Shelf Life of Diesel Exhaust Fluid DEF

July 10, 2019by tyrussum


Diesel Exhaust Fluid DEF Shelf LifeThis article is to help you understand the shelf life and sensitivity of DEF. Diesel Exhaust Fluid (DEF) is a blend of urea and de-ionized water produced to an international standard (ISO 22241). In other words, it is used to reduce the nitrogen oxide concentration in diesel exhaust emissions from diesel engines. However, it is not hazardous, but DEF is corrosive for some metals and needs to be properly stored in containers made of appropriate materials.

How Should DEF Be Stored?

The typical shelf life of Diesel Exhaust Fluid (DEF) is usually 2 years. However, to help maximize your shelf life it’s recommended to store it between 68°F and 23°F (20°C and -5°C). There are several factors that can play a role in reducing the overall shelf life, so be sure to follow the recommendations below:

  • If you store DEF outside, it must be kept out of direct sunlight and stay under shade. If it is kept in direct sunlight for any sustained period of time, it begins to lose its urea potency.
  • DEF must be stored below 86°F or in the coolest area of your storage facility.
  • If you are storing DEF in a climate reaching an average of 95°F or higher, you must manage your inventory accordingly and keep it to a minimum.
  • DEF will freeze and begin to look like a crystalline slush once it hits 12°F (-11°C). Do not store your DEF in outside climates where the temperatures fall below 23°F (-5°C), unless your storage container is “winter-friendly.”
  • If DEF is stored at higher temperatures for any prolonged period of time, it can evaporate. DEF is 67.5% water, so to avoid the risk of evaporation, be sure to keep your DEF tank and storage containers securely closed.


For instance, below will show a representation of the shelf life of Diesel Exhaust Fluid continuously exposed to temperatures ranging from 68°F to 23°F for the entire time period. Shelf life for DEF inventory should always be based on the average daily temperature, not necessarily the day’s max temperature reached.

Diesel Exhaust Fluid Storage Temperature and Shelf Life

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What DEF Equipment Options Are Available From Envirosafe?

Diesel Exhaust Fluid (DEF) is very corrosive for metals such as carbon steel, aluminum, copper, and zinc. DEF should never be stored in containers made of these materials. In conclusion, any equipment or component you have that will come into contact with the DEF should be made of stainless steel or high-grade polyethylene. Envirosafe offers a  variety of solutions that are specifically for DEF. Below are a those items.

Feel free to contact us today with questions about Diesel Exhaust Fluid (DEF), our DEF specific equipment or to discuss existing or new above ground fuel storage tank projects.


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