AdBlue liquid solution is made up of 32.5% urea and 67.5% de-ionised water. You may be wondering, where does the urea in AdBlue ic ammonia and carbon dioxide. The urea is then added to the de-ionised water to create AdBlue. This guarantees quality in accordance with very strict specifications contained in ISO 22241. AdBlue is a diesel exhaust fluid used in vehicles with Selective Catalytic Reduction (SCR) technology to reduce harmful gases being released into the atmosphere. AdBlue is a 32,5 % solution of high-purity, synthetically manufactured urea in de-mineralized water. It is a safe-to-use fluid. Parameter Minimum Maximum Unit Appearance Colourless Liquid with slight ammonia odour   Freezing point -11°C -11°C °C Boiling point 100°C 100°C °C Basicity 9 10 pH Flash point not applicable (non-flammable)   Water solubility 100  g/l Viscosity at 20°C 1.4 1.4 mPa.s Urea Content 31.8 33.2 % Density at 20°C 1.087 1.093 g/cm3 Refracting index at 20°C 1.3814 1.3843  Alkalinity as NH3  0.2 % Biuret  0.3 % Insolubles 20 mg/kg  20 mg/kg Calcium  0.5 mg/kg Iron  0.5 mg/kg Aluminium  0.5 mg/kg Magnesium  0.5 mg/kg Sodium  0.5 mg/kg Potassium  0.5 mg/kg Copper  0.2 mg/kg Zinc  0.2 mg/kg Chromium  0.2 mg/kg Nickel  0.2 mg/kg