The objective of this project is to refine Diethylenetriamine Polyphosphate (PNS) formulation and application to have an alternative to aqueous film forming foam (AFFF) for fuel fires that is ready for military specification testing within one year.
The most effective firefighting foams use perfluoro chemicals, which are inert to the radicals and ions of a flame. Since the foam is lighter than the liquid fuel, it creates a barrier between the flames and the fuel. A new approach is to spray a fine mist of PNS onto the flames. PNS is found to react with the ions and radicals in the flames and stop the chain reaction, suppressing the smoke and the fire. PNS is an extremely effective fire extinguishing agent for large gasoline fires. The project team can reliably extinguish a 28 ft2 gasoline fire in less than 10 seconds and a 50 ft2 gasoline fire in less than 20 seconds using a delivery rate of 1.6 gallons per minute. Times to extinguish diesel and heptane fires are even quicker. The fire extinguishing agent is delivered as a mist by an inexpensive pressure washer operating at 3,000 pounds per square inch.
The goals of this project are fourfold:
Fluorine containing firefighting foam is inert and not consumed by the fire. Because of the inherent stability of perflouro chemicals, they can bio accumulate and cause significant and well documented health hazards. In the new approach, most of the fine PNS mist is consumed by the fire and, due to its inherent effectiveness, less is used. Additionally, the fire extinguishing agent is similar in composition to fertilizers, so any PNS that escapes will react with the soil and break down, thus preventing bio accumulation. PNS has been tested by a company licensed by the Environmental Protection Agency and has been found to have low toxicity to the flathead minnow and non toxic for aqueous solutions of 50% or less. Additional benefits of PNS include effective smoke suppression and excellent visibility during application as well as heat dissipation. This PNS technology could be used in fires such in planes, ground equipment, and ships and very little is used as compared to foams.