DEN Completes Transition to Safer Firefighting Foam

DEN Completes Cleanup of 'Forever Chemicals' from Fleet of Aircraft Rescue and Fire-Fighting Vehicles

DENVER - May 12, 2025 - Denver International Airport (DEN), in partnership with the Denver Fire Department (DFD), has completed the cleanup and removal of per- and polyfluoroalkyl substances (PFAS) from its fleet of aircraft rescue and firefighting vehicles (ARFF) and filled each vehicle with fluorine-free foam (F3), transitioning away from aqueous film-forming foam (AFFF).

All 11 of DEN's ARFF vehicles have undergone rigorous rinsing cycles using a special cleaning technology, removing several hundred gallons of AFFF containing PFAS from each vehicle and achieving an average removal rate of over 98% of residual PFAS per vehicle.

Per- and polyfluoroalkyl substances are chemical components in aqueous film-forming foam, a firefighting foam that has been historically used due to its high effectiveness in extinguishing petroleum-based liquid fires. AFFF foam was formerly required by the FAA to be used at commercial airports dating back several decades.

DEN has worked proactively over the past several years to reduce and eliminate the use of AFFF foam, in early alignment with the Federal Aviation Administration's F3 Transition Plan released in May 2023. As soon as the FAA approved the first F3 product for airport use in September 2023, DEN was ready and authorized to begin its transition.

"As DEN continues its efforts to become the greenest airport in the world, it's our duty and responsibility as leaders in the aviation industry to ensure the safety of our fire personnel, employees, surrounding communities and the environment," DEN CEO Phil Washington said. "I'm proud to say DEN has taken proactive measures and is one of the first airports in Colorado to lead the way."

PFAS are found in many everyday items and are challenging to remove due to their strong resistance to chemical and biological degradation. DEN contracted with AECOM and TRS Group Inc. for the safe and effective removal of PFAS from its 11 AFFF trucks, using TRS's patented cleaning technology, PerfluorAd™. Modern cleaning methods including PerfluorAd™ use specialized cleaning agents, known as reagents, that can be co-solvents and surface scouring aids to enhance removal performance, compared to water-only rinsing methods.

DEN also completed the cleaning and removal of PFAS from nine vehicles used for structural fires using the enhanced rinsing method. DEN had previously conducted its first round of PFAS cleaning of these vehicles in 2021 using water-only rinsing methods, which were standard industry practice for removal of PFAS residuals at the time. This second cleaning ensures all firefighting vehicles in DEN's operation are free of PFAS to the maximum extent available.

Denver International Airport is one of the busiest airports in the world. DEN is the primary economic engine for the state of Colorado, generating more than $47.2 billion for the region annually. For more information visit www.FlyDenver.com, check us out on YouTube and Instagram, like us on Facebook and follow us on Twitter. Sign up for DEN's monthly newsletter Nonstop News.