PFAS Q&A: AFFF in the Aviation Industry
What is AFFF and how is it used?
Aqueous Film Forming Foam (AFFF) is a type of fire suppressant widely used in the aviation industry due to its effectiveness in combating aviation fuel-related fires. AFFF is a primary component of Aircraft Rescue and Firefighting (ARFF) vehicles, as well as fixed firefighting systems in aircraft hangars and jet fuel storage areas. When mixed with water, AFFF is dispersed as a foam that rapidly spreads over the surface and extinguishes flammable liquid fires.
What are the concerns associated with AFFF usage?
AFFF contains per- and polyfluoroalkyl substances (PFAS)—toxic chemicals that are commonly referred to as “forever chemicals” due to their persistence in the environment and difficulty associated with natural attenuation. While research associated with PFAS is still in its infancy, elevated concentrations of PFAS have been linked to increased cholesterol levels, increased risk of high blood pressure, hormone disruption, reproductive and developmental issues, and even certain types of cancer.
In April 2024, the United States Environmental Protection Agency (EPA) published drinking water standards for six individual PFAS compounds, ranging from 4 to 10 parts per trillion (ppt). However, many states have recently promulgated guidance promoting even lower concentrations. For example, the Minnesota Department of Health has adopted a drinking water guidance value of a certain PFAS compound measuring just 0.0079 ppt.
How is AFFF regulated?
Due to the human health and environmental hazards posed by PFAS-containing products, the EPA is requiring AFFF to be phased out. Several states have also implemented supplemental regulations and bans on AFFF use to mitigate the risks associated with PFAS contamination. Regulatory actions have led to the cessation of manufacturing AFFF products, and the use of AFFF is anticipated to be banned in July 2025. Many manufacturers have transitioned to the development of Fluorine-Free Foam (F3), an effective new fire suppressant that does not contain PFAS. As of February 2025, only three manufacturers of F3 products have been approved by the United States Department of Defense.
How do aircraft rescue and firefighting vehicles and fixed suppression systems transition to F3?
Transitioning from AFFF to F3 involves addressing the hazardous nature of AFFF and removing all potential residue within associated tanks, piping, and suppression components. Aircraft facilities can either completely remove and dispose of all components of fire suppression systems that have been in contact with AFFF or remediate those components and repurpose them within an F3 system. Due to the cost-prohibitive nature of replacing entire suppression systems, remediation is often the selected method.
Additionally, AFFF and associated tanks and apparatuses must be demolished and disposed of as hazardous wastes. During demolition, care must be employed to ensure AFFF is neither spilled nor comes into contact with workers. Fire suppression components—overhead sprinkler piping, deluge systems, hosing, etc.—that will become part of the F3 system must then be remediated, typically through a flushing program that removes residual AFFF. Following the removal of AFFF and remediation of a system, F3 tanks and piping can be installed to complete the transition.
How is transitioning from AFFF to F3 evaluated?
On December 31, 2024, the Federal Aviation Administration published CertAlert No. 24-11, which outlines output-based foam testing requirements for ARFF vehicles that have transitioned from AFFF to F3. Samples must be collected from each vehicle’s output of the roof and bumper turrets to ensure that the electronic and mechanical foam proportioning systems are functioning properly. The results of the output-based sampling must measure within 2.8% and 3.5% of input-based sampling results; if the output-based sampling results measure outside this range, additional remedial actions of the system are required.
What is Langan doing to support F3 transitions?
Langan developed a flushing technique for fire system components that reduces residual PFAS concentrations by up to 99.9%. Our technique utilizes only the water available at aviation facilities and does not require the addition of proprietary cleaning solutions. We also assist aviation facility owners with the development of AFFF management plans, disposal of AFFF- and PFAS-contaminated apparatuses, construction of spill containment systems, generation of comprehensive AFFF flushing programs, and installation of F3 systems. Langan recently helped a client successfully complete the AFFF-to-F3 transition of a cargo hangar located within the New York metropolitan area, resulting in the reduction of total PFAS concentrations by more than 100 times.
Ryan Hall has over six years of environmental experience across the Northeast United States. His work includes field sampling and testing programs, and subsurface soil and groundwater investigations on various industrial projects, including airports and airside facilities.