Food Safety During a Power Cut

The clock is not the only thing that matters

Temperature is what determines food safety, but most homes do not monitor fridge temperature continuously. The Food Standards Agency therefore gives practical time estimates for a closed appliance during a power cut.

A power cut lasting less than four hours is unlikely to affect the safety of chilled or frozen food. For longer outages, a closed fridge should stay cold for up to four hours. A full freezer may hold temperature for up to 48 hours, while a half-full freezer may manage around 24 hours. Appliance type, room temperature and how often the door is opened all change those numbers.

For households in Scotland, Food Standards Scotland publishes separate official power-cut food safety guidance. Its fridge and freezer estimates are consistent with the FSA figures above; both emphasise thermometer readings and limiting door opening. Check the advice for your nation when available.

Keep the doors shut

Every time a fridge or freezer door opens, cold air is replaced by warmer room air. Decide what you need before opening it. If you have a fridge thermometer, use it rather than guessing.

The FSA normally recommends keeping a fridge at 5°C or below. In a power cut, its guidance allows food to be stored in a fridge below 8°C. If the fridge temperature reaches 8°C or above, the FSA says to eat foods that normally need refrigeration within four hours. Discard those foods after four hours unless the power was restored within that period. This applies to items with a use-by date, foods labelled keep refrigerated and refrigerated leftovers. If you cannot establish how long food was too warm, do not assume it is safe; check the official advice.

Eat in the right order

Use food that is most temperature-sensitive before opening tins and cupboard food. Shelf-stable food remains your fallback when refrigeration is no longer reliable. That is one reason a modest no-cook food shelf belongs in an emergency plan even if you own a camping stove.

If it is genuinely below 8°C outside, the FSA notes that food can be stored outside in clean, dry conditions, protected from sunlight, animals and contamination. Use a sealed box rather than putting food loose outdoors.

Do not rely on smell alone

Food can be unsafe without smelling obviously spoiled. When the cold chain has been lost, use the Food Standards Agency guidance rather than a sniff test. If you are uncertain about a high-risk food, caution is cheaper than food poisoning.

Plan for an outage without wasting food

Keep a thermometer in the fridge, know roughly how full the freezer is and keep a simple supply of food that works without refrigeration. A manual tin opener and insulated flask are small items that remain useful in normal life too. If you need to prepare infant formula during an outage, the FSA advises using boiled water for powdered formula preparation; if you cannot boil water, ready-to-feed infant formula may be an alternative. Follow current NHS infant-feeding instructions and do not improvise with untreated water.

Useful kit for this plan

Equipment should support the plan, not replace it. The commercial catalogue is kept on a separate page.

Sources checked for this guide

We use public sources for the factual backbone and write the guide in our own words. Source pages can change, so the links below are the place to check current official advice.

Editorial review date: 13 October 2026. If an official source conflicts with this page, follow the official source.