In compliance with the new EU legislation (ref.Euro 4 and Euro 5) for the reduction of Nitrogen Oxide (NOx) emission in the environment, many manufacturers of vehicles have started providing their diesel fuel commercial vehicles with a new technology named SCR (Selective Catalytic Reduction) which requires that a blend of water and urea called “ADBLUE” is added to the exhaust gas. This water-based solution of pure urea (32,5% of purity) transforms Nitrogen Oxide in Nitrogen (N2) and Water (H2O) in gaseous state.