AdBlue is an extremely pure, colorless liquid. This contains demineralized water and urea (32.5%). AdBlue is used in diesel engines and is also known outside Europe under the names DEF, ARLA 32 or AUS 32.
The main active component of AdBlue is ammonia. This is chemically formed by hydrolysis of automotive urea, which is the main raw material for AdBlue. Different types of urea are used for the production of fertilizers and many other applications.