The transition to fluorine-free foam requires more than changing the extinguishing agent. Portable extinguishers must combine chemistry, hardware and discharge performance into a complete, tested fire protection package.

For decades, Aqueous Film Forming Foam (AFFF) and Film Forming Fluoroprotein (FFFP) extinguishers have provided fire suppression, cooling and vapor control for flammable-liquid hazards. As restrictions on PFAS-containing products expand, fire protection professionals, facility managers and marine operators are being asked to replace legacy foam extinguishers without giving up those important performance characteristics.

That challenge is more complicated than simply replacing AFFF concentrate with a fluorine-free formulation.

Why Portable Foam Extinguishers Are Different

Properly applied foam does more than knock down flame. It can cool the fuel surface and create a foam blanket that helps reduce the release and ignition of combustible vapors, lowering the potential for reignition after visible flames are extinguished.

Recreating that performance with fluorine-free chemistry requires the extinguishing agent and hardware to work together as a matched assembly.

A stored-pressure portable extinguisher presents a unique challenge. Many fixed foam systems and firefighting handlines operate with relatively controlled flow rates and pressures. A typical 2.5-gallon portable foam extinguisher begins discharge at approximately 100 psi, but pressure continuously decreases as the extinguisher empties.

As pressure drops, discharge range, flow rate, aspiration, foam expansion and drain time can all change. Foam produced during the first portion of discharge may therefore behave differently from foam produced near the end.

Successful portable extinguisher design must account for those changing conditions throughout the entire discharge.

The Agent and Hardware Must Work Together

This is an important distinction when evaluating fluorine-free foam products.

A foam concentrate that performs well in one application cannot automatically be assumed to deliver the same fire performance when installed in a portable stored-pressure extinguisher. Agent formulation, cylinder pressure, siphon tube, valve, hose, nozzle and aspiration characteristics all influence the finished product.

For that reason, applicable portable-extinguisher standards evaluate the complete assembly and its ability to meet defined safety and Class A and Class B fire-performance requirements. In the United States and Canada, foam extinguishers are evaluated under applicable provisions of UL 8 and UL 711 and corresponding ULC standards.

For specifiers, the practical lesson is simple: testing of a foam concentrate or of other foam equipment is not the same as testing and listing the complete portable extinguisher.

Developing a Portable SFFF Solution

RELY spent more than three years developing and testing its P2.5-SFFF portable foam extinguisher. The development process evaluated combinations of fluorine-free foam formulations and extinguisher hardware to achieve consistent discharge characteristics and repeatable fire performance.

The resulting extinguisher uses a 2.5-gallon charge of Synthetic Fluorine-Free Foam (SFFF) formulated without PFAS or PFOS additives.

The P2.5-SFFF achieved a 2-A:10-B fire rating, an effective discharge range of approximately 10 to 25 feet and a discharge duration exceeding 60 seconds.

Those numbers provide useful performance benchmarks, but they also reinforce the broader point: portable fluorine-free foam performance depends on the complete extinguisher, not the agent alone.

Built for Demanding Environments

Replacing legacy foam technology also creates an opportunity to improve long-term durability and serviceability.

The RELY SFFF extinguisher uses a stainless-steel cylinder, stainless-steel siphon assembly, integrated hanger, large stainless-steel pull pin, full pressure-gauge protection, adjustable stainless-steel hose bands and an anodized aluminum air-aspirating nozzle.

A protective red coating is applied over the stainless-steel cylinder, and the extinguisher configuration successfully completed a 1,000-hour salt-spray corrosion exposure test associated with its USCG marine evaluation.

These construction features do not replace fire-performance testing, but they matter in chemical plants, transportation facilities, marine environments, heavy industry and other locations where corrosion, vibration and physical abuse can shorten equipment life.

Portable Foam and NFPA 10

Portable foam extinguishers continue to have defined applications within the 2026 edition of NFPA 10, Standard for Portable Fire Extinguishers.

The standard includes provisions allowing portable foam extinguishers to be used for certain extra-hazard Class B coverage, flammable-liquid hazards of appreciable depth and specific obstacle-fire hazards. NFPA 10 also addresses maintenance of premixed foam agents, with replacement based on the manufacturer’s recommendations and the applicable hydrostatic test interval.

The importance of these provisions is straightforward: the transition away from fluorinated foam does not eliminate the hazards where portable foam protection is useful. It increases the need to identify fluorine-free equipment that can perform those functions with appropriately tested and listed technology.

What to Look for When Replacing AFFF

Organizations evaluating replacements for legacy portable AFFF extinguishers should look beyond the words “fluorine-free” on a product description.

Start with the complete extinguisher. Has the assembled product been tested and listed for portable extinguisher use? What Class A and Class B fire ratings has it achieved? What are its discharge range and duration?

Also confirm that the foam agent is specifically approved for use in that extinguisher. Foam chemistry and hardware function as a matched pair, and recharge procedures should follow the manufacturer’s listed agent requirements.

Finally, consider the environment where the extinguisher will spend most of its service life. Corrosion resistance, vibration resistance and physical durability can be as important to long-term reliability as initial fire performance, especially in marine, industrial and outdoor applications.

A New Generation of Portable Foam Protection

The move away from AFFF represents a major change in portable fire protection, but it does not require organizations to abandon the benefits that made foam extinguishers valuable.

It does require a different approach.

Fluorine-free portable extinguishers must be engineered as complete assemblies in which agent chemistry, pressure, aspiration, discharge hardware and fire performance work together from the beginning of discharge through the end.

The RELY P2.5-SFFF was developed around that principle, providing an option for organizations transitioning away from legacy fluorinated portable foam extinguishers while maintaining the Class A and Class B performance expected from portable foam protection.

For additional information about the RELY SFFF extinguisher, its listings, fire testing and environmental durability testing, visit RELYFX.com.