Expectations for shelf life as defined by ISO Spec 22241-3 are the minimum expectations for shelf life when stored at constant temperatures. DEF will degrade over time depending on temperature and exposure to sun light. The shelf life of DEF is a function of ambient storage temperature. While the optimum storage temperature is up to 77 deg F (25 deg C), temporary exposure to higher temperatures has little to no impact on the quality of DEF. If the ISO standards should change to allow antifreeze additives, Cummins Filtration will ensure our product continues to meet ISO requirements.Īre there special storage requirements for DEF?ĭEF should be stored in a cool, dry, well-ventilated area, out of direct sunlight. Additives of any type are not approved for use in DEF today. Any further blending or adjusting of the DEF mixture will impede its ability to perform correctly and may cause damage to the SCR components. While an additive could improve freeze point of the mixture, the 32.5% solution is very specific to providing NOx reducing properties. The freezing and unthawing of DEF will not cause degradation of the product.Ĭan an anti-gelling or freeze point improver be added to the DEF to prevent it from freezing? The SCR heating system is designed to quickly return the DEF to liquid form and the operation of the vehicle will not be impacted. If DEF freezes when the vehicle is shut down, start up and normal operation of the vehicle will not be inhibited. How do I keep the DEF from freezing? What happens if the DEF freezes in the tank on the vehicle?ĭuring vehicle operation, SCR systems are designed to provide heating for the DEF tank and supply lines. DEF packaging and tanks are designed to allow for expansion.ĭEF weighs approximately 9 pounds per gallon. Yes, DEF expands by approximately 7% when frozen. The freezing and unthawing of DEF will not cause degradation of the product. At 32.5%, both the urea and water will freeze at the same rate, ensuring that as it thaws, the fluid does not become diluted, or over concentrated. Also, SCR systems will be calibrated to the 32.5%, so that optimum NOx will be reduced during operation.Ī 32.5% solution of DEF will begin to crystallize and freeze at 12 deg F (-11 deg C). Yes, The 32.5% urea concentration is the ideal solution as it provides the lowest freeze point. Cummins Filtration DEF currently meets ISO specification and is also API certified. For more information about the quality standards, refer to ISO22241 which details specifications for DEF quality, handling, testing, transportation storage, and refilling.ĪPI Certification is a voluntary program establishedby the American Petroleum Institute (API) which certifies and monitors that diesel exhaust fluid meets ISO specifications. It is recommended that end users purchase certified DEF and avoid blending it themselves. Cummins and other OEMs require that DEF used with their SCR systems meet all ISO22241 specifications as well as API certification requirements. DEF has strict requirements for maintaining concentration and purity of ingredients that is critical to the proper functioning and longevity of the SCR system. For more information on these specifications, visit Can I make DEF myself?Ĭummins Filtration does not recommend customers make DEF themselves. This will ensure the proper purity and concentration (32.5%) of urea. The DEF you purchase should state and display the certification of the American Petroleum Institute(API), German Institute of Standardization DIN70700, the International Organization for Standardization ISO 22241-1, and meet AUS - 32 specifications. How will I know that the DEF product I purchase will work? It is used in a variety of industries, including as a fertilizer in agriculture. Urea is a compound of nitrogen that turns to ammonia when heated. It is a carefully blended aqueous urea solution of 32.5% high purity urea and 67.5% deionized water. DEF is the reactant necessary for the functionality of the SCR system.