How to Keep Food Safe When the Power Goes Out

This guide is for anyone who has stood in front of a dark fridge after a power cut wondering what is still safe to eat. You will learn how to keep cold food cold for as long as possible, how to judge what to keep and what to throw away, and how to prepare so the next outage costs you less. In any emergency, call your local emergency number and follow the advice of official emergency services and your government, which always overrides this guide. Food safety rules can differ between countries, so always check your national food safety agency. General information, not professional advice.

Why Power Cuts Put Food at Risk

Bacteria that cause food poisoning grow slowly in cold food and much faster once it warms up. A fridge and freezer only keep food safe while they hold it at a low enough temperature. When the power goes out, the clock starts running, and how long food stays safe depends on how cold it was to begin with, how full the appliance is and how often the door is opened.

The difficulty is that unsafe food often looks, smells and tastes normal. Bacteria that cause illness do not always cause spoilage. That is why food safety agencies rely on time and temperature rather than appearance, and why the safest rule is simple: when in doubt, throw it out.

Losing a fridge full of food is frustrating and expensive, but food poisoning is far worse, especially for young children, pregnant people, older adults and anyone with a weakened immune system. This guide helps you save as much as you safely can.

The First Steps When the Power Goes Out

What you do in the first few minutes makes the biggest difference to how much food you keep.

1. Keep the doors closed Every time you open the fridge or freezer, cold air escapes. Decide what you need before opening the door and close it quickly.
2. Note the time Write down when the power went off. This helps you work out later how long food has been without cooling.
3. Check official updates Look for updates from your power company or local authorities on how long the outage is expected to last, using a battery radio or a charged phone.
4. Eat from the cupboard first Use shelf-stable foods such as bread, tinned foods and dry snacks before opening the fridge.
5. Plan for a longer outage If the outage looks likely to last more than a few hours, think about cool boxes with ice or ice packs for the most important perishable items.

Commonly cited guidance from food safety agencies is that an unopened fridge will usually keep food cold for around four hours, a full freezer for around 48 hours and a half-full freezer for around 24 hours. These are general guidelines; your appliance, room temperature and how often the door has been opened all make a difference. Check your national food safety agency for the guidance that applies where you live.

Never use a generator, barbecue, camping stove or gas heater indoors, in a garage or near open windows to cook or keep warm during an outage. These produce carbon monoxide, which has no colour or smell and can kill. Keep a battery-powered carbon monoxide alarm at home and follow the manufacturer's instructions for any generator, which must only ever be used outdoors and well away from the building.