David Garris, firefighting foam agent & hardware product manager, at Johnson Controls explains how its new non-fluorinated foam has proven effective for large tank fire suppression
Alcohol-resistant aqueous film-forming foam (AR-AFFF) has been the standard for delivering rapid control and extinguishment of large, flammable liquid storage tank fires.
As foam technologies evolved, a new class of non-fluorinated products was introduced but struggled to deliver the performance of traditional AR-AFFFs – until now. Recent advancements have resulted in non-fluorinated foam solutions that perform similar to legacy foams.
The latest industry innovation is the new Thunderstorm WNF33A 3×3 foam concentrate, part of the Williams Fire & Hazard Control foam portfolio from Johnson Controls. It is the first product in its category to deliver control and extinguishment performance on large hydrocarbon tank fires that is comparable to its AR- AFFF predecessors. WNF33A is UL 162 listed as an alcohol-resistant synthetic fluorine-free foam (AR-SFFF) for use on hydrocarbon and polar solvent fires.
Putting it to the test
Multiple rounds of tank fire testing have demonstrated the firefighting performance of Thunderstorm WNF33A foam concentrate.
The foam was applied to fuel in-depth fires in a 42 ft (12.8 m) diameter tank. While NFPA 11 and UL 162 standards mandate a minimum foam application rate of 0.16 gpm/ft2 for these types of fires, the Thunderstorm WNF33A Foam was tested at half that application rate, 0.08 gpm/ft2 (3.26 lpm/m2), to challenge its fire suppression properties.
Following a 30-second pre-burn, firefighters were able to achieve control of the fires with a 3% Thunderstorm WNF33A foam solution in less than 2 minutes, with full extinguishment in under 5
minutes. For comparison, legacy Thunderstorm AR-AFFF products applied at the same application rate delivered control times in the range of 1 minute 45 seconds to 3 minutes, demonstrating the control performance of the new, non-fluorinated foam.
The Thunderstorm WNF33A Foam has a 25% drain time that exceeds one hour and provides for a long-lasting blanket with enhanced burnback resistance and vapour suppression, which aids in post-extinguishment hazard control of large flammable liquid tank fires – unlike many non-fluorinated firefighting foams on the market, Thunderstorm WNF33A Foam has been extensively tested for use in conjunction with dry chemical agents. It’s compatible with Purple-K and similar dry chemicals for dual-fighting applications.
Benefits for First Responders
Equally important as fire suppression performance is the ability to apply the foam concentrate using conventional firefighting equipment. Thunderstorm WNF33A foam concentrate produces robust, effective firefighting foam blankets at low expansion ratios – between 3:1 and 4:1 – verified by independent, third-party testing. This lower expansion range allows the application of Thunderstorm WNF33A foam with most standard discharge equipment, and for first responders provides a safer throw distance than air-aspirated foam.
Thunderstorm WNF33A Foam Concentrate was developed with a viscosity-shear curve very similar to the legacy Thunderstorm concentrates. Therefore, it may be effectively proportioned with the same type of equipment and setup as the legacy concentrates in most applications.
The concentrate is UL-listed for application with industry-standard nozzles, foam chambers, and sprinklers.
Eco-friendly firefighting foam
Thunderstorm WNF33A Foam Concentrate is a readily biodegradable, GreenScreen Certified Silver formulation. As a non-fluorinated foam concentrate, it does not contain intentionally added PFAS chemistry, and it is produced using equipment that has not handled PFAS chemistry.
Pursuing the highest level of performance
The transition from AR-AFFF to new, high-performing non-fluorinated foams for Class B firefighting demonstrates the industry’s adaptability to new customer demands and shifting regulatory guidelines. By employing the latest advancements in foam technology, such as Thunderstorm WNF33A concentrate, emergency response teams can be prepared to face the most challenging flammable liquid hazards with the greatest confidence.
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