This month marks the 10th anniversary of the American Petroleum Institute’s voluntary program for certification of diesel exhaust fluid‘s quality. Essentially, the program is modeled on the API’s similar, decades-old quality-certification program for engine oils, well-known as a valuable marker for oil buyers to know that what they’re getting is up to spec.
For much of those first 10 years, the DEF quality-cert team lead at the API, Jeff Harmening, has worked to refine the program, which he calls in its conception a quality-control effort to “create this brand-new industry out of thin air and have it be successful.” That brand-new industry — the sale and use of DEF for EPA 2010-emissions-spec engines with selective catalytic reduction (SCR) exhaust aftertreatment systems.
With plenty new players getting into the business of DEF production at the time, “the marketers knew we had a [certification] program in place for engine oils that was reliable and globally accepted,” Harmening says. With concerns about DEF quality growing, “marketers asked us to put that together to ensure quality DEF in the marketplace that consumers could easily find.”
The program, however, is a completely voluntary one that is funded in part by participating marketers (they pay a fee to license their products through it), and not all DEF sellers participate. (You can access the current list of licensees whose products are part of the program via this link.) You’ll know the product is certified when you see the mark shown here on DEF sold in containers, but at bulk distribution points at truck stops, fuel stations and on fleet yards, it like as not won’t be obvious.
Issues that can arise with out-of-spec DEF include the perhaps most obvious one — improper urea concentration, which at a drastic-enough level can trigger a derating of the engine. As I’ve written before, this often happens not as a result of anything the DEF manufacturer did in formulating the product, but rather follows from longer-term storage at high or low temperatures, particularly problematic at high temps.
High temperatures over enough time can degrade the DEF and throw off the urea concentration, giving any DEF so stored a “shelf life, Harmening says. “If stored above 86 degrees Fahrenheit, recommended [maximum] storage time above 86 is about 12 months. For those guys hauling a jug just in case they’re out on the middle of nowhere” with a need to fill, “that may be off-spec DEF by the time they crack the seal.”
Cold-weather isn’t really an issue, he says, given DEF is formulated at 32.5 percent urea and the rest distilled water for the reason that, at that level of concentration, both substances freeze and thaw at the same time. Thus “you don’t have to worry about the concentration being off” in a cold area when your tanks freeze.
