HP DEF (Diesel Exhaust Fluid) is a premium-grade Aqueous Urea Solution (AUS 32) formulated in accordance with ISO 22241 and IS 17042 (Part 1) specifications. It is a high-purity, non-toxic, and colorless fluid specifically engineered for use in diesel engines equipped with Selective Catalytic Reduction (SCR) technology. HP DEF plays a critical role in reducing harmful nitrogen oxide (NOx) emissions — one of the major pollutants produced during diesel combustion — by chemically converting them into harmless nitrogen and water vapor.

Test Characteristics UOM Specifications Test Method
Aldehyde PPM 0-5 ISO 22241-2 Annex F
Alkalinity as NH3 % 0-0.2 ISO 22241-2 Annex D
Biuret % 0-0.3 ISO 22241-2 Annex E
Density @ 20°C Kg/m³ 1087.0-1093.0 ISO 12185
Insoluble PPM 0-20 ISO 22241-2 Annex G
RI @ 20°C 1.3814-1.3843 ISO 22241-2 Annex C
Urea content % 31.8-33.2 ISO 22241-2 Annex B or C
HP DEF barrel