Synthetic Fluorine-Free Foam (SFFF/F3) Extinguishers
Synthetic Fluorine-Free Foam (SFFF), often referred to as F3, is the current Australian industry standard for portable foam extinguishers. This agent was developed to provide high-performance fire suppression for flammable liquids without the environmental persistence associated with legacy AFFF products.
The Transition from AFFF to SFFF
For decades, AFFF was the primary agent for Class B fires. However, due to the presence of PFAS—chemicals that do not break down in the environment—Australian regulations now mandate a transition to fluorine-free alternatives. Under the National PFAS Environmental Management Plan (NEMP), Fireshift and other service providers are moving toward SFFF to ensure environmental compliance and site safety.
Identification
SFFF extinguishers maintain the same identification standards as previous foam units under AS/NZS 1841.1:
- Main Body: Signal Red.
- Band: Blue band (Ultramarine) around the top of the cylinder.
- Labeling: Most modern units will explicitly state “Fluorine-Free” or “Eco-Foam” on the canister to distinguish them from older PFAS-containing stock.
Technical Fire Classes
SFFF is tested and rated for:
- Class B: Flammable liquids (hydrocarbons such as petrol, diesel, and oil).
- Class A: Carbonaceous fires (wood, paper, and plastic).
Note on Polar Solvents: Standard SFFF is designed for hydrocarbons. For fires involving alcohols, ketones, or esters (polar solvents), a specialized Alcohol-Resistant (AR-SFFF) variant is required. Fireshift can provide technical guidance on which variant is necessary for specific chemical risks.
Mechanism of Action
Unlike AFFF, which relies on a fluorinated film to seal fuel, SFFF uses a thick, high-stability foam blanket.
- Smothering: The dense synthetic foam structure creates a physical barrier that cuts off oxygen.
- Vapour Suppression: The foam prevents the release of flammable vapours from the liquid fuel surface.
- Cooling: High water content in the foam absorbs heat from the fuel, reducing the risk of re-ignition.
Performance and Compatibility
- Aspiration: SFFF requires “aspiration” (mixing with air) to be effective. The extinguishers are fitted with specialized nozzles to ensure the foam reaches the correct expansion ratio.
- AS 2444 Safety: Like all water-based agents, SFFF is electrically conductive. It must never be used on Class E electrical fires.
- System Flushing: When transitioning a site from AFFF to SFFF, AS 1851 guidelines suggest a thorough flushing of equipment to prevent PFAS cross-contamination.
Comparison: AFFF vs. SFFF (F3)
| Feature | AFFF (Legacy) | SFFF / F3 (Current) |
| Active Chemicals | Fluorinated Surfactants (PFAS) | Synthetic Hydrocarbon Surfactants |
| Environmental Impact | Persistent / Bio-accumulative | Biodegradable / Non-persistent |
| Suppression Method | Aqueous Film + Foam | Robust Foam Blanket |
| Regulatory Status | Phased out / Banned in many States | Australian Standard Compliant |