Frequently Asked Questions

Here's what our customers are asking

Here you will find frequently asked questions from our customers on how to order a product, order processing, and security of information. If you can't find what you're looking for, please reach out to our team and someone will get back to you shortly. You can also buy products online by visting Brenntag Connect.

What is diesel exhaust fluid (DEF)

We're glad you asked. Diesel Exhaust Fluid (DEF) is a non-toxic, high purity solution comprised of 32.5% urea and 67.5% de-ionized water for specific use in Selective Catalytic Reduction (SCR) systems. Using this fluid in diesel-powered vehicles, such as trucks, buses, and tractors, helps to reduce the amount of nitrogen oxides (NOx) emitted into the air by 90%. It is not a fuel additive and must be filled into the dedicated Diesel Exhaust Fluid tank on your diesel vehicle.

Red White and Blue Parked Trucks Lined up at a Truck Stop in the wintertime in Utah

Why do I need DEF

Simply put, you need DEF to keep your trucks running. This is because many diesel engine manufacturers have chosen Selective Catalytic Reduction (SCR) technology to meet the 2010 EPA Emissions Standards. Diesel Exhaust Fluid is used in the SCR system for on-road diesel vehicles manufactured beginning in 2010. Without DEF, your diesel vehicles will not function. SCR and DEF are used to convert Nitrogen Oxide (NOx) into harmless Nitrogen and Water molecules. Nitrogen makes up about 78% of the air we breathe.

Click on the topics below to learn more about DEF

Handling, storing, and using DEF

In short, yes, DEF is affected by temperature. ISO22241 recommends Diesel Exhaust Fluid (DEF) should be stored in a cool, dry place. Ideal storage temperatures should be between 12°F (11°C) and 86°F (30°C). The reason for this recommendation is because DEF can lose its potency if stored above 86°F for prolonged periods of time. If you're worried about storage, we can assist you in developing equipment storage solutions to ensure your product is best preserved in all weather conditions. Have a few minutes to spare? Here are a couple interesting brief articles about Summer Storage and Handling DEF in Cold Climates.

Diesel Exhaust Fluid should be stored out of direct sunlight in a cool, dry and well-ventilated area. Ideal storage temperatures are between 12° F (11° C) and 86° F (30° C). Optimum storage facilities include garages, warehouses or storage systems recommended by equipment manufactures. If you have any questions regarding proper storage, contact us today .

The answer is "yes". Diesel Exhaust Fluid has unique properties making it crucial to use the proper equipment. DEF is stored and dispensed through dedicated containers and systems. We can assist you in developing equipment storage solutions to meet your specific needs.

No, Diesel Exhaust Fluid will remain unharmed if it freezes and thaws. The urea and water will not separate or lose its potency.

Diesel vehicles are equipped with heated tanks and supply lines designed to freeze and thaw with no performance issues.

Diesel Exhaust Fluid is not a diesel additive. Vehicles manufactured with Selective Catalytic Reduction (SCR) technology are designed with a separate urea tank to hold Diesel Exhaust Fluid. Do NOT mix DEF and diesel fuel as this can cause major problems. Read more about DEF in the Diesel Tank here.

If a non-DEF substance enters the Diesel Exhaust Fluid tank, the Selective Catalytic Reduction (SCR) system will recognize a substance other than DEF. The trucks indicator light will then turn on to notify the driver. Whether or not the vehicle requires servicing is dependent on the level of contamination. We recommend having this checked out right away.

There are a few fail-safes in place. The standard diesel fuel nozzles have a diameter of 22mm. Diesel Exhaust Fluid nozzles have been manufactured at 19mm to prevent standard nozzles from being placed into the DEF tank opening. The DEF tank is also easily recognizable due to its blue tank cap.

The amount of Diesel Exhaust Fluid your truck will use is dependent on the size of the truck's tank and dosing rate chosen by the vehicle manufacturer. DEF tanks range in size from approximately 6 to 30 gallons. You can use our interactive Diesel Exhaust Fluid usage calculator for pretty accurate results.

Refueling intervals will depend on the size of your tank. The Diesel Exhaust Fluid consumption rate is between 2-4% of the diesel fuel consumption. For example, for every 100 gallons of diesel fuel consumed, between 2-4 gallons of DEF will automatically be injected into the exhaust system. A typical diesel truck can go about 300 miles on one gallon of Diesel Exhaust Fluid.

A typical diesel truck could go about 300 miles on one gallon of Diesel Exhaust Fluid.

If your vehicle runs out of DEF, you will first experience performance degradation followed by the inability to start the vehicle.

Testing Diesel Exhaust Fluid can be done using a variety of methods. We recommend you take a few minutes to watch our 3 Easy Testing Methods video to learn about each method.

Diesel exhaust fluid safety

We're glad you're worried about safety as much as we are. Good news, Diesel Exhaust Fluid is classified as a non-hazardous material. However, it is corrosive to most metals. Stainless steel is the only metal used in manufacturing DEF pump equipment. More good news, Diesel Exhaust Fluid is not flammable as classified by WHMIS/OSHA criteria. In case of a fire, DEF containers may be extinguished with water. Read more about DEF handling in our DEF DO's and DON'Ts here.

Accidents happen. Small spills may be absorbed with a non-reactive absorbent and placed in suitable, covered and labeled containers. Prevent large spills from entering into waterways, sewers, basements, or confined areas. DEF can be harmful to concrete and masonry so clean it up as soon as possible. Never return spills back into the original containers for re-use.

You can find all the technical information you'll need here on Brenntag Connect .

