DEF storage and handling in a Canadian winter
DEF freezes at -11°C, expands about 7% when it does, and returns to full specification after thawing. The problems fleets encounter in winter are practical ones: burst containers, frozen dispensing equipment, and refills that were not scheduled ahead of the cold.
Winter handling guidelines
- Leave headspace: never fill rigid containers to the brim in winter (7% expansion needs somewhere to go)
- Keep dispensing equipment (pumps, hoses, nozzles) indoors or heated. The fluid survives freezing; the equipment may not
- No additives, ever. Anything added to DEF puts it out of ISO 22241 specification and risks the SCR system
- On-vehicle tanks require no intervention: trucks are engineered to start with frozen DEF and thaw the line as the engine warms
- Store below 25°C year-round. Heat, not cold, is what degrades DEF
Yard storage options that work at -20°C
Indoor tote storage is the simplest arrangement. Outdoor stationary tanks perform well with insulation and a heating element, standard equipment we specify as part of a bulk DEF program. The other half of winter readiness is scheduling: consumption rises in winter with increased idling and cold starts, so refill schedules should tighten before January, not after the first empty tank.
Common questions
Does DEF freeze?
Yes. DEF freezes at -11°C and expands about 7% when it does. Freezing does not damage it: once thawed, DEF returns to full strength with no loss of quality.
Can I add anything to DEF to stop it freezing?
No. Additives put DEF out of spec (ISO 22241) and can damage the SCR system. Use heated storage, insulated totes, or simply let on-vehicle tanks thaw. Trucks are designed to start and run while the DEF line warms up.
How long does DEF last in storage?
Roughly 24 months when stored below 25°C out of direct sunlight; closer to 12 months if regularly stored above 30°C. Winter cold does not shorten shelf life. Heat does.
Our tankers deliver DEF throughout the winter, on schedules set before the cold arrives.