what is ad blue

AdBlue, also known as diesel exhaust fluid (DEF), is a liquid used in vehicles with Selective Catalytic Reduction (SCR) technology to reduce harmful gases being released into the atmosphere. It is a 32.5% solution of high-purity, synthetically manufactured urea in de-mineralized water. AdBlue is automatically sprayed into a car’s exhaust system, where it decomposes into ammonia and CO2. When the NOx from the engine exhaust reacts inside the catalyst with the ammonia, the harmful NOx molecules in the exhaust are converted to harmless nitrogen and water, which are released from the tailpipe as steam. AdBlue is made of a mixture of urea and deionized water, and the urea is exceptionally pure and is of a higher grade than that used in cosmetics, glue, or fertilizers. AdBlue is commonly used in modern diesel cars to comply with stricter Euro 6 emissions standards that have been in effect since 2016. When buying AdBlue, it is important to check that it meets the correct specification, so look for the ISO 22241 number on the packaging.