The fire protection industry is in the middle of a generational shift.
After decades of relying on aqueous film-forming foams containing per- and polyfluoroalkyl substances, the PFAS compounds now widely recognized as environmental and health hazards, designers, facility operators and regulators are navigating a transition to synthetic fluorine-free foam alternatives.
For professionals responsible for Class B fire suppression systems in aviation, petrochemical, marine and industrial settings, the question is no longer whether to make the switch, but how to do it safely, effectively and in compliance with an evolving regulatory landscape.
PFAS are a class of thousands of synthetic chemicals characterized by strong carbon-fluorine bonds that make them extraordinarily persistent in the environment, hence the term forever chemicals.
Aqueous film-forming foams have used PFAS surfactants since the 1960s because those fluorinated compounds spread rapidly across hydrocarbon fuel surfaces, forming a vapor-suppressing film that is highly effective at extinguishing and preventing reignition of flammable liquid fires.
Mark Fessenden
The problem is bioaccumulation. PFAS compounds do not break down readily in natural systems.
They accumulate in soil, groundwater and living organisms and have been linked to immune system effects, thyroid disruption, developmental delays and certain cancers.
Contamination from firefighting foam training sites and emergency responses has created widespread environmental liabilities.
In response, the European Union began phasing out PFAS foams in 2011, and U.S. state-level bans, including legislation in California, New York, and Washington, are now accelerating the transition.
The US Department of Defense, historically the largest consumer of AFFF, has committed to discontinuing land-based use by 2024 and shipboard use by 2028.
Synthetic fluorine-free foams represent the industry’s primary alternative.
Unlike AFFF, which relies on perfluorinated surfactants, SFFF formulations use hydrocarbon-based surfactants to generate foam blankets that suppress vapor and cool fuel surfaces.
The goal is to deliver comparable fire suppression performance without the environmental persistence and toxicity profile of PFAS chemistry.
The central question for any fire protection professional evaluating SFFF is simple: does it work?
The research shows that the answer depends heavily on fuel type, application method, and specific foam formulation.
A 2020 blind study conducted by the Fire Protection Research Foundation tested five commercial SFFFs and one C6 AFFF baseline across multiple fuel scenarios, including heptane, gasoline and isopropyl alcohol.
The findings were instructive. SFFFs generally achieved fire control and extinction, but most required significantly higher application rates than the AFFF baseline, in some cases 1.5 to 3 times higher.
Mark Fessenden
Performance also varied by fuel class: several SFFFs matched AFFF on heptane but struggled with gasoline or polar solvents.
The study emphasized that aspiration ratio, the degree to which foam concentrate is aerated during discharge, had a major impact on effectiveness, with some SFFFs requiring expansion ratios of 7:1 or 8:1 to approximate AFFF performance at standard 3:1 ratios.
This variability has important implications for system design. SFFF cannot always be treated as a drop-in replacement for AFFF.
Equipment compatibility must be verified.
Discharge devices may need modification to achieve appropriate aspiration.
Application densities may need to be recalculated based on fuel-specific testing data.
And critically, foam concentrate must be matched to the hazard: a formulation that performs well on hydrocarbon fuels may be inadequate for alcohol-resistant applications involving polar solvents like methanol or acetone.
The environmental case for SFFF rests primarily on what it avoids: the persistence and bioaccumulation of PFAS.
One of the most operationally significant findings in recent SFFF research concerns residual contamination.
When facilities switch from AFFF to SFFF without thoroughly decontaminating existing foam delivery systems, PFAS compounds from the old foam can leach into the new concentrate, effectively re-fluorinating it.
A 2024 study published in Chemosphere examined aircraft rescue and firefighting vehicles at a major airport after transitioning to SFFF.
Despite system flushing, PFAS concentrations in discharged foam ranged from 0.3 to 1.6 grams per liter, levels high enough to reclassify the foam as fluorinated under emerging regulatory definitions.
The source was not the new SFFF concentrate, but residues trapped in hoses, proportioners, tanks and discharge devices that had decades of AFFF exposure.
The practical implication is clear: effective transition requires rigorous system decontamination or, in many cases, complete equipment replacement.
Guidance from the American Petroleum Institute and the New England Interstate Water Pollution Control Commission recommends multi-step cleaning protocols, including hot-water flushing with detergent, mechanical scrubbing of tank interiors and sampling to verify PFAS levels below detection thresholds before introducing SFFF.
For older systems with extensive PFAS contamination, the cost of proper decontamination can rival or exceed the cost of the foam itself.
The fire protection standards landscape is adapting, but not yet fully aligned with SFFF realities.
NFPA 11, the standard for low-, medium-, and high-expansion foam, now includes definitions and minimum performance criteria for fluorine-free foams, but fuel-specific listings remain inconsistent.
UL 162, the testing standard for foam concentrates, has been updated to accommodate SFFF, but many existing foam system approvals and insurance ratings were written around AFFF performance assumptions.
Designers must verify that proposed SFFF products carry appropriate third-party certifications for the specific fuel hazards present at their sites.
From a regulatory and risk management perspective, the trajectory is clear. PFAS restrictions will continue to tighten, both in the United States and globally.
Mark Fessenden
Facilities that delay transition planning risk non-compliance, increased insurance costs and environmental remediation liabilities. But the transition must be deliberate.
Selecting SFFF based solely on avoidance of PFAS, without validating fire performance for site-specific hazards or addressing system contamination, creates new risks.
The research consensus points toward a practical framework: conduct fuel-specific hazard analysis, verify foam compatibility through testing or manufacturer certification, decontaminate or replace foam delivery infrastructure, implement rigorous acceptance testing post-installation and maintain an ongoing review of evolving formulations and regulatory requirements.
SFFF technology is improving rapidly; formulations introduced today are measurably better than those available even five years ago, but fire protection is not a technology adoption race.
Mark Fessenden
It is a field where performance under the worst conditions matters more than convenience during the best ones.
