Firefighting Foam Transition:
What it Means for Airport Fuel Systems
Federal and state regulations on synthetic chemicals known as PFAS, found in military, industrial, and consumer goods, are restricting the sale and production of Aqueous Film-Forming Foams (AFFF), currently used at commercial airport facilities. These restrictions require the aviation industry to transition to fluorine-free foams (F3) at airport fuel storage facilities for the protection of human health and the environment. The transition to F3 will involve updates to infrastructure, including equipment, and other related fire protection system components.
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Contact us today to discuss your fire protection needs and discover how we can help you make a seamless transition.
Complying with all federal, state, and local regulations, as well as national codes can be complicated. That’s why Argus Consulting, in collaboration with an industry working group, has developed a standardized approach for the F3 transition at airport fuel storage facilities.
We'll walk through everything you need to know right here:
What is PFAS?
Per- and Polyfluoroalkyl Substances (PFAS) are a group of more than 9,000 synthetic chemicals. They can be found in products like cookware, cosmetics, utensils, food packaging, paints, and industrial applications like firefighting foam used to extinguish fuel-related fires. PFAS are considered “forever chemicals” because, by design, they don’t break down naturally in the environment and are toxic to animals and humans.
Exposure to PFAS can happen through water, food, and air, and that exposure is linked to health problems, including liver and kidney disease and cancer. According to a study by the U.S. Geological Survey, at least 45% of the nation’s tap water is contaminated by one or more types of PFAS.
New Federal and State Regulations for PFAS-Based Firefighting Foams
The federal government and many state agencies are moving forward with regulating the sale, production, and use of PFAS in various materials, including firefighting foam.
Current Airport Fuel Facility Fire Protection Systems
Firefighting foam systems protect a variety of aviation fuel facility assets. This includes storage tanks, truck loading and unloading areas, pump pads, and containment areas. Each system is unique, based on the configuration, age, and size of the fuel facility.
Until recently, AFFF (containing PFAS) had been the industry standard for fire protection systems and was approved for use in extinguishing fires involving hydrocarbons. Now, the emerging PFAS regulations will affect each airport fuel storage facility in different ways depending on the current configuration of the firefighting system infrastructure.
Fire protection systems for aviation fuel storage and distribution facilities vary in complexity and differ from those in other areas of an airport (for example, an aircraft maintenance hangar). Fire protection systems at aviation fuel storage facilities commonly include some combination of the components below:
Water Supply
Water can be stored on-site or
come from a municipal source.
Fire Pump
This provides the water pressure and flow rate needed in the event of a fire.
Foam Concentrate
Storage Tank
These tanks store the fire foam
concentrate (AFFF) until it’s
needed.
Aqueous Film
Forming Foam (AFFF)
Firefighting foam contains
fluorine and chemicals used
to extinguish flammable
liquids.
Foam Concentrate Piping and Proportioner
Foam concentrate piping carries AFFF or F3 from the foam supply tank to the proportioner(s). The proportioners are calibrated to mix a precise amount of foam concentrate into flowing water, creating the mixed foam.
Piping Network
This layout of connected pipes and valves connects water and firefighting foam supplies to their needed discharge points.
Tank Foam Chamber
Installed on storage tanks to properly distribute low-expansion foam onto the liquid surface of a fuel fire.
Fire Alarm Control Panel
The brain of the firefighting system, is capable of monitoring the current state of the system, reading signals from initiating devices (automatic or manual), and releasing flow for each system.
Fluorine-Free Foam (F3)
Following the approval of F3 products that comply with MIL-PRF-32725 in September 2023, the Federal Aviation Administration (FAA) immediately released a CertAlert allowing aircraft rescue and firefighting (ARFF) vehicles to use MIL-SPEC-approved F3. It’s worth noting that MIL-SPEC F3 is formulated for the use of firefighters on aircraft and airfield fires. Available MIL-SPEC F3 products have not yet been tested or listed to use for extinguishing fuel storage tank fires, commonly referred to as fuel in-depth fires. To protect these assets, commercial F3 products have been developed and are approved, at a minimum, by UL, NRTL, or FM Global. Additionally, commercial F3 foam concentrates from different manufacturers each have distinct chemical formulas and are not compatible to be mixed with one another.
AFFF vs F3: Difference in Fire Fighting
Fire requires four things to burn: heat, fuel, oxygen, and a chemical chain reaction. If you remove any one of these, the fire will be extinguished. AFFF and F3 foams help extinguish fires by targeting these elements in distinct ways.
AFFF forms a film barrier that suppresses fuel vapors even after the foam begins to break down. F3 foams don’t create this film barrier, so they rely on a consistent foam blanket to suppress vapors until the fuel cools down enough to prevent re-ignition.
During F3 use, the foam is evenly spread out and stays in place. In some cases, a higher concentration of F3 foam is needed to be as effective as AFFF.
Because F3 foam systems can differ from AFFF in terms of performance, the design requirements for supporting assets may also vary from AFFF. F3 designs require more customization because the density and pressure calculations must be specific to the F3 product used.
| AFFF | F3 | |
|---|---|---|
| Used for fire suppression | X | X |
| Used for sprinkler systems | X | |
| Creates a foam barrier | X | |
| Creates a constantly flowing foam blanket | X | |
| Historically, the industry standard at airport fueling facilities | X | |
| Concentrates are developed independently and are not compatible with one another | X | |
| Concentrates have a similar base and characteristics and are compatible with one another | X | |
| Systems must be custom-designed to fit the specific product | X |
AFFF to F3 Conversion
Given that each fuel facility was developed to fit the needs of the individual airport, the transition from AFFF to F3 will be just as unique. While there is no one-size-fits-all solution, the following factors will need to be evaluated:
Contact Contamination
Key components that have come in contact with the AFFF concentrate or the foam solution (AFFF concentrate and water) may need to be replaced, updated, or adequately cleaned. For example, atmospheric foam concentrate tanks are often demolished, whereas bladder tanks can be drained and the bladder replaced, allowing the tank shell to be reused.
Compatibility
F3 transition projects will need to assess whether the existing components are compatible with the new F3 product. NFPA 11 requires the proportioner, bladder tank, and specific end devices to be listed for use with the selected F3 product. In addition, F3 is not formulated for use in aboveground storage tanks equipped with subsurface foam injection systems. These must be converted to utilize surface tank foam chambers.
Disposal
There is no guarantee of complete removal of PFAS without replacing the entire fire protection system. Current disposal methods for AFFF concentrate, foam solution, and equipment exposed to AFFF include incineration, landfilling, and deep well injection (liquids only). Due to pending EPA regulations designating PFAS as hazardous waste under the Resource Conservation and Recovery Act (RCRA), disposal of AFFF concentrate, foam solution, and impacted solids at a Subtitle C hazardous waste disposal facility is recommended.
Conversion Implementation
The changing restrictions and codes involving the use of AFFF foam products make it challenging for fuel facility owners and operators to determine the correct course of action. Argus is prepared and proud to support our aviation partners as they remain environmentally proactive and adjust to the evolving landscape.
We have developed a sequence of steps for F3 conversion at airport fueling facilities. As more state and federal regulations are passed and implemented, the transition to new F3 concentrates becomes critical. Transition schedules may be impacted by delays in approvals, additional regulations and deadlines, and the availability of F3 and listed equipment components.
A typical F3 conversion plan will follow the following sequence:
- Risk Analysis
- Decision
- Concept
- Design/Permit
- Bid
- Material and Equipment Procurement
- Construction
Each aviation fuel facility is unique and will present its specific challenges. Argus completed multiple foam transition projects at facilities throughout North America.