Power Cut Food Safety Timer
When the power goes off, start the timer to see how long the food in your fridge and freezer stays safe, and what to throw away if the power stays off.
Last updated
Fridge
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Keeps food cold for about 4 hours if the door stays shut.
Freezer
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If the fridge has been off for more than 4 hours
These apply to food that has been above 4 °C (40 °F) for more than 2 hours. A fridge thermometer reading 4 °C or below means the food is still fine. Never taste food to decide if it’s safe, and throw out anything that smells, looks or feels wrong. When in doubt, throw it out.
Throw away
- Raw or cooked meat, poultry, fish and seafood, including deli meats and hot dogs
- Milk, cream, yoghurt, soft cheeses and grated cheese
- Eggs and egg dishes, custards and puddings
- Leftovers, cooked pasta, rice and potatoes, casseroles, soups and stews
- Pizza, and cakes or pastries with cream or custard fillings
- Opened tins of meat or fish
Usually safe to keep
- Hard cheeses (such as Cheddar and Parmesan), processed cheese
- Butter and margarine
- Whole, uncut raw fruit and vegetables
- Fruit juice, dried fruit
- Opened jam, peanut butter, ketchup, mustard, pickles and olives
- Bread, rolls, plain cakes and muffins
Freezer: food that still has ice crystals, or is at 4 °C (40 °F) or colder, can be refrozen or cooked. Its quality may suffer, but it’s safe.
How to keep food safe in a power cut
- Tap The power just went off, or enter when it went off. The timer is kept in this browser, so you can close the page and come back.
- Keep the fridge and freezer doors shut: a closed fridge stays cold for about 4 hours, a full freezer for about 48.
- When the power comes back, tap The power’s back to see where things stood, then check the food against the lists.
Where the times come from
The times are from FoodSafety.gov and the US Department of Agriculture (USDA): an unopened fridge keeps food cold for about 4 hours; a full freezer holds its temperature for about 48 hours, or 24 if it’s half full, as long as the door stays shut. Opening the doors lets the cold out, so the calculator warns you the times will be shorter. Food that has been above 4 °C (40 °F) for more than 2 hours, which includes most of the fridge after 4 hours off, should be thrown away if it’s perishable; the lists follow FoodSafety.gov’s chart.
An appliance thermometer settles it: a fridge at 4 °C (40 °F) or below is fine whatever the clock says. To make the cold last longer, keep the doors shut, put bags of ice or frozen water bottles in the fridge, and group frozen food together.
The start time is kept only in this browser (see Your data), so the timer is still running if you close the page.
Sources
Checked on 18 October 2026.
- FoodSafety.gov: Food safety during a power outage the 4-hour fridge and 48/24-hour freezer times, and which refrigerated and frozen foods to keep or throw away.
- USDA FSIS: Keep your food safe during emergencies thermometers, refreezing, and keeping food cold for longer.
Questions about food in a power cut
How long does food last in the fridge without power?
About 4 hours if you keep the door shut. After that, throw away perishable food such as meat, fish, milk, eggs and leftovers, unless a thermometer shows the fridge is still at 4 °C (40 °F) or below.
How long does a freezer stay frozen in a power cut?
About 48 hours if it’s full and the door stays shut, or about 24 hours if it’s half full.
Can I refreeze food that has started to thaw?
Yes, if it still has ice crystals or is at 4 °C (40 °F) or colder. It may lose some quality, but it’s safe.
Is cheese safe after a power cut?
Hard cheeses such as Cheddar and Parmesan are usually safe. Soft cheeses, such as brie, mozzarella and cottage cheese, and grated cheese should be thrown away if they’ve been above 4 °C for more than 2 hours.