Diesel exhaust fluid (DEF) is an aqueous urea solution made with 32.5 percent high-purity urea (AUS 32) and 67.5 percent deionized water. DEF is used as a consumable in Selective Catalytic Reduction (SCR) in order to lower NOx concentration in the diesel exhaust emissions from diesel engines. PRODUCT SPECIFICATION SHEET Urea Liquor 50% â?? DEF Grade Typical Chemical Analysis Parameter Specification Urea Concentration, wt.% 50.0 +- 1.0 Free Ammonia (alkalinity), wt.% 0.31 max Biuret, wt.% 0.46 max Parameter Typical Urea Concentration 32.5 +- 0.7 % Density at 20 oC 1087.0 â?? 1093.0 kg/m3 Refractive Index at 20 oC 1.3814 â?? 1.3843 Free Ammonia (alkalinity) 0.2% max Biuret 0.3% max Aldehydes 5 ppm max Insoluble Matter 20 ppm max Phosphates 0.5 ppm max Calcium 0.5 ppm max Iron 0.5 ppm max Copper 0.2 ppm max Zinc 0.2 ppm max Chromium 0.2 ppm max Nickel 0.2 ppm max Aluminum 0.5 ppm max Magnesium 0.5 ppm max Sodium 0.5 ppm max Potassium 0.5 ppm max Water Quality DEMIN â?? ISO 3696 Applicable
