AdBlue nowadays is used in:
SCR technology is implemented to reduce harmful gases in diesel engines and meet the EURO4, EURO5, EURO6 and further EURO7 standards of emissions. These standards are required in many countries all over the World: whole Europe, USA, Africa, Australia, Singapore, Israel and many others.
When car/truck/van/or any other engine have implemented SCR technology, then the use of AdBlue is obligatory from legal point of view.
AdBlue in the catalyst is spread over the harmful gases (NOx – nitrogen oxide) and by chemical reaction transforms the harmful gas into harmless nitrogen and vapour – the components of atmosphere.