Is Purple K Dry Chem the preferred extinguishers to put on Airfield Fuel trucks? We see many that come with White BC and I'd like to recommend replacement at the next hydro.
Regulations do not specify a specific agent for this application. Purple K does have superior knock down and firefighting ability on flammable spill fires. Your recommendation to “upgrade” to a better extinguisher for the hazard is reasonable. Be sure to confirm that the Air Field allows dry chemical to be used around the airplanes as well.