What is Diesel Exhaust Fluid?


DEF is a 32.5 % solution of high-purity, synthetically manufactured urea in de-mineralized water. It is a safe-to-use fluid. Diesel Exhaust Fluid (DEF) is used in diesel engines with SCR systems to reduce emissions. As the world's largest DEF producer, Yara offers the security of supply and reliable quality DEF.

All diesel commercial vehicle equipped with SCR (Selective Catalytic Reduction) technology, since January 1st, 2010, comply with the emission standards imposed by the EPA Clean Air Act in North America. 

Yara's DEF product is certified according to ISO 22241 (ISO-22241-1, ISO-22241-2, ISO-22241-3). This international standard protects your vehicle from contamination which could cause serious damage. Using a urea solution of incorrect or low quality that does not follow these standards risks costly repairs.

Air1 is Yara’s brand of Diesel Exhaust Fluid. It is supplied across the US, so you are never far away from an Air1 North American distributor.

Practical tips
Practical tips

Practical tips

DEF is very easy to use and is a harmless substance. It is not a fuel, nor a fuel additive but a high purity urea solution that must be used in a dedicated tank on your vehicle, that should just be refilled as and when required. DEF is non-flammable and non-explosive. It is classified as a transportable fluid with minimal risk. If you ever spill DEF on your hands, simply wash them thoroughly with water. Learn more about how to use DEF:

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