The primary objective of this project is to quantify the impact of specific additives to the performance of fluorine-free fire suppression foams under development at ADA Technologies (ADA). Ionic liquids, custom siloxanes, and nanoparticles, either commercial or developed by other SERDP/ESTCP performers, will be incorporated in ADA’s most promising formulations to demonstrate improved Class B fire suppression performance with the ultimate objective to meet the performance requirements of MIL-F24385F.

This project leverages recent SERDP and ESTCP investments in the field of fluorine-free (FF) foams to develop a new and improved formulation capable of meeting the MIL-SPEC requirements of the fluorinated aqueous film forming foam (AFFF). ADA Technologies is currently developing novel “green” surfactant mixtures that do not contain fluorine. Several have shown performance on par with commercial FF foams in small-scale fire tests with heptane and gasoline (1 and 5ft² pool fires) but do not yet match the performance of the MIL-SPEC fluorinated AFFF. In this project, ADA will selectively add ionic liquids, custom siloxanes, and nanoparticles to the currently best-performing ADA foam surfactant mixture at up to 2% weight fraction.

New foam concentrates (containing the targeted additives) will be tested on pool fires of surface area 1ft² and 5ft²), using heptane and gasoline as fuels. The best-performing formulation(s) would then be tested on the MIL-F-24385F 28ft² pan (and larger) in a subsequent phase. Fire test performance is a key technical risk in evaluating new agents, and the data to be acquired here is critical to evaluate the new formulations and their potential for full-scale military qualification in a potential follow on project. No data currently exists on the FF formulations, and therefore this project focuses on acquiring small-scale data first. The identification and testing of the best-performing mixtures will constitute the bulk of the technical activities. ADA has experience developing FF foams and testing them on small-scale pool fires to refine formulations. Key variables of interest in the fire tests will be recorded, in particular fire extinguishment time, thickness and robustness of the foam layer, and resistance to burn back. Aquatic toxicity of the selected foams will be evaluated as part of the project as well.

Fluorine-free AFFF achieving the required fire suppression MIL-SPEC performance standard has been an elusive goal for the Department of Defense (DoD) and industry as a whole for many years. Identifying such formulations would provide a viable, high-performance alternative to toxic perfluorooctane sulfonate/perfluorooctanoic acid-containing AFFF. In turn, this would end the use of these polluting foams, stopping the accumulation of toxins in organisms, soils and streams, especially in and around DoD bases.