SCR is an emission-control technology that injects a precise amount of DEF into a diesel-powered vehicle’s exhaust stream, which in turn converts any nitrogen oxide present into harmless nitrogen and water vapor that is subsequently released safely into the atmosphere. Some estimate that DEF demand will reach 1.3 billion gallons annually in the United States by 2019.

Prestone’s Command DEF is a colorless, odorless, non-toxic and non-flammable liquid solution consisting of 67.5% demineralized water and 32.5% high-quality automotive-grade urea. It meets all API and ISO 2224-1 manufacturing specifications. DEF will corrode certain metals, such as aluminum, copper and brass, so it must be used and stored with dispensing equipment and tanks that are made of stainless steel or high-density polypropylene. Prestone Command DEF is available in 1- and 2.5-gallon (3.78- and 9.45-liter) containers, as well as 55-gallon (208.2 liter) drums and 330-gallon (1,249.19 liter) totes.