Diesel Exhaust Fluid (DEF) is a urea-based fluid for Selective Catalytic Reduction (SCR), not a fuel additive. Use DEF conforming to ISO 22241, keep it in clean dedicated storage and transfer equipment, fill only the DEF tank, and investigate an SCR warning with the fault code and the vehicle OEM procedure.
Last technically reviewed: 23 July 2026.
DEF supplies the reductant used by an SCR system
On a vehicle designed with SCR, the system injects DEF into the exhaust stream to form ammonia. Inside the catalyst, ammonia reacts with nitrogen oxides (NOx) to produce nitrogen and water vapour. DEF never goes into the diesel tank, and its quality, dosing, warning diagnosis, and maintenance procedure must follow ISO 22241 and the OEM manual for each machine.
The main ingredient of Diesel Exhaust Fluid (DEF) is made from a mixture of pure urea and purified water. Urea is a chemical compound formed from the elements nitrogen and carbon dioxide. Pure urea is obtained through a chemical synthesis process involving ammonia and carbon dioxide.
Emissions rules determine which vehicles require SCR
Indonesia’s Minister of Environment and Forestry Regulation P.20/MENLHK/SETJEN/KUM.1/3/2017 establishes exhaust-emission limits for new vehicles in categories M, N, and O. Limits and test methods vary by category, mass, and engine type, so confirm SCR fitment and DEF requirements from the certification and OEM manual rather than inferring them from vehicle age alone.
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Why DEF quality and handling matter
- SCR system conformity. Equipment designed with SCR needs compliant DEF so dosing and catalyst operation can follow the OEM strategy.
- Contamination control. Diesel, oil, ordinary water, dust, or chemical residue in a tank or hose can make an otherwise traceable batch unsuitable.
- Fleet reliability. Batch records, consumption by unit, and fault codes help the team distinguish fluid, transfer-system, sensor, and vehicle-component problems.
For a mine fleet, calculate DEF demand from the SCR-equipped units actually operating, measured consumption, lead time, storage capacity, and the operating reserve. Those inputs support procurement better than a universal consumption percentage.
Conclusion
DEF is an emissions-control fluid for diesel equipment designed with SCR. Procurement should preserve ISO 22241 conformity, batch traceability, transfer cleanliness, and OEM requirements; maintenance decisions should use fault codes and vehicle data instead of assuming every warning originates with fluid quality.
DEF Handling Checklist for SCR Systems
DEF for an SCR vehicle is an emissions-control fluid, not a general urea solution. Use a product conforming to ISO 22241, prevent contamination, and follow the vehicle OEM’s requirements for storage, filling and fault diagnosis. Incorrect quality can disrupt SCR dosing and trigger system faults; never mix DEF with diesel, water or other chemicals.
| Check | How to verify | Action when it fails |
|---|---|---|
| Product identity | Confirm that the product documentation states ISO 22241 conformity and the container is clearly labelled | Quarantine material that cannot be traced; do not transfer it into a vehicle tank. |
| Transfer equipment | Use clean, closed, DEF-dedicated containers, hoses and funnels | Clean or replace equipment previously used for diesel, oil or another chemical. |
| Storage | Protect against contamination and follow the supplier/OEM storage conditions | Rotate stock and inspect package condition before filling. |
| Vehicle filling | Fill the DEF tank only and close it after filling | If the wrong tank is filled, stop and follow the OEM procedure before starting the engine. |
| SCR warning | Record the code, DEF consumption, vehicle condition and filling history | Diagnose with the workshop/OEM; do not clear a warning merely by adding fluid. |
For fleet and industrial-site requirements, Beta AdBlue is available for DEF applications. Beta’s team can connect packaging and transfer practice to fleet-consumption data through the contact page.
DEF Receiving and Traceability Record
Every DEF movement should be traceable from the received product to the vehicle or machine filled. The record below helps separate a product-quality concern, transfer contamination, a wrong-tank event and an SCR fault originating on the vehicle.
| Stage | Data to record | Decision point |
|---|---|---|
| Receiving | Supplier, product name, batch/lot, quantity, date, seal condition and ISO 22241 conformity document | Release to stock or quarantine damaged and untraceable packages. |
| Storage | Location, tank/package identity, opening date, closure condition and visual inspection | Keep stock closed; stop use when contamination is suspected. |
| Transfer | Dedicated DEF hose/pump identity, operator, date, source, destination and quantity | Confirm that equipment has not carried diesel, oil, water or another chemical. |
| Filling | Vehicle/machine number, odometer or operating hours, DEF quantity, operator and cap condition | Relate DEF use to vehicle duty and warning history. |
| SCR fault | Warning time, fault code, DEF level, last batch, symptoms and workshop/OEM action | Quarantine stock only when evidence points to the product; do not clear the warning without diagnosis. |
Retain samples or test DEF only under the company, supplier and OEM quality procedure; unsuitable sampling containers can contaminate the fluid. If a wrong fill is suspected, stop operation and follow the OEM procedure before starting the engine. Include this record when requesting product support from PT Beta Pramesti Asia.