Diesel Exhaust Fluid (AdBlue®/DEF) quality control testing per ISO 22241-1.

Diesel Exhaust Fluid (DEF) is often referred to as AdBlue® in Europe and other markets. AdBlue®/DEF is required by many modern diesel engine applications using selective catalytic reduction (SCR) technology to reduce the levels of oxides of nitrogen emitted by an exhaust system.

AdBlue®/DEF is a very pure 32.5% urea solution and in easy to use. Diesel engines with SCR (Selective Catalytic Reduction) technology are able to reduce emissions of nitrogen oxides from diesel vehicles. The Nitrogen Oxide produced by a diesel engine will be converted into nitrogen and steam and as a result, it will reduce NOx emissions of diesel vehicles to 85%. We see SCR (Selective Catalytic Reduction) technology, in agricultural and forestry machinery, buses, and cars with diesel engines, trains, and in the shipping industry.

SCR systems are part of the engine powertrain configuration, and contaminants or impurities in the AdBlue®/DEF could cause the SCR system to malfunction or fail. Thus, it is important to maintain quality standards as characterized in the ISO 22241-1 standard. Intertek provides a full range of prompt AdBlue®/DEF testing and analysis conforming to industry standards.

AdBlue®/DEF Quality

When testing against quality specifications it is essential that foreign materials do not come into contact with the solution.

Full specification testing is performed on a real-time turnaround to allow for fast efficient movement of product without impacting the deliverability of these products for your clients to the supply chain. The full specification service provided includes the following parameters.

AdBlue®/DEF testing:

The AdBlue® trademark is currently owned by the German Association of the Automobile Industry (VDA), who ensure quality standards are maintained in accordance with ISO 22241 specifications:

If it is necessary to add a tracer to AUS 32, it should be ensured that the quality of AUS 32 specified in this table is not impaired and that the tracer does not damage content and should not be compared directly to the minimum and maximum values for ures mass fraction (%).

aTarget value 32,5% (mass fraction)

bCalculated without subtracting nitrogen from ammonia

cReferee test method

Property Unit Limits Test Methods
Min. Max.
Urea contenta % (mass fraction) 31.8 33.2 ISO 22241-2:2019, Annex Bb
ISO 22241-2:2019, Annex Cb
Refractive Index (nD20) 1,381 4 1,384 3 ISO 22241-2:2019, Annex Cb
Alkalinity as NH3 % (mass fraction) 0,2 ISO 22241-2:2019, Annex D
Biuret % (mass fraction) 0,3 ISO 22241-2:2019, Annex E
Aldehydes mg/kg 5 ISO 22241-2:2019, Annex F
Insoluble matter mg/kg 20 ISO 22241-2:2019, Annex G
Phosphate (PO4) mg/kg 0,5 ISO 22241-2:2019, Annex H
ISO 22241-2:2019, Annex Ic
Aluminium mg/kg 0,5 ISO 22241-2:2019, Annex I
Calcium mg/kg 0,5
Chromium mg/kg 0,2
Copper mg/kg 0,2
Iron mg/kg 0,5
Potassium mg/kg 0,5
Magnesium mg/kg 0,5
Sodium mg/kg 0,5
Nickel mg/kg 0,2
Zinc mg/kg 0,2

ISO 22241-1 quality requirements, which determine the quality characteristics of the diesel exhaust fluid to ensure the proper performance of the SCR system. This is the main officially approved international standard. 

ISO 22241-2 specifies test methods required for determining the quality characteristics of the diesel exhaust fluid.

Intertek has a proven track record in delivering the results required at a fast turnaround time which is vital to our client's requirements in providing certified material to the market. Operating at a global level our AdBlue®/DEF testing laboratories offer accredited testing presented in easy-to-read, understandable reports.

We can also provide analytical testing of the raw materials from the manufacturing process as well as the final product and can offer various R&D services in regards to contamination issues and in the field problems which develop via our wide network of highly advanced laboratories. Diesel and other distillate fuels are common contaminants for AdBlue®/DEF tanks & systems and Intertek’s wide range of laboratories are also able to perform this testing should it be required.

Using our Intertek AdBlue®/DEF testing laboratories is easy and cost-effective. By using Intertek to routinely test and check the condition of AdBlue®/DEF material, you can be assured that your material is on specification from production to end-user. We can develop individual testing programs to meet your Total Quality Assurance needs and ensure sample collection, shipping, testing and, reporting is seamless, efficient, and cost-effective.

Intertek’s analysis expertise provides our clients with a multitude of benefits, with world-class testing facilities and global service coverage our independent and impartial specialists can truly satisfy your quality assurance needs with the precision, pace, and passion you desire.

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