AdBlue® is the trade name for a crystal clear, synthetic produced 32,5% solution of ultrapure urea in demineralised water. This solution is needed for the exhaust aftertreatment in a SCR-catalyser. The aqueous urea solution is an environmentally friendly chemical for exhaust gas treatment. This is used in commercial vehicle (particularly by trucks and buses) so far.

AdBlue® is offered from filling station companies either in filling pumps or as canister. For useage of AdBlue® it is fitted an additional tank on the vehicle. The consumption from the urea-water-solution is about 4-6% of the normal fuel consumption. The urea technic within the exhaust gas treatment is necessary for Euro-4-Norm since 1. October 2006 and the tougher Euro-6-Norm is necessary since 1. January 2014.

The EU is to introduce Euro 4 effective October 1, 2006, Euro 5 effective January 1, 2010 and Euro 6 effective January 1, 2014.