This program is accredited in accordance with the recognized International Standard ISO/IEC 17043: 2010 Conformity Assessment - General Requirements for Proficiency Testing, by the American Association for Laboratory Accreditation. Certificate Number: 4209.01
ASTM’s Diesel Exhaust Fluid (DEF) Proficiency Testing Program provides laboratories with a statistical quality assurance (SQA) tool, enabling labs to compare, improve, and maintain a high level of performance in the use of ISO methods with other laboratories worldwide. Diesel Exhaust Fluid (DEF), as standardized in ISO 22241, is an Aqueous Urea Solution of with 32.5% high-purity urea (AUS 32) and 67.5% deionized water.
DEF is a consumable required by many modern diesel engine applications using selective catalytic reduction (SCR) technology to reduce oxides of nitrogen (NOx) exhaust. Impurities in the DEF can cause the SCR, which is part of the engine’s powertrain configuration, to fail. As a result, it is both beneficial and important to maintain DEF quality standards and testing.
For more information, contact us.
You receive test results available only to participating laboratories that will help you:
Should you have an issue with your published results, please write to firstname.lastname@example.org with your lab number and account number.
Two liters of diesel exhaust fluid will be used in the program for each test cycle.
Test Parameters (subject to change):
ISO 22241-5 — 2012 Diesel engines
Nox reduction agent AUS32
Density at 20C
Annex B/C Urea Content Refractive Index
Urea Content (Total Nitrogen)
Annex C Refractive Index at 20C
Annex D Alkalinity as NH3
Annex E Biuret content
Annex F Aldehydes content
Annex G Insoluble Matter content
Annex H Phosphate (PO4)
Annex I Ca, Fe, Cu, Zn, Cr, Ni, Al, Mg, Na, K
Annex J Identity (FTIR)
NOTE: List of Methods Subject to Change. Participation is not contingent upon performing all program tests.
Test samples are prepared and distributed for ASTM International by SGS North America Deer Park, TX. Program registration fees include the cost of shipping test samples to U.S. participants or, for international participants, to a third party shipping agent located in the U.S.
IMPORTANT for Intercontinental participants: You have the following options for receipt of samples:
Upon completion of tests, each laboratory electronically submits their test data to ASTM for use in generating statistical summary reports. Reports contain:
Committee D15 on Engine Coolants, consists of over 220 members and developers of over 55 ASTM standards, provides the technical direction for the program. Test information generated through the program is utilized by Committee D15 to determine if modifications to ASTM documents or new methods are warranted. Data submitted to Committee D15 is coded to maintain lab confidentiality.