Read the ISO 22241 Specifications for AdBlue®
Aqueous Urea Solution 32 Diesel Engine Fluid, more simply AUS 32 DEF, or better yet AdBlue® is manufactured to meet ISO 22241 standards in order to be compliant to be used in modern diesel engines.
AdBlue® is a registered trademark of the German Association of the Automobile Industry (VDA), our guide explains more about the emissions-reducing fluid.
ISO 22241 Specifications: Physical and chemical properties of AdBlue®
In order to be used in Euro 6 diesel engines, AdBlue® needs to meet the BS ISO 22241 specifications, which it does by having the required physical properties and chemical properties. The table below illustrates the properties AdBlue® needs to have.
| Property | Units | Specification | Test Method |
| Urea content | % (m/m) | 31.8, 33.2 | ISO 22241-2 Annex B ISO 22241-2 Annex C |
| Density @ 20ºC | g/cm3 | 1.0870, 1.0930 | ISO 12185 |
| Refractive Index 20ºC | – | 1.3814, 1.3843 | ISO 22241-2 Annex C |
| Alkalinity (NH3) | % | ≤0.2 | ISO 22241-2 Annex D |
| Biuret | % | ≤0.3 | ISO 22241-2 Annex E |
| Aldehydes | mg/kg | ≤5 | ISO 22241-2 Annex F |
| Insoluble Matter | mg/kg | ≤20 | ISO 22241-2 Annex G |
| Phosphate (en PO43-) | mg/kg | ≤0.5 | ISO 22241-2 Annex H |
| Calcium | mg/kg | ≤0.5 | ISO 22241-2 Annex I |
| Iron | mg/kg | ≤0.5 | ISO 22241-2 Annex I |
| Copper | mg/kg | ≤0.2 | ISO 22241-2 Annex I |
| Zinc | mg/kg | ≤0.2 | ISO 22241-2 Annex I |
| Chromium | mg/kg | ≤0.2 | ISO 22241-2 Annex I |
| Nickel | mg/kg | ≤0.2 | ISO 22241-2 Annex I |
| Magensium | mg/kg | ≤0.5 | ISO 22241-2 Annex I |
| Sodium | mg/kg | ≤0.5 | ISO 22241-2 Annex I |
| Potassium | mg/kg | ≤0.5 | ISO 22241-2 Annex I |
| Aluminium | mg/kg | ≤0.5 | ISO 22241-2 Annex I |
Download the AdBlue® Spec PDF here. All DEF supplied by Crown Oil meets the required standards.
If you have any other questions about AdBlue® or are looking for a supply from a trusted distributor, contact our Adblue® experts today on 0330 123 1444.
