What is AdBlue

Combating Air Pollutants

With the very unsettling health and environmental repercussions of polluted air, there’s become a global push to lower hazardous diesel exhaust emissions.  The air pollutants that are found in diesel engine exhaust – particulate matter (PM), nitrogen oxides (NOₓ) unburnt hydrocarbons (HC) and carbon monoxide (CO) are some of the pollutants that developed countries have been trying to significantly decrease for decades.

The European Union (EU) who in the early 1990’s introduced the first initiative known as Euro 1 has lead the way in tightening emission controls throughout central and Western Europe.  Euro 1 at the time only affected truck engines and urban buses but they have since moved forward with five more initiatives to further decrease air pollutants; the latest with stricter on-board diagnostics requirements and new testing requirements as well – including off-cycle and in-use testing.

The Solution

In order for the EU to further implement its stringent emissions legislation it needed a solution to the problem.  The solution decided upon by the EU and manufacturers alike was to use a non-hazardous aqueous urea solution (AUS32) called AdBlue that is made up of 32.5% of high-quality urea and 67.5% deionized water.  

AdBlue when used in conjunction with the Selective Catalytic Reduction (SCR) system is released into the exhaust stream, the heat from the exhaust gas vaporizes the AdBlue which in turns forms ammonia and carbon dioxide (CO₂).  The nitrogen (NO) and nitrogen oxide (NO₂) in the exhaust gas reacts with the ammonia once they’ve passed through the catalyst and forms harmless nitrogen and water vapor that is released back into the atmosphere through the tailpipe.

AdBlue is manufactured to DIN standard 70070 and ISO 22241 standards.  To date, AdBlue is required by the majority of heavy duty diesel vehicles throughout the EU and is the preferred method for diesel exhaust treatment.  Adblue is the European term for Diesel Exhaust Fluid (DEF), which is what is utilized to lower hazardous emissions in North America.

Moving Forward

With the emission standards more stringent than ever now, the demand for AdBlue continues to rise as does the global demand for urea.  According research conducted by Integer Research, AdBlue consumption will top 6 billion liters by 2025 in Europe -further solidifying its importance in the fight against dangerous air pollutants. 

For more information on all things DEF, please see the following pages:




Phone: (435)723 5225 Maps & Directions