What to Do to Prevent DEF from Going Bad
- Susquehanna Sales
- Dec 13, 2022
- 2 min read
Updated: Oct 29, 2024
DEF, Diesel Exhaust Fluid, is a crucial solution that helps owners of diesel engines meet EPA’s emission standards. Thanks to the importance of DEF, many companies operating vehicles that require DEF have storage facilities on-site for easy access to DEF.
While storing DEF is great, improper DEF management can make it go bad, which can be disastrous for your engines. In this piece, we’ll tell you how to spot a bad DEF, its consequences, and what to do to ensure DEF doesn’t go bad.

Identifying Bad DEF
Looking at DEF is the easiest way to determine if it has gone bad. A good DEF is clear, without any colors. If your DEF looks cloudy or colored, then it’s highly likely that it’s not safe for use.
Adverse Effects of Bad DEF
If your DEF is colored or cloudy and you decide to use it anyway, your vehicle may begin to develop several issues:
Increased DEF consumption
Vehicle or equipment begins to malfunction. For instance, the engine may shut down.
The vehicle or equipment Selective Catalytic Reduction (SCR) system may malfunction or get damaged.
Vital components such as the diesel particulate filter or DEF dosing pump may get damaged.
Bad DEF leads to high fuel consumption and severely impairs engine performance. It also damages engine components, which will cost a lot to repair. The best way to avoid DEF problem is to prevent it in the first place.
How to Keep Your DEF in Top Shape
1. Note the Shelf Life
DEF has a shelf life of one year. Typically, the expiration date is one year after the date of manufacture.
2. Proper Storage
Properly storing DEF will keep out contamination and increase its shelf life. To do it, avoid using aluminum containers, as they can react with DEF. It’s best to use materials made of stainless steel and polypropylene materials. Also, date and label every container.
3. Keep an Eye on the Temperature
DEF is largely composed of water. So it can withstand cold temperatures. On the other hand, heat and direct sunlight can cause DEF to degrade. So store DEF indoors or in a well-shaded area.
4. Safe Dispensing
Ensure that DEF containers and dispensing nozzles are clean to prevent contamination. Also, make sure to dispense DEF directly from the storage container into your vehicle or equipment. Transferring into a container or using a funnel can contaminate DEF.
5. Assign a Supervisor
Assign someone to oversee everything concerning your DEF. The person will be responsible for making sure DEF is stored in the right container and conditions. A DEF supervisor will also remind others about DEF best practices, helping to avoid short and long-term DEF problems.
6. Partner with a Reputable DEF Distributor
To be certain you’re getting high-quality DEF, it’s a great idea to work with a reliable and trusted DEF distributor like Susquehanna Sales & Services. We have the capacity to deliver DEF directly into your vehicles or your bulk tank on a schedule that works best for you. Partner with us today.