Several per- and polyfluoroalkyl substance (PFAS)-free firefighting formulations (F3s) with unknown ecotoxicological characteristics are currently being developed and evaluated for their ability to meet current Department of Defense (DoD) performance requirements for training and emergency response, related to Class B fires. These products are intended for use as alternatives to aqueous film forming foams (AFFFs) containing perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), which were linked to accumulation in terrestrial plants and soil invertebrates with the potential for biomagnification in terrestrial food-webs. The main objectives of this project are to develop ecotoxicological data for candidate PFAS-free F3s via chronic toxicity test with soil invertebrates and terrestrial plants to support risk-based decision making.

This project involves toxicity tests that evaluate reproduction and growth with a variety of soil invertebrates and terrestrial plants.

Standardized toxicity tests will be conducted with ecologically relevant species using a natural soil expected to support high relative bioavailability. The test species were selected from International Organization for Standardization/Organization for Economic Co-operation and Development guidelines and were recommended in the Guide to Performing a Developmental Environment, Safety and Occupational Health Evaluation for collecting environment, safety, and occupational health (ESOH) data for materials used in DoD technologies in development. The goals of this research will be achieved by conducting the following activities: 

1. Determining the chronic toxicities of the candidate PFAS-free F3s to soil invertebrates exposed in soil with characteristics (low clay and organic matter content) expected to support high bioavailability for these products;
2. Determining the chronic toxicity of F3s to terrestrial plants in the same soil;
3. Developing the toxicity benchmark data established using standardized single-species toxicity tests with candidate F3s in the studies and ranking the order of the relative toxicity of each F3.

Ecotoxicological data developed in this project will fill the knowledge gaps regarding chronic toxicities of the candidate F3s to soil invertebrates and terrestrial plants. These data will be contrasted with the toxicity benchmarks developed for a legacy AFFF product in order to evaluate the relative environmental risks of exposure. This research will provide critical data to decision makers for use in ESOH evaluations of new technologies and the risk-based decisions, thus streamlining transition to acquisition programs. Ecotoxicological data developed in this project for all products will be transitioned through the Tri-Services Environmental Risk Assessment Work Group. (Anticipated Project Completion - 2024)