How long is food safe in the fridge or freezer after the power goes out?
When electricity is interrupted, the temperature in the fridge or freezer — not the length of the outage itself — determines when food becomes unsafe. The key thresholds are 4 °C (40 °F) for refrigerated food and –18 °C (0 °F) for frozen food. In general, food in the fridge will last for about 4 hours if the door is kept closed, while your freezer has between 24 and 48hrs depending on how full it is.
Refrigerators
Maximum safe time: ≈ 4 hours with the door kept closed.
A well-sealed refrigerator will hold at or below 4 °C (40 °F) for roughly four hours. After that point, discard perishable items like meat, poultry, fish, eggs, dairy, prepared dishes, and cut produce.
Freezers
| Freezer load | Safe time with door closed |
|---|---|
| Full (≥ 75 % packed) | ≈ 48 hours |
| Half-full | ≈ 24 hours |
Solidly frozen items in your freezer extend the safe window - the more items in your freezer, the longer it can keep frozen. Filling empty space with ice packs or containers of water frozen in advance lengthens protection if you don't have much inside.
When to discard
- Refrigerated items held above 4 °C (40 °F) for more than 2 hours must be thrown out, even if they look or smell normal.
- Frozen items that still contain ice crystals or register ≤ 4 °C may be refrozen or cooked. Fully thawed foods that rise above 4 °C for over 2 hours should be discarded.
- Never rely on taste or odour as a safety check; harmful bacteria do not always change the look or smell of food.
Steps to extend the safe window
- Keep refrigerator and freezer doors closed throughout the outage.
- When you put items in your fridge and freezer, try to keep them tightly packed together to retain cold air.
- Consider getting a fridge or freezer thermometer to verify temperatures when power is restored.
Monitoring with CabinPulse
CabinPulse sends an immediate alert when mains power fails and continues to report ambient temperature via its independent cellular link.
- Confirm exactly when the power went out.
- Decide remotely whether to enlist a neighbour to add ice or move food.
It can help you avoid unnecessary food waste and prevents food-borne illness, even when the cabin is several hours away and the WiFi is down!
Key points to remember
- Refrigerator: 4 °C threshold, ≤ 4 hours unopened.
- Freezer: –18 °C baseline; 24 hours half-full, 48 hours full.
- Discard rule: Food > 4 °C for > 2 hours.
Pair appliance thermometers with continuous CabinPulse monitoring for clear decisions on whether to keep - or toss - food after an outage.
