The Heavy Equipment Operator's Guide to Handling DEF Off-Road

DEF Purity is Essential to SCR Systems

DEF is easily contaminated and off-road environments are, quite frankly, dirty. This two-page guide will help you understand the best practices for delivering DEF to Tier 4 machinery in the field.

Improper handling of diesel exhaust fluid at the end user level is the leading cause of SCR system failures.* Understanding DEF handling best practices will ultimately help you increase uptime and avoid costly repairs.


  • How off-road differs from on-highway.
  • What contaminates DEF.
  • How contaminated DEF affects machinery.
  • How to prevent contamination.
  • Best practices for handling DEF off-road.
  • How temperature affects DEF use and shelf life.

*Source: AMB International