What DEF Isn't...(Part 2)
DEF is not… blue.
Many companies that manufacture DEF or DEF handling equipment use the medium-blue color to distinguish their products for use with DEF, but the fluid itself is clear.
DEF is not… something you can blend on your own.
As mentioned in Part 1 of this series, DEF is a precise mix of highly pure, automotive grade urea and de-ionized water. We would be remised if we did not dispel rumors that it can be blended with agricultural urea. DEF that was manufactured in accordance with the ISO 22241 Standard will be labeled with an API Diesel Exhaust Fluid Certification mark.
DEF is not… a fuel additive.
Machinery equipped with an SCR system will have a separate fill port for DEF, which is often located near the fuel fill port and has a smaller opening. There have been occasions where someone has mistakenly put DEF in their fuel tank. In such instances, do not start the engine and contact your service professional to prevent damage to the fuel system.
DEF is not… used exclusively in the United States.
It’s known by different names in different parts of the world: Aqueous Urea Solution (AUS32) globally, AdBlue® in non-North American regions, and ARLA 32 in Brazil.
DEF is not… damaged by freezing.
The chemical properties of DEF are not altered by freezing. If you have fluid that is frozen, allow it to naturally thaw before use. DEF handling equipment, on the other hand, can be damaged when the fluid expands, so take precautions to prevent DEF from freezing inside fully-filled tanks and pumping systems.
DEF is not… going to last forever.
On average, DEF has a shelf life of 18 months. Shelf life is directly related to ambient storage temperature. In northern climates it can last up to 36 months and in southern climates the shelf life can be reduced to less than a year. You can find more detail about shelf life in the guide below.
DEF is not… able to be handled like other fuels and fluids.
You can’t put DEF in any old jug, tote, or pump that you may have lying around. It’s imperative that DEF is only stored, transported and dispensed in systems that are manufactured and sterilized in compliance with the ISO 22241 standard. In off-road environments, closed systems are best.