A cohort of fire protection researchers funded by SERDP and ESTCP have made significant strides in testing the performance of replacements for aqueous film forming foam and supporting the Department of Defense’s transition to fluorine-free firefighting foams.

By Tracy G. Mallard, Ed.D. and Laura Mack

The National Defense Authorization Act (NDAA) for Fiscal Year 2020 directed the Department of Defense (DoD) to phase out the shore-based use of fire-fighting foam containing per- and polyfluoroalkyl substances (PFAS) in excess of one part per billion. Researchers have been racing to develop, demonstrate, and validate suitable replacements that do not contain PFAS. Over the past few years, the Strategic Environmental Research and Development Program (SERDP) and the Environmental Security Technology Certification Program (ESTCP) have funded a suite of projects aimed at assessing the capabilities of commercially available PFAS-free firefighting foam formulations. These efforts have contributed to recent qualification of the first fluorine-free product approved for DoD use.

Earlier this year, DoD achieved a key milestone with the publication (January 2023) of a new military specification (MILSPEC) for fluorine-free firefighting foams (F3s), MIL-PRF-32725. The initial draft of the specification was developed by John Farley, Director of Fire Test Operations at the Naval Research Laboratory (NRL), and his team using data that was collected from SERDP and ESTCP projects analyzing AFFF replacements.

Jerry Back, a Senior Fire Protection Engineer at Jensen Hughes, led two of the ESTCP project teams that performed capabilities assessments of commercially available PFAS-free formulations and informed the development of the new MILSPEC. He has spent 40 years in the fire protection industry and committed his last six years of work to evaluating PFAS-free firefighting foams.

“I started my career testing AFFF, and I’m ending my career trying to replace it,” Mr. Back said.

In 2017, the commercial industry began to search for fluorine-free firefighting foams, and Mr. Back conducted a study for the National Fire Protection Association to assess their capabilities and effectiveness. Replacing DoD AFFF products proved difficult because AFFF is highly effective in extinguishing flammable liquid fires at rapid speed and replacements had to meet the military’s safety requirements.

Mr. Back and Mr. Farley worked with other researchers to identify the leading AFFF alternatives and provide data for developing the new MILSPEC that will help standardize production of, and provide conformance test requirements for, commercially available F3s for use at DoD military installations. The project team supported DoD efforts to conduct a literature review and down select commercial replacements for AFFF that were suitable for DoD firefighting needs. After they narrowed the search to the top five replacement products, they conducted extensive tests and evaluation to understand their capabilities and performance.

The Naval Sea Systems Command (NAVSEA) then managed the formal development and publication of the MILSPEC, with Thomas Ruffini serving as the lead engineer for spec development. As standard for the development of military specifications, government, academia, and industry provided a broad technical review, including stakeholders from other federal agencies, state governments, research scientists, and the firefighting industry organizations. In a recent webinar, Mr. Ruffini explained how the new MILSPEC is a huge step forward in transitioning to fluorine-free foam formulations.

"If the criteria aren’t published yet, then we don't know what we're testing to,” he said. “We crossed that milestone and started to receive applications from manufacturers [to qualify their products].”

NAVSEA is the qualifying authority of this MILSPEC, so they are currently receiving and reviewing applications from manufacturers. Once a manufacturer’s application is approved, the candidate concentrate undergoes various tests and evaluations, such as health hazard and environmental toxicity assessments and fire performance evaluations. The final reports will be sent to NAVSEA for review and final approval for qualification. Approved products are then added to a Qualified Products List.

The fire extinguishing capabilities of F3s are somewhat less in comparison to MILSPEC AFFF, but a hand-full of the leading F3 products demonstrated adequate capabilities during testing and are now undergoing the process to be approved under the new F3 MILSPEC. AFFF was highly effective largely due to how rapidly it was able to extinguish fires. With new F3s, more finesse, and thus training, is required to extinguish fires. During the final phase of one ESTCP project, the team demonstrated large-scale fire tests at Naval Air Weapons Station China Lake to learn how to apply these agents to fires effectively and develop enough information that they can socialize to firefighters who will use the new formulations. F3s will continue to be evaluated and improved; SERDP and ESTCP are funding projects focused on advancing the state of science further for these foams. As knowledge evolves, the current military specification will also be revised.

"We intend to mature the specification over time,” Mr. Ruffini said. “We believe that industry will continue to improve the firefighting performance of the fluorine-free agents.”

The first F3 product was qualified by NAVSEA and listed on the Qualified Products List in September 2023. For more information, view the DoD PFAS Task Force announcement



The Strategic Environmental Research and Development Program (SERDP) and the Environmental Security Technology Certification Program (ESTCP) harness the latest science and technology to improve the Department of Defense’s environmental performance, reduce costs, and enhance and sustain mission capabilities. The programs respond to energy and environmental technology requirements across the military services. SERDP and ESTCP are independent DoD programs managed jointly to coordinate the full spectrum of research and development efforts, from the laboratory to field demonstration and validation. For more information, visit https://serdp-estcp.mil. Follow us on Twitter, Facebook, and LinkedIn.