Blue Leaf Diesel® Exhaust Fluid (DEF) chemically reduces nitrogen oxides (NOx) emissions from diesel-powered vehicles. Blue Leaf DEF shoud only be used in diesel vehicles which are equipped with SCR technology, and in accordance with vehicle manufacturer’s instructions. Blue Leaf is not to be added to the diesel fuel, but is to be dispensed in a separate DEF tank which is on the vehicle chasses. By chemically reacting with NOx inside a catalyst, Blue Leaf DEF breaks harmful NOx molecules into harmless nitrogen and water to meet the EPA Clean Air Act of 2010 NOx reduction requirements. Blue Leaf DEF is an aqueous solution containing urea. Blue Leaf® DEF meets ISO 22241 requirements. Blue Leaf® DEF is classed as non-hazardous.