Projects were sought to demonstrate and validate more environmentally sustainable (fluorine-free) firefighting aqueous film forming foams (AFFF) against the current performance requirements outlined in MIL-PRF-24385F and/or alternative foam delivery methods that enable the Department of Defense (DoD) to meet current performance requirements. The intent was to determine the maximum available performance using mature fluorine-free firefighting foams against the current military requirements.
Proposals could have also included evaluation of current test methodologies in MIL-PRF-24385 to determine minimum performance requirements that were needed to mitigate fires in operational environments or development of novel test methodologies for screening firefighting foams for liquid pool fires.
The materials and processes to be demonstrated/validated should have already been developed to at least a Technology Readiness Level (TRL) of 4, and the proposed project should have brought them to TRL 7 or higher. Alternative foams should have been production level materials rather than laboratory batch level samples. Projects must have demonstrated producibility, which is defined as the ability to be produced in the near term to meet the current DoD airfield or shipboard use requirement. Field testing in military relevant environments should have been included in the proposed project. Alternative foams must have been compatible with generally used storage equipment (e.g., polyethylene) and piping (steel, copper-nickel, bronze alloys), while providing comparable corrosion rates to current AFFF. Foams should have met requirements with fresh and salt water at multiple delivered concentrations.
Proposals should have included an assessment of the human health and environmental impacts of proposed ingredients, formulations, and byproducts. This should have expanded on commonly used aquatic toxicity, chemical oxygen demand and biodegradability testing required in the MIL-PRF- 24385. These proposals should have established a baseline lifecycle framework and identify the elements of a life cycle inventory that were already known, those that would be investigated during the course of the project, and those that were beyond the scope of the proposed work.
All projects were required to involve at least one DoD organization as a funded co-performer that was considered a stakeholder for the intended application. Proposals should have also indicated the involvement of other DoD stakeholders at least at the consultant level.
Funded projects will appear below as project overviews are posted to the website.
AFFF is a water-based foam used by the military since the 1970s for fire suppression in ships, shore fixed systems, aircraft hangers, and to extinguish liquid fuel fires. The DoD used AFFF mixtures containing significant quantities of perfluorooctane sulfonate (PFOS) and related perfluoroalkyl sulfonates until 2002, when production stopped; however, the DoD continued to use PFOS-containing AFFF stocks for some time after the halt in production. It is estimated that there are still over 500,000 gallons of PFOS-based AFFF in stock in the DoD inventory. The Air Force and Navy are the primary users for AFFF, with an estimated current stockpile of 423,000 and 97,000 gallons, respectively.
New AFFF formulations with telomer-based, short-chain fluorosurfactants (C6 or shorter) have been shown to have a reduced environmental impact. However, these materials still have the potential to persist in the environment or even to contain PFOS or PFOA. The current specification sets a maximum perfluorooctanoic acid (PFOA) and PFOS content for commercial foams. Current regulations for the short-chain compounds are less strict, but it is uncertain what the long-term environmental remediation requirements may be for these materials.
Worldwide regulation and effective bans of PFOA and PFOS led manufacturers to support a voluntary replacement program for the long-chain fluorosurfactants. Starting in 2006, the EPA and the Fire Fighting Foam Coalition (FFFC) initiated the voluntary global 2010/2015 PFOA Stewardship Program. This committed foam manufacturers to a 95% reduction in PFOA, PFOA precursors, and other long-chain polymers by 2010 and elimination of those chemicals in manufacturing emissions and finished foam by 2015. New formulations are made with telomerbased fluorosurfactants (six fluorinated carbons or fewer) that have been shown to more readily breakdown in the environment but may still have long term environmental impacts (e.g., persistence) or degrade to produce fluoroalkyl compounds of equal environmental concern. Industry, in coordination with the EPA, has conducted studies to determine the potential impact of the breakdown products of C6 foams, which have been found to be of low toxicity, low biopersistence, and not bioaccumulative, especially when compared to PFOS and PFOA.
At this time, AFFFs used by the military must contain fluorinated surfactants (and other compounds) per MIL-PRF-24385F. Industry has identified potential fluorine-free alternative foams; however, none of these technologies meet the performance required for military applications. The current MIL-PRF-24385 requires DoD to evaluate AFFF for foamability using specific test conditions (nozzles and feed rates) to meet specific application times to extinguishment and burn back time. Many fluorine-free alternatives can be used to extinguish pool fires, but do not meet the strict requirements outlined in MIL-PRF-24385. This test also includes generous safety factors to accommodate firefighters of varying experience and may not reflect actual operational conditions or application rates.
This problem is not unique to military operations. Civil aviation continues to use AFFF or fluorosurfactant-free fire suppression foams that do not meet the performance of AFFF. The FAA authorizes airport operators to only use AFFF products that meet the Mil-Spec as confirmed in 2011 in CertAlert No. 11-02, “Identifying Mil-Spec Aqueous Film Forming Foam (AFFF)”. Alternatives that meet or exceed current AFFF performance requirements without fluorosurfactants would dramatically reduce the environmental impact of fire suppression training and operations while maintaining the safety of personnel at crash sites or around liquid pool fires.