MyFuels AdBlue® is a high quality urea that is easy to use AdBlue is the registered trademark for AUS32, or Aqueous Urea Solution 32.5% that is used with the Selective Catalytic Reduction system (SCR) to reduce Nitrogen Oxide emissions from the exhaust of diesel vehicles. Nitrogen Oxide is a harmful gas that can cause respitory issues and damage to plant life. Putting AdBlue into your diesel vehicle can improve the air quality. Available in 5 and 10 Litre Drums Please always follow car manufacturers instructions when using AdBlue.