Sub-Frost Heat Transfer Fluid
DEF

DEF — Diesel Exhaust Fluid

ISO 22241 diesel exhaust fluid for SCR-equipped diesel engines and fleets.

DEF — Diesel Exhaust Fluid container

Specifications

Technical specifications for DEF
Operating range Store 12°F to 86°F; freezes at ~12°F (−11°C) and thaws without degradation
Inhibitor system 32.5% high-purity automotive-grade urea in deionized water, meeting ISO 22241-1 (AUS 32)
ASTM standards ISO 22241
Pre-mix concentrations 32.5% urea (ready to use)
Package sizes 2.5-gal jugs (2/case), 55-gal drums, 275-gal totes, Bulk tanker

Documentation

Free to download, no form required.

Technical & safety documentation available on request. Ask our team.

Overview

DEF (Diesel Exhaust Fluid) is a high-purity solution of 32.5% automotive-grade urea in deionized water that meets ISO 22241, the international standard for AUS 32 / AdBlue-equivalent fluid. It is metered into the Selective Catalytic Reduction (SCR) system of modern diesel engines, where it converts harmful NOx emissions into harmless nitrogen and water vapor.

DEF is not a heat transfer fluid. Sub-Frost stocks it for the fleet, agricultural, construction, and equipment operators who already rely on us for bulk fluids. It is available from 2.5-gallon jugs up to bulk tanker, with the same blend-to-spec quality control and fast regional delivery.

Applications

  • SCR-equipped on-road trucks & fleets
  • Agricultural & construction diesel equipment
  • Diesel generators & power units