Foam types
AFFF (aqueous film-forming) historically used PFAS surfactants. AR-AFFF adds alcohol resistance. F3 / SFFF (Fluorine-Free Foam) replaces PFAS with hydrocarbon surfactants — now mandatory for new installations across the EU and many US states.
Proportioning
Concentrations: 1%, 3%, 6% (concentrate as % of total foam solution). Proportioning by balanced-pressure pump, around-the-pump, in-line eductor, or bladder tank. Accuracy ±10% per NFPA 11.
Application rates
Class B hydrocarbon spill, fixed system: 4.1 L/min/m² (0.10 gpm/ft²). Polar solvents: 6.5–9.8 L/min/m² with AR-AFFF/F3. Hangars: 6.5 L/min/m² over the entire deck (NFPA 409).
F3 phase-in
EU REACH restriction (Annex XVII, entry 68) restricts PFOA from July 2020; PFHxA from October 2024. Existing AFFF installations must transition; new installations must be F3. PFAS-laden foam concentrate is hazardous waste — disposal cost is now a material project line item.
References
- NFPA 11 (2021)
- EN 1568 series
- EU REACH Annex XVII
- APA
- FireTwin AI (2026). Foam systems & the AFFF → F3 phase-out. FireTwin AI. https://firetwin.eu/learn/foam-systems
- IEEE
- FireTwin AI, "Foam systems & the AFFF → F3 phase-out," FireTwin AI, 2026. [Online]. Available: https://firetwin.eu/learn/foam-systems