How should I handle diesel exhaust fluid in the shop?
Short answer: Store DEF in clean, dedicated containers out of direct sunlight, use dedicated funnels and pumps to avoid contamination, and wear gloves and eye protection when handling it.
DEF is a solution of urea in purified water, and it is sensitive to contamination. Small amounts of dirt, oil, coolant or fuel can damage the SCR catalyst and the DEF pump and injector, leading to expensive repairs. Use dedicated containers, funnels and pumps made of DEF-compatible materials, and never reuse containers that held other fluids.
DEF degrades faster when stored hot and in direct sunlight, so keep bulk containers in a shaded, moderate location and rotate stock. It freezes in cold weather, which is normal and does not harm it once thawed.
Spilled DEF dries into white crystals that corrode metal and electrical connectors, so rinse spills with plenty of water rather than wiping them. DEF can irritate skin and eyes, so wear gloves and safety glasses when filling and when working on DEF system components. If DEF is accidentally put in the fuel tank, do not start the engine.
Tools used for this job
General guidance only. Follow the vehicle and tool manufacturer's procedures, and confirm vehicle coverage on the tool maker's list before buying.