FAQs About Diesel Exhaust Fluid Storage

As the demand for cleaner and more efficient vehicles continues to grow, products like Blue DEF have become a common subject of conversation among diesel engine owners.

These questions expand when talking about a bulk supply of DEF, particularly around storing and handling, as well as the benefits it offers. Whether you're a seasoned diesel engine enthusiast or a newcomer to the world of DEF, we’ve got the answers to the most frequently asked questions when it comes to this vital automotive fluid. 

What is Diesel Exhaust Fluid (DEF)?

Diesel exhaust fluid is one of the key elements of the selective catalytic reduction (SCR) process used by most medium and heavy-duty engine builders to meet EPA 2010 regulations. DEF is a non-toxic solution of 67.5 percent purified water and 32.5 percent ultra-pure automotive-grade urea. It is not a fuel or fuel additive; instead, DEF helps convert NOx into nitrogen gas and water vapor, two harmless and natural components of the air, when injected into the exhaust stream and passed over a catalyst. 

What is the Shelf Life of DEF?

When stored properly, the expected shelf life of DEF is approximately 1 year.

Is it OK to Store DEF in Extreme Temperature Areas?

Diesel exhaust fluid should be stored at temperatures between 12°F and 90°F. When stored in an environment where high temperatures occur, typically over 90°F, this can lead to reduced shelf life and the formation of ammonia in the DEF. If exposed to temperatures under 12°F, it will freeze; however, DEF that has frozen can still be used once it has thawed and has returned to a completely liquid state.

Will DEF Harm My Aluminum Container?

It is more important to consider what materials will harm the diesel exhaust fluid itself, rather than what materials the DEF can harm. DEF will not harm most materials, but the metal from aluminum tanks can leach into the DEF causing it to become contaminated.

What Materials Are Compatible With DEF?

Caution must be used when selecting an appropriate storage material for diesel exhaust fluid as there are many materials that will damage or contaminate it. DEF-approved stainless steel and poly are common materials used in DEF storage. DEF-approved storage containers available from Keller-Heartt include:

• DEF-Eco Package, 500 Gallon
• DEF-Eco Package, 800 Gallon
• DEF-Eco Package, 1,000 Gallon
• DEF-Eco Package, 1,500 Gallon
• DEF-Eco Package, 2,100 Gallon

Resource: Our Guide to Storing Your Lubricants Right

Is DEF a Hazardous Substance?

No. Especially in comparison to fluids such as diesel fuel and brake fluid, diesel exhaust fluid is far less hazardous. DEF is composed of naturally occurring materials and is biodegradable, non-toxic, and non-flammable. DEF is listed as a "non-hazardous" substance by DOT and UN standards and can be transported without an approved hazardous substance placard.

Is it Normal to See a Buildup of Chalky, White Material Around the DEF Storage Containers and Nozzles?

Yes, DEF can leave a chalky residue behind when the liquid evaporates. This is normal and can simply be cleaned off with deionized water.

Can I Mix DEF With Water to Stretch it Further?

No, you should never mix DEF with water or any other substance. DEF is a precisely engineered solution containing 32.5% high-purity urea and 67.5% deionized water. This specific composition is essential for the proper functioning of the SCR system in modern diesel engines.

How Does DEF Affect My Vehicle's Emissions and Performance?

DEF plays a crucial role in improving your vehicle's emissions and performance, especially in diesel engines equipped with SCR systems. When using a quality diesel exhaust fluid, it will help reduce emissions and associated particulate matter, comply with environmental regulations, enhance engine efficiency, and extend engine life.

If you are in need of diesel exhaust fluid or DEF storage equipment, Keller-Heartt can help. Keller-Heartt DEF products include:

• Blue DEF 55-Gallon Drum Premium Diesel Exhaust Fluid
• Blue DEF 275-Gallon Tote Premium Diesel Exhaust Fluid
• Blue DEF 330-Gallon Tote Premium Diesel Exhaust Fluid

Is Diesel Exhaust Fluid Available From the  Truegard^®  Line?

Yes. You can save money on 55-gallon drums by purchasing Truegard^® DEF directly from Keller-Heartt. It has exactly the ratio of high-purity urea to deionized water necessary for diesel engines. When buying from Keller-Heartt you don’t have to pay shipping fees. 

 You can browse our full collection of DEF storage and accessories here.