TDA Research Inc. (TDA) has developed a per- and polyfluoroalkyl substance (PFAS)-free foam (F3) from the ground up and has invented novel nanoparticles and surfactants to address some of the deficiencies found in current F3 formulations. The project team anticipates that these proprietary components would also improve other F3 formulations currently on the market. No commercial off the shelf (COTS) F3s have passed MIL-PRF-24385F, which requires fire extinguishment within 30 seconds and > 360 seconds of burn back suppression. TDA has developed two additives that can improve the performance of existing F3 foams—an anionic surfactant and foam-stabilizing nanoparticles. This project suggests that the addition of TDA’s anionic siloxane surfactant would stabilize existing COTS F3 foams from other manufacturers and lower the surface tension of their foams, improving their spreadability and extinguishment time. TDA’s nanoparticles would provide long term foam stability and form a strong foam blanket to help the COTS F3 suppress burn back for a longer time. The project team has also discovered a synergistic effect between commercially available surfactants and additives and the proprietary components in TDA’s F3 formulation. Therefore, the project team will prepare an additive “package” for COTS F3s, composed of both commercial and proprietary components in TDA’s F3 that have been shown to work synergistically to extinguish fires and prevent burn back.

TDA has developed a novel F3 formulation containing proprietary components that: 1) improve the flow of foam over the burning hydrocarbon fuels to rapidly extinguish the fire, and 2) reduce fuel transport through the foam. In this project, TDA will evaluate the addition of components in the F3 formulation to commercial F3s with the goal of improving extinguishment time and suppressing burn back. Specifically, the project team will test the additives with products from five different major players in F3 foams-- National Foam (Universal F3 Green), ChemGuard (Ecoguard), Tempest (Ecopola), EnforcerOne (Firebull), and Angus Fire (Respondol ATF). Based on the data sheets of these products, the project team knows these products include a range of different surfactants (anionic, zwitterionic, hydrocarbon, etc.) and gums (xanthan, guar), and these will that interact differently with the additives. Including several F3 products in the study will allow the project team to prepare a broadly applicable additive package or set of additive packages. In addition to collecting data on the fire suppression performance, factors related to long-term storage of the additives (flammability, viscosity, reactivity, shelf life) will also be evaluated and compatibility with the commercial foam, foam delivery equipment and infrastructure. The project will culminate with demos of commercial foams incorporating the additives, carried out at Tyndall Air Force Base.

TDA’s objective is to develop and deploy chemical additives that can be added to mature and emerging PFAS-free fire suppressants in order to enhance their fire-suppression capabilities. No currently available PFAS-free formulation meets the stringent fire extinguishment requirements in MIL-PRF-24385F. Functional additives that improve performance of PFAS-free commercial firefighting foams will accelerate the rapid transition to PFAS-free foams within the Department of Defense.