DEF Best Practices

Diesel Exhaust Fluid

DEF – short for Diesel Exhaust Fluid – is a liquid urea solution which reduces the amount of air pollution created by a diesel engine through Selective Catalytic Reduction (SCR.) If DEF is altered, it can lead to ineffective NOx reduction and possible non-compliance with emission standards.

Saving in Bulk – But at What Cost?

Buying in bulk is often the economical choice – but that isn’t always the case with DEF. Without proper storage and handling, you actually risk incurring higher costs due to product alteration, contamination, and degradation.

In this post, we’ll explore how DEF best practices and packaging types impact which DEF purchasing option may be best for you.

Issues and Best Practices for DEF Storage and Handling

SHELF-LIFE

DEF’s shelf-life of 2 years is dependent upon ideal conditions: Indoors, no sunlight, constant temperature of approximately 77F. DEF stored outdoors in high, fluctuating temperatures may have a shelf-life of 6 months or less: Minimize exposure to sun by storing in UV-resistant containers (such as HDPE) or storing inside.

CONCENTRATION

A change in the concentration of DEF (32.5% urea, 67.5% deionized water) can result in a drop in NOx neutralization effectiveness. Keep container properly sealed or vented to prevent ingression of water, and store in a manner than minimizes temperature swings that could lead to evaporation or condensation.

CONTAMINATION

Dust, dirt, metal particles, oils, fuels, chemicals, & additional water are all contaminants which could reduce DEF effectiveness and potentially cause SCR system malfunctions. Clean fittings and openings prior to transfers; keep containers properly sealed or vented to prevent ingression of dust and dirt; use clean, dedicated transfer equipment to prevent cross-contamination with other oils or chemicals.

DEF CHECKS

Your DEF should be clear, with the color unchanged. You can check for any changes in the concentration using a refractometer.

Which Package Type is Best for Your Work Environment?

Not all work environments are the same: While a truck stop is likely to have a high volume turnover, the ability to store under cover, and minimized exposure to the elements, a construction site is likely to have a low volume turnover, outside storage, and direct exposure to the elements and contamination.

BULK TANKS create the largest risk, as they are more likely to be stored outside (exposed to the sun and fluctuating temperatures) with high risk of ingression and longer product turnover.

TOTES AND DRUMS are easier to store inside and have a shorter turnover, but still have a high risk of ingression.

JUGS would have the least risk and best scenario for protecting the integrity of the DEF: Easy to store inside, low risk of ingression, and short turnover.