Keep the fridge and freezer doors closed when the power goes out. A closed fridge generally keeps food cold for about four hours, according to US government food-safety guidance. If the outage reaches four hours and you cannot verify that perishable food stayed at 4°C or below, discard food such as meat, seafood, eggs, milk and cooked leftovers.
A closed full freezer usually keeps its temperature longer. The estimate is about 48 hours for a full freezer and 24 hours for a half-full one. Those are planning estimates. Use the temperature and condition of the individual food when deciding whether you can keep it.
- Keep the doors closed and note when power went out.
- Use a thermometer if you have one and assess each food separately.
- Discard risky perishables if you cannot establish safe storage.
- Never taste food to decide whether it is safe.
In this guide
Section 1 of 5
Keep the cold inside first
Write down when the outage began if you know it. Open the door only if you need to move food into another reliably cold appliance or a cooler with enough ice to maintain temperature. SFA’s ordinary household targets are 4°C or below for the fridge and −18°C or below for the freezer. The US government guidance supplies practical outage estimates. SFA’s household storage guidance · FoodSafety.gov’s emergency guidance
| What happened | What to check |
|---|---|
| Fridge power off for less than four hours with the door shut | Check temperature and apply stricter guidance if food warmed |
| Fridge power off for four hours or more | Discard risky perishables unless you can establish they stayed safely cold |
| Closed full freezer | About 48 hours is an estimate, so check individual foods |
| Closed half-full freezer | About 24 hours is an estimate, so check individual foods |
| Unknown outage duration | Use any reliable temperature history and discard risky food when unsure |
Section 2 of 5
Decide what to keep from the fridge
Meat, poultry, seafood, milk, eggs and cooked leftovers are examples of perishables to assess promptly. The US government’s item-by-item chart advises discarding many refrigerated perishables after more than two hours at 4°C or above. Use the product’s own storage guidance if it is stricter. If you do not know the food’s temperature history, the four-hour outage rule gives you a practical decision for risky foods. FoodSafety.gov’s outage chart
Some items, such as certain whole uncut fruit or unopened shelf-stable products, are assessed differently. Check the chart and the label rather than throwing away everything in the fridge as one group. A cold reading after the appliance has recovered cannot reconstruct what happened earlier.
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Section 3 of 5
Check frozen foods one by one
US guidance says many frozen foods can be refrozen or cooked if they still contain ice crystals or are at 4°C or below. Check the item-specific chart for exceptions, including ice cream, and follow any stricter product directions. Foods that were fully thawed and warm for an unknown time need a separate safety decision.
The centre of a pack can stay cold longer than its surface. If you have a food thermometer, use it as directed. Do not assume a small freezer compartment will retain cold for as long as a closed stand-alone freezer. USDA guidance on power failures
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Section 4 of 5
Reset the kitchen when power returns
Check that the fridge and freezer return to their normal operating temperatures. Clean any leaks from raw meat or thawed food and keep contaminated packaging away from other items. Restock perishables once you know the appliance is holding its temperature.
For the next outage, keep an appliance thermometer in each compartment and make a note of where you could move food if the outage is prolonged. A time note and a thermometer are more useful than guessing from how cold a carton feels.
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Section 5 of 5
Food safety questions after a power cut
Can I smell the food to see if it is safe?
Use the time and temperature history instead. Never taste food to test it.
Can I cook leftovers to make them safe again?
Reheating cannot undo unsafe storage. Discard risky food that did not stay safely cold.
What if my fridge is cold when I get home?
Check how long the power was off and what you know about the food temperature during the outage. A current reading tells you the present temperature only.