An important milestone has been reached in the effort to stop using fire suppression foams made with per- and polyfluoroalkyl substances (PFAS), known as forever chemicals.

In January 2023, a military specification (MIL-SPEC) was released for land-based applications of fluorine-free foam (F3), a new type of foam used to extinguish fires involving flammable and combustible liquids. This comes in the wake of the Department of Defense (DoD) requiring military bases to stop purchasing PFAS-based foams such as aqueous film forming foam (AFFF), by Oct. 1, 2023, and to eliminate the use altogether by Oct. 1, 2024.

What Has Changed?

The MIL-SPEC standard, MIL-PRF-32725, requires that no PFAS be intentionally added in the production of fire suppression foam and that PFAS levels not exceed 1 part per billion. The new MIL-SPEC standard takes into consideration the small unintentional amounts of PFAS that may seep into new F3 concentrations during manufacturing. Additionally, the DoD provides a list of specific PFAS chemicals in the specification that must not be detectable in new fire suppression foams.

The impact of this specification at military sites is still being analyzed. While the specification is in place, additional guidance is needed. The specification is only for the characteristics and conformance of the foam product and does not provide design guidance for systems at military facilities.

In addition to military installations, airports and aviation fueling facilities regulated by the Federal Aviation Administration (FAA) are being impacted by the specification. The FAA has provided guidance that F3 products meeting the new MIL-SPEC are allowed to be used at sites subject to FAA regulations. Previously, AFFF was the only fire suppression foam permitted for use at FAA-regulated sites.

With the ever-changing regulations around PFAS, facilities must determine whether the current foam suppression system requires immediate attention or if the transition can be delayed. Regulations vary in each jurisdiction regarding the penalties and requirements for these systems. Immediate changes may be required based on states and municipalities. However, some owners may see a different timeline available to them.

The main issue for facilities is required AFFF system maintenance and discharges of systems. The purchase of AFFF is becoming a challenge as certain jurisdictions, such as California, have banned the manufacture and purchase of it. As the availability of AFFF dwindles, some locations have opted to modify their existing systems so maintenance tests can be done with surrogate liquids and without discharging PFAS. However, this is a temporary fix. The true concern for a facility is an inadvertent discharge of the AFFF system. This is considered a PFAS release, and if it happens, the owner may not be able to replenish the AFFF.

How Should Facility Owners Move Forward?

Whether the move to an F3-based system needs to be happen now or in the future, there are potential challenges to consider. Switching from AFFF to F3 is not a one-for-one substitution. Due to the vast differences in F3 products between manufacturers, the process of transitioning from AFFF to F3 can be complex.

Because of the variation in physical properties and extinguishing capabilities, components used in F3 systems must be listed for use together. There are several options available to convert to F3 product-based systems from AFFF:

  • Undergo a full fire suppression system replacement. This option provides a high level of confidence PFAS will be removed from a given system.
  • Retrofit the fire suppression system. This often involves replacement of components and modification of the distribution piping. The distribution piping is flushed and the effluent disposed. Although this process will not guarantee a PFAS-free system, this option provides a more reasonable alternative to replacing the entire system.
  • Leave the existing system in place and use surrogate liquid testing. This can be done in areas where local regulations don’t require an immediate switch to F3, allowing facility operators time to plan and budget for the change.

Airports and aviation fueling facilities, military facilities and other operations that use AFFF to combat fires are facing uncertain times, with large changes looming on the horizon. Through it all, Burns & McDonnell advocates for a customized approach that involves working closely with local authorities and interested parties to provide a successful conversion in a timely fashion.

Understanding and adhering to PFAS regulations, as well as managing exposure and cleanup, is critical for airports, aviation fueling facilities and military bases that must regularly collaborate with regulatory agencies, insurance providers and other key interested parties. Burns & McDonnell can offer support for any projects involving AFFF conversion, PFAS and other pollutants.


To obtain a more individualized perspective on how regulations for PFAS and other pollutants will affect your operation, reach out to our knowledgeable professionals who can help you determine the steps needed to stay environmentally compliant.

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Kinsey Kurtenbach is a fire protection engineer experienced in designing low-expansion foam systems for aviation fuel facilities and commercial hangars.