Aqueous film forming foam (AFFF) is a water based foam that was historically comprised of per- and polyfluoroalkyl substance (PFAS)-based surfactants. AFFF has been used by the military since the 1970s for fire suppression in ships, shore fixed systems, aircraft hangars and to extinguish liquid fuel fires in aircraft rescue and fire fighting (ARFF) vehicles. In FY20, Congress mandated that PFAS be eliminated from AFFF by FY25. In this technical session, presentations provided details on the performance of PFAS-free alternatives including research on recently-developed novel surfactants at the laboratory scale as well as commercially available products currently being tested comparatively in live-fire large scale tests. In addition, research on engineering solutions for improving foam quality were presented and the fundamental understanding of foam performance, with a focus on foam stability and the interaction of foams and bubbles with fuels, was highlighted.