The project's technical objective is to identify and develop per and polyfluoroalkyl substance (PFAS)-free firefighting formulations that meet the requirements of the revised MIL PRF 24385 and can enhance fire-suppression performance across multiple scenarios, including firefighting operations at extreme temperatures (as low as 32°F and up to 125°F) and a range of fuels including polar solvents, gasoline, or gasoline alcohol blends. The formulations developed in the effort will also be amenable for dilution with both fresh and saltwater. This Limited Scope Research work will be focused on using ionic liquid as solvents in the firefighting formulations. The project team will also evaluate the efficiency of 28-ft² pool firefighting performance and environmental impact of the foam formulations.

In this effort, ionic liquids will be used as solvents for the PFAS-free firefighting formulations. Ionic liquids could also be used with existing PFAS-free foams to enhance their firefighting capacity under extreme conditions. Alternate materials for firefighting applications are expected to meet the requirements of revised-MIL-F-24385F in terms of fire suppression performance to ensure personnel safety and viability of the system. Materials development will, therefore, include rigorous specification performance tests to capture the range of challenging fire situations, including testing at a wide range of temperatures (32-125°F), use of fresh and saltwater in "pre-mixed" formulations, and using various fuels including alcohol, gasoline, and their blends. In addition to evaluating ionic liquids as solvents, a new class of branched-alkyl chain PFAS-free surfactants will also be investigated in developing the firefighting foam composition.

PFAS-free foams products currently available as 3% or 6% concentrates sometimes exhibit high viscosity. The ionic liquid solvents developed in this effort can potentially solubilize the contents of the formulations efficiently and effectively reduce the viscosity of the concentrates. The branched-chain PFAS-free surfactants in ionic liquids can be used over a wide range of temperatures to quench variety of fuels including polar solvents, gasoline, or gasoline alcohol blends.