Prime Guard Diesel Exhaust Fluid (DEF) 1 Gallon — ISO 22241 Certified, Ready-to-Use

Designed to meet strict international purity and concentration criteria, Prime Guard DEF helps SCR-equipped diesel vehicles operate within EPA-compliant emissions parameters. This ready-to-use, formaldehyde-free solution is manufactured to ISO 22241, AUS 32 and DIN 70070 specifications and carries API certification, ensuring it matches the quality requirements demanded by modern diesel aftertreatment systems.

How does Prime Guard DEF fit into my vehicle's emissions system?

DEF is injected into the exhaust stream ahead of the SCR catalyst where it converts harmful NOx into nitrogen and water vapor under high-temperature conditions. Using a properly specified DEF prevents deposits and preserves catalyst performance for reliable emissions control.

• Formulated for SCR-equipped diesel engines to support NOx reduction.
• Ultrapure composition minimizes crystallization and injector fouling.
• Meets ISO 22241 purity standards required by OEM systems.

Will this DEF work with my vehicle and fueling routine?

Prime Guard DEF is compatible with diesel vehicles that require AUS 32/DEF meeting ISO 22241. It is packaged for straightforward storage and use—open and pour into the vehicle’s designated DEF tank while following manufacturer refill intervals and vehicle alerts.

• API certified and compliant with AUS 32 and DIN 70070 concentration expectations.
• Sold in a one-gallon container for convenient top-ups and portability.
• Ready-to-use; no mixing or dilution needed before refilling your DEF tank.

What handling and storage precautions should I follow?

DEF is a non-flammable, urea-based aqueous solution but should be stored cool and out of direct sunlight to preserve quality. Keep containers sealed when not in use and avoid contamination from fuels, oils, or other liquids that can damage SCR components.

• Store between recommended temperatures and keep the cap tightly closed.
• Handle with clean, dry equipment to prevent impurities entering the DEF tank.
• Dispose of empty containers in accordance with local regulations.

Who is this for: Prime Guard PRIM00203 1-gallon DEF is suited to owner-operators, fleet managers, and technicians who maintain light- to heavy-duty diesel vehicles equipped with SCR systems and need a certified, ready-to-use DEF to keep emissions systems functioning correctly. It’s also a practical choice for drivers who prefer to carry a portable supply for refill convenience between service stops.