By Alyssa Dunn, General Manager, Dyne Fire Protection Labs
Due to the environmental and toxicity concerns surrounding firefighting foam containing per- and poly-fluoroalkyl substances (PFAS), the fire protection industry is shifting to PFAS-free foam, or synthetic fluorine free foam (SFFF). However, the lack of PFAS in these products may have an impact on performance and shelf life, reinforcing the need for testing firefighting foam at least annually as recommended by NFPA 25, Inspection, Testing and Maintenance of Water-Based Fire Protection Systems.
PERFORMANCE
In the legacy fluorinated products, PFAS were added to give these products their film-forming properties. PFAS lower the surface and interfacial tension of the foam solution enough to allow for a film to spread across a wide variety of flammable liquids – protecting the fuel from reigniting. The film acts as a secondary layer of protection beyond the foam blanket. SFFF products do not contain PFAS and therefore do not have film-forming properties on such a wide variety of flammable liquids. Because of this, the foam blanket, measured as the expansion ratio, is crucial to the performance of SFFF products. NFPA 11,Standard for Low-, Medium- and High-Expansion Foam 2024 Edition A.4.3.1.1 states that:
“The testing conducted by the Fire Protection Research Foundation showed that expansion ratios of 7 to 10 were critical for SFFFs’ ability to extinguish fires.”
In other words, a higher expansion ratio may be required given SFFF products rely solely on the foam blanket for fire extinguishment. Most SFFF products also have a much longer drain time compared to the legacy fluorinated products. This increased drain time helps maintain the foam blanket longer.
SHELF LIFE
One of the concerns of PFAS is their bio-accumulating properties. Although this is a concern for the environment, the slow degradation of PFAS in fluorinated foams can result in a longer shelf life. Fluorinated foams stored properly can have shelf lives up to 25+ years. As a new technology without PFAS, there are concerns about the shelf life of SFFF products. Will they break down quickly or more easily? Testing these new products at least annually is critical in ensuring their performance properties are still sufficient.
WHY IS TESTING SO IMPORTANT?
With a higher expansion ratio requirement and an unproven, potentially shorter shelf time for fluorine free foams, there is less wiggle room for degradation or contamination. Given SFFF products are newer to the market, there is still more to be learned about how these products age over time. Testing these samples at least annually is important to ensure the performance properties have not degraded below the minimum requirements.
Questions? Contact us today by calling (800) 632-2304 or emailing lab@dyneusa.com.
