Proper Storage Protection for Your Diesel Exhaust Fluid

In 2010, the Environmental Protection Agency mandated the use of selective catalytic reduction (SCR) in diesel engines. In an SCR-equipped vehicle, the exhaust gas from the engine goes through a particulate filter to eliminate the soot and ash generated from burning diesel fuel.


The SCR system sprays diesel exhaust fluid (DEF) into the exhaust gas to help eliminate the NOx emissions in diesel engines. DEF is a combination of urea and deionized water. The urea from the DEF and the exhaust gas react with a variety of metallic compounds to convert nitrogen dioxide and monoxide into nitrogen and water. 

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It is critical that the diesel engine fluid stays pure. Impurities can cause the SCR system to stop, which will shut down the operation of the truck.

Poly Processing works with DEF manufacturers and distributors to provide reliable storage solutions that ensure their DEF stays pure.

Diesel Exhaust Fluid Storage Considerations

DEF solution is a clear, non-toxic chemical. It is safe to handle, but it can corrode certain metals, so it is important to design a bulk storage system that can give you top performance for many years.

DEF Storage Solutions

Safely protecting the purity of the diesel exhaust fluid is the number one goal of a storage system. Since DEF is a high-purity chemical, it should receive the same level of storage treatment as other high purity chemicals. 

Never store DEF in a used chemical tank and never add any chemicals or water to the chemical solution.

Download our Diesel Exhaust Fluid Guide

DEF should be stored at an optimal temperature to reduce the chance of separation and settling. In some cases, heat pads and insulation may be required for the tank contents to maintain the proper temperature.

To maintain the purity of DEF, proper and complete discharge is required to remove any sediments and impurities. Without complete discharge, impurities can eventually build up and contaminate the entire supply of DEF solution.

Poly Processing’s Integrally Molded Flanged Outlet (IMFO®) system is ideal for storing DEF, because it provides a full drain, without requiring additional maintenance. The IMFO® fitting is a homogenous flange system that is molded as part of the tank while it is being manufactured, making it a stress-free part of the tank. The flange is created from the same material as the tank — it’s not an insert added during or post-production.


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The one-piece construction enables the flange to be placed at the very bottom of the tank’s sidewall, below the knuckle radius—not two inches above it. IMFO tanks are full-discharge polyethylene tank systems which provide a true full discharge of your stored chemicals.

The Vertical IMFO tank system is available up to 15,500 gallons, and the Sloped-bottom IMFO tank system is available up to 15,000 gallons.

For more information on safely storing diesel exhaust fluid, download our diesel exhaust fluid guide.

Questions about storing corrosive chemicals?