agreement number 2352608