Diesel exhaust fluid properties

Good question. Since urea is the active ingredient in Diesel Exhaust Fluid (DEF), it's important to understand what it is. Urea is created from synthetic ammonia and carbon dioxide. When subjected to high heat and pressure it can be produced as a liquid or a solid. Synthetic urea is used mainly in fertilizers, but is also used in plastics, animal feed, cleaning agents, and pharmaceutical applications. Urea producers supply two types of urea, automotive grade and agricultural grade. Automotive grade urea, unlike urea used in fertilizers, does not contain formaldehyde and must be used in the production of DEF. Formaldehyde and other impurities can cause damage to the catalyst in your Selective Catalytic Reduction (SCR) system .

Yes it does. Diesel Exhaust Fluid smells due to the ammonia content, but the odor is mild and harmless.

DEF is pretty heavy. One gallon of Diesel Exhaust Fluid weighs 9.08lbs.

Ensuring diesel exhaust fluid quality

Yes, quality of Diesel Exhaust Fluid is extremely important. High quality DEF will be produced and distributed by companies that have demonstrated their domestic expertise in production and distribution. Qualified companies will bear the American Petroleum Institute (API) Certified symbol. Check out why quality matters with Diesel Exhaust Fluid here.

The American Petroleum Institute (API) Certification program authorizes Diesel Exhaust Fluid distributors that meet specified requirements to use the API Certified symbol. This mark identifies which distributors meet the ISO performance requirements. This program provides the following benefits to consumers: provides rigorous monitoring of fluids in the marketplace, tests licensed fluids to ensure they meet program requirements, identifies brands that meet diesel engine manufacturer requirements and helps reduce NOx emissions.

Technology associated with DEF

Selective Catalytic Reduction (SCR) is an exhaust after treatment system that injects a small amount of a chemical called Diesel Exhaust Fluid (DEF) into the exhaust. DEF is mixed with exhaust in the presence of a catalyst turning NOx (oxides of nitrogen - a harmful pollutant that contributes to smog and acid rain) into harmless nitrogen and water vapor. This technology has the ability to reduce NOx to near zero levels while also providing your fleet with a 3-5% savings on diesel fuel usage.

An SCR system is designed to permit nitrogen oxide (NOx) reduction reactions to take place in an oxidizing atmosphere. It is called "selective" because it reduces levels of NOx using ammonia as a reluctant within a catalyst system. The reducing agent reacts with NOx to convert the pollutants into nitrogen, water and tiny amounts of carbon dioxide (CO2) - natural elements common to the air we breathe every day. The reluctant source is usually automotive-grade urea, otherwise known as Diesel Exhaust Fluid, which can be rapidly hydrolyzed to produce the oxidizing ammonia in the exhaust stream. SCR technology alone can achieve NOx reductions in excess of 90%. Pretty cool, huh?

Selective Catalytic Reduction (SCR) is an exhaust after treatment system that injects a small amount of a chemical called Diesel Exhaust Fluid (DEF) into the exhaust. DEF is mixed with exhaust in the presence of a catalyst turning NOx (oxides of nitrogen - a harmful pollutant that contributes to smog and acid rain) into harmless nitrogen and water vapor. Exhaust Gas Recirculation (EGR) is another way to reduce NOx formation.

In an EGR system, engine exhaust is recycled back through the engine to dilute the oxygen. Almost all engine manufacturers' use a form of EGR, as it takes both EGR and SCR to achieve near-zero NOx emissions.

SCR technology has been implemented by several leading original truck producers (also referred to as OEM's) such as: Peterbilt, Kenworth, Freightliner, Ford, Daimler, Hino, Volvo and Mack Trucks North America.

How to acquire DEF

Fill out this form and we'll put you in touch with your representative. You can also view and buy products online by visting Brenntag Connect .

We are committed to safely and effectively supplying you with high quality UltraPure® Diesel Exhaust Fluid. View and buy DEF products online at Brenntag Connect .

Diesel Exhaust Fluid is priced differently across the country, much like diesel fuel. Factors affecting price include: ammonia, oil, and/or natural gas costs, package size and order quantity. If you are interested in purchasing DEF, please request a quote , call our toll free number at 1-877-363-5843 or email us at You can also view products online by visting Brenntag Connect .

We offer Diesel Exhaust Fluid in a variety of package sizes - 2.5 Gallon Jugs, 55 Gallons Drums, 330 Gallon Totes, mini-bulk, and bulk. If you're not sure what size you need, try our DEF usage calculator . If you still have questions, call our toll free number at 1-877-363-5843 or email us at View our package sizes online at Brenntag Connect .

We offer two different types of totes: one-way returnable and refillable. Returnable Diesel Exhaust Fluid totes can be returned and refilled as long as there has been no contamination. Refillable on-site totes can be left at your location and will be refilled by a Brenntag delivery truck.

Please complete this form to get information on becoming a Diesel Exhaust Fluid (DEF) distributor.

Give us a call at 1-877-363-5843 so we can help you out.

Complete the short form so we can get you in contact with your representative.

Freight trucks

Let us help with your DEF questions

Contact us today to find out more about our specialty chemical product line, or if you have a question about our DEF products. Our experts can help you with any of your DEF needs or questions you may have.

We service all DEF markets including agriculture, automotive, off road applications, and trucking since 2009. Our DEF comes in a variety of package sizing to fit your needs.

Learn more about our DEF services

Stay connected in the DEF industry

Sign up for the latest information on our DEF ingredient solutions. Choose to receive communications on industry updates, supplier and product information, and trade shows and events.

Speak to a team member

Contact us today to find out more about our product offerings, to ask us any questions, or to let us know how we can assist you with a specific application.