A number of alternative per- and polyfluoroalkyl substance (PFAS)-free surfactant formulations are currently under development through SERDP-funded research, and commercially available PFAS-free foams are being tested under ESTCP to evaluate their ability to meet current Department of Defense (DoD) performance requirements. These formulations are intended for use as alternatives to aqueous film forming foam (AFFF) formulations containing fluorosurfactants that have demonstrated toxicity to fish and aquatic invertebrates and have the potential for biomagnification in aquatic food webs.
The main objectives of this project are to develop ecotoxicological data and determine the relative toxicities of these candidate AFFF-alternatives, as compared with AFFF formulations containing fluorosurfactants, by developing empirical data for chronic toxicity to fish and aquatic invertebrates. The specific technical objectives are:
- Determine the acute toxicities of the selected PFAS-free AFFF-alternatives to both freshwater and marine fish and aquatic invertebrates;
- Determine persistence of toxicity over time (i.e., to account for effects of aging, transformation and degradation in the environment);
- Determine the chronic toxicity to include sublethal endpoints, such as growth and reproduction to both freshwater and marine fish and aquatic invertebrates.
To understand potential toxicity of newly developed and novel PFAS-free firefighting foam formulations, the project team plans to evaluate the toxicity of three to five formulations using multiple taxa in both freshwater and estuarine/marine conditions. All toxicity test protocols will follow published and widely accepted standard toxicity testing from recognized organizations (e.g., US Environmental Protection Agency, American Society for Testing and Materials, Organization for Economic and Co-operative Development and/or International Organization for Standardization). Exposure during the bioassays will be monitored relative to initially spiked aqueous concentration by analysis of selected chemical features via targeted liquid chromatography tandem mass spectrometry (LC-MS/MS). Chemical features for LC-MS/MS analysis will be prioritized via non-targeted analyses of PFAS-free AFFF alternatives by LC-high resolution mass spectrometry.
It is critical to understand the potential risks (including exposure and hazard) that new formulations may pose to the environment. Results of this project will enable a holistic environmental assessment by DoD and regulatory stakeholders (e.g., state and federal) of candidate PFAS-free firefighting foams. Research data will directly provide: 1) relative hazard ranking among the candidate PFAS-free foams evaluated, including the potential for both acute lethality as well as longer term sublethal effects (growth and reproduction); and 2) an understanding of the persistence of toxicity over time to account for potential effects arising as a consequence of transformation and degradation under environmental conditions.