The Battelle/Air Force Civil Engineer Center (AFCEC)-Tyndall Air Force Base Team has tested more than 10 Fluorine-free foam (FFF) products using a conventional aspirated nozzle as well as an enhanced foam delivery system called compressed air foam, and has shown that no current FFF meets military specification (Mil-Spec) MIL-PRF-24385F, particularly the 30 seconds fire extinguishment time requirement. The objectives of this project are to (1) identify and prepare functional, point-of-use (POU) additives that can be added to, or co-delivered with, existing FFFs; (2) evaluate fire performance with and without the POU additives, relative to extinguishment and burnback times against the Mil-Spec; and (3) show feasibility of new and previously deployed nozzles for co-delivery of POU additives and FFFs.

The project team will identify and test POU additives and co-delivery nozzles to improve fire suppression performance of FFFs. The approach covers the following tasks: (1) identify and select up to eight POU additives; these are mostly commercial off-the-shelf (COTS) products but unexplored as additives for firefighting; (2) acquire/prepare new additives; (3) test additives in an existing, 45-in² fire test set-up; (4) test novel nozzles for co-delivery of FFF and additives in a 314-ft² fire set-up; and (5) conduct a preliminary sustainability analysis for the down-selected additives. In FY20, Battelle-funded an internal research and development project to address FFF formulations and identified two promising liquid-based additives, which underwent preliminary fire testing in collaboration with AFCEC under a Cooperative Research and Development Agreement. Additionally, in a parallel AFCEC/Battelle SERDP SEED project, additional promising siloxane-based additives were identified for improving fire performance. The project team has identified several potential POU additives based on a literature search and based on prior work conducted by AFCEC. Collectively, these additives utilize the three mechanisms of fighting fires (i.e., remove heat, remove oxygen, or disrupt the fire), only the first two of which are relied upon in the available FFFs.

The POU additives opens up a new avenue of Fluorine-elimination opportunities for Class B firefighting, as well as other types of fires, and benefits the DoD by identifying a solution that achieves supply chain resilience. None of the COTS or developmental FFFs are able to meet the Mil-Spec performance standards, although some are close to achieving that goal. The availability of additives that can be used by firefighters to meet the Mil-Spec fire performance specifications has the benefit of utilizing COTS or near-commercial FFFs without the need for time-consuming and expensive reformulation work by multiple vendors. The use of previously explored, as well as new, simple-design nozzles for co-delivery of additives will allow transition to existing ARFF trucks to help improve the fire performance of FFFs. Most importantly, the deployment of such POU additives does not require a deep knowledge of the PFF chemistries, which vary a great deal, and that vendors are reluctant to share due to potential intellectual property issues, nor is it impacted by lack of storage stability of FFF when combined with liquid/solid additives. (Anticipated Project Completion – 2025)