Safety Information and Updates

Diesel Exhaust Fluid (DEF) is an essential component of Selective Catalytic Reduction (SCR) systems used in modern diesel engines to reduce harmful nitrogen oxide (NOx) emissions. While DEF is non-toxic, non-flammable, and safe to handle, improper storage and use can compromise its effectiveness and potentially damage your vehicle’s emission system. Here are the best practices for the safe handling, storage, and use of DEF.

DEF is a solution made of 32.5% high-purity urea and 67.5% deionized water. It meets strict ISO 22241 standards to ensure quality and compatibility with SCR systems. It is important to keep DEF free of dirt, oil, fuel, and other substances. Even small contaminants can affect its performance and damage the SCR system. Use only dedicated DEF equipment for dispensing and storage to prevent contamination. DEF is not a fuel or fuel additive; it is injected into the exhaust stream to facilitate the chemical reaction that reduces NOx emissions.

Always use certified DEF that meets ISO 22241 standards. Off-spec or counterfeit DEF can cause system failures. DEF is corrosive to some metals, such as aluminum, copper, and zinc, so use materials like stainless steel or high-density polyethylene (HDPE) for storage and dispensing. You should store DEF in a cool, dry, and well-ventilated area. Check storage tanks, dispensing equipment, and DEF systems for leaks or damage regularly. While DEF is non-toxic, it can cause skin or eye irritation if mishandled. Use gloves and safety glasses when handling large quantities.

Ideal storage temperatures range from 12°F (-11°C) to 86°F (30°C). Exposure to extreme heat or freezing temperatures can degrade its quality. Should the DEF freeze in a truck when the truck is shut down, simply start the truck as normal, and the SCR heating system will quickly thaw the DEF, returning it to liquid form, and the vehicle will run as intended. DEF also degrades when exposed to direct sunlight. Use opaque or UV-resistant containers to protect it. DEF has a shelf life of about one year under optimal conditions.

Proper handling, storage, and use of DEF are crucial for maintaining its quality and ensuring the efficient operation of SCR systems. By following these best practices, you can help reduce emissions, avoid costly repairs, and ensure compliance with environmental regulations. If you have any questions about DEF, please reach out to our Sales Team 1-800-289-2875!

Since 2010, diesel vehicles equipped with “SCR” technology have been running cleaner, and friendlier to the environment thanks to Diesel Exhaust Fluid (DEF). DEF is a solution made up of approximately 67.5% purified water and 32.5% automotive grade urea. It is not flammable, non-toxic, and is not harmful to the environment. This key component of a diesel vehicle’s selective catalytic reduction (SCR) system is sprayed into the exhaust stream causing it to react with nitrogen oxides (NOx) resulting in the release of harmless nitrogen and water.

Though not dangerous to the environment, or to people handling DEF, there are several precautions users should be aware of in order to avoid damage to the vehicle’s SCR system:

• DEF has an extremely sensitive spec, and caution must be taken to ensure product integrity and performance.
• DEF must only be stored or dispensed from closed systems to avoid any possibility of contamination.
• DEF should only be stored or transported in dedicated DEF containers.
• Foreign matter of any kind (sold or liquid) should never be added to containers.
• When topping off, never use equipment like funnels, jugs, or diesel equipment to fill the vehicle, as any of these could result in contamination and degradation of the product.

In addition to the precautions listed above, users of DEF should be aware that while not “required” to wear protective clothing, many users may prefer to wear gloves to protect sensitive skin. Additionally, DEF is corrosive to copper and brass, so should only be used with materials listed in the ISO 22241 standard.

Because DEF is made predominantly of water, it can freeze. In fact, it will start freezing at around 12º F. Freezing will not affect the quality of DEF, and after thawing, it will perform as required. Should the DEF freeze in a truck when the truck is shut down, simply start the truck as normal, and the SCR heating system will quickly thaw the DEF, returning it to liquid form, and the vehicle will run as intended. If you have any questions about DEF, please reach out to our Sales Team 1-800-289-2875!

The information contained above was obtained from the Dennis K. Burke, Inc and Yara websites.