BlueDEF® is a mixture of 32.5% high purity synthetic urea and 67.5% deionized water that is used in Selective Catalytic Reduction (SCR) systems on diesel engines. DEF is the primary ingredient used to help convert NOx to harmless nitrogen and water. BlueDEF® is stable, colorless, non-flammable, and is classified as minimum risk for transportation. BlueDEF® conforms to the ISO-22241-1 specification for DEF, is API registered and meets or exceeds OEM specifications. BlueDEF®’s exclusive triple-filtered formula ensures the highest product purity, and every batch is guaranteed pure.