This project leverages the continued development of ADA Technologies, Inc.'s (ADA) per- and polyfluoroalkyl substance (PFAS)-free (PF) foams for performance at extreme conditions. ADA is currently developing novel, “green” surfactant mixtures utilizing PF commercial off-the-shelf components (recent ESTCP project WP20-5381, SERDP project WP22-3089 and SERDP project WP21-3568). Recent testing has demonstrated ADA’s PF performance is comparable to commercial PF foams on small-scale fires (1ft², 5 ft² and 12.5 ft² pan fires) with both heptane and gasoline with up to 10% ethanol. Identifying a base PF foam formulation capable of performing at: (1) extreme temperatures, (2) on various fuels, and (3) with both salt and freshwater is critical to meeting the Department of Defense (DoD) objectives for phasing out bio-persistent fluorinated surfactants. Consequently, the primary objective of this one-year project is to identify the highest performing ADA foam available on these extreme performance conditions and adjust the formulation (if necessary) to meet the environmental requirements of the DoD while maintaining equivalent firefighting performance of existing aqueous film-forming foams (AFFF).

In the previous project (WP20-5381), ADA developed a number of successful PF firefighting foam formulations capable of extinguishing Class B fires on a small scale (1 ft² and 5 ft²). Testing was scaled up to 12.5 ft², and two formulations extinguished the gasoline fire in times comparable to AFFF. To date, ADA’s foams have been tested in optimal conditions: low wind, moderate temperatures, and with pure heptane or gasoline; any PF replacement foam must meet performance requirements for non-optimal firefighting scenarios as well. For example, firefighting operations can occur at a range of ambient temperatures, can involve fuels other than heptane and ethanol-free gasoline, and may need to utilize either salt or freshwater as a source for foam mixing. ADA will utilize formulations that have already proven successful under ideal conditions for further testing under extreme conditions. ADA will also make necessary revisions to existing formulations to optimize fire extinction performance.

PFAS-containing foams are extremely persistent chemicals linked to cancer, liver toxicity, and other health effects. Use of the currently-approved military AFFF is not desirable and should be eliminated as soon as viable qualified replacements are developed. PFAS-free firefighting foams capable of achieving the required fire suppression MIL-SPEC performance standard has been an elusive goal for the DoD and industry as a whole for many years. Identifying such formulations would provide a viable, high-performance alternative to biotoxic perfluorooctane sulfonic acid/perfluorooctanoic acid-containing AFFF. In turn, this would end the use of these polluting foams, stopping the accumulation of biotoxins into organisms, soils and streams, especially in and around DoD bases. Establishing reliable fire extinguishment performance under extreme conditions is also imperative to ensure the safety of DoD personnel and property.