Emission Reduction Fluid and Emission Reduction Fluid Handling: Storage

WARNING: This page is about a different variant/trim than selected.

SCR systems are sensitive to potential chemical impurities in the urea solution, therefore the solvent is demineralized water. Diesel Exhaust Fluid (DEF) is an aqueous urea solution blended with 32.5% high purity urea and 67.5% deionized water.
The solution is clear, non-toxic and safe to handle. However, it can corrode some metals and must be stored and transported carefully.
DEF is stored in a tank on board the vehicle and injected into the exhaust stream by a metering system at a rate of 2% of diesel consumption volume (4-6% in Europe).
This low dosing rate ensures long fluid refill intervals and minimizes the tank's obtrusion into vehicle packaging space.
An electronic control unit adjusts the addition of fluid in accord with such parameters as engine operating temperature and speed.
Diesel exhaust fluid is offered to consumers through a variety of quantities by manufacturers ranging from containers of it for single or repeated small usage to bulk carriers for consumers that require a large amount DEF. It is recommended that it be stored in a cool, dry and well-ventilated area that is out of direct sunlight.