How long will food last in a fridge or freezer without power?

How long will food last in a fridge without power?

Food lasts about 4 hours in a fridge without power if you keep the door shut. The US, UK and Scottish food agencies all give this figure. After 4 hours, perishable food such as meat, fish, eggs and cooked leftovers should be thrown out unless a thermometer shows the fridge never passed the limit.

The limit differs by country. The US guidance uses 40°F (4°C). The UK Food Standards Agency allows a fridge to go up to 8°C (46°F) in a power cut. If it reaches 8°C or above, chilled food should be eaten within 4 hours and otherwise discarded.

Australia is stricter on the clock. The Food Safety Information Council says food can remain safe in a fridge for 2 hours. It says food kept above 5°C for 4 hours or more should be thrown out.

How long can a freezer go without power?

A full freezer keeps food frozen for about 48 hours, and a half-full freezer for about 24 hours, if the door stays closed. These figures come from the UK Food Standards Agency, Food Standards Scotland and the US guidance. The UK agencies say they are estimates that vary with the make, model and room temperature.

Australia gives a range. The Food Safety Information Council says an efficient freezer with good door seals can keep food frozen for between 1 and 2.5 days (24 to 60 hours).

A full freezer lasts longer because frozen food acts as a cold store for the rest. A half-full freezer has more air to warm up. Packing food together and keeping the door shut both help.

Timeline: what the guidelines say hour by hour

No food agency publishes a temperature curve. What they publish are cut-off points. The table below puts those points on one timeline, for a household whose fridge and freezer doors stay closed.

Time without power	Fridge	Full freezer	Half-full freezer
0 to 2 hours	Safe (Australia: safe for 2 hours)	Frozen	Frozen
2 to 4 hours	Use or move food (Australia: use it immediately or move it to a cooler with ice)	Frozen	Frozen
4 hours	US and UK cut-off for perishables; Australia: throw out food above 5°C for 4 hours or more	Frozen	Frozen
24 hours	Past every cut-off above	Within the estimate	Estimated limit reached
48 hours	Past every cut-off above	Estimated limit reached	Past the estimate

Read the freezer columns as the point where agencies stop giving any estimate. A freezer can be partly thawed before the limit, so check ice crystals and temperature rather than the clock alone.

Can I keep or should I throw it out? Food by food

Whether to keep a food depends on the food and on how warm it got. The table compares the US FoodSafety.gov chart, the UK Food Standards Agency and the Australian council. Where a source does not list a food, the cell says so.

Food	US (FoodSafety.gov, FSIS)	UK (FSA)	Australia (FSIC)
Raw or cooked meat, poultry, fish	Discard if held at 40°F (4°C) or above for more than 2 hours	Discard after 4 hours if the fridge reached 8°C (46°F) or above	Discard if above 5°C for 4 hours or more
Eggs and egg dishes	Discard if above 40°F for more than 2 hours	Not listed separately; chilled food follows the 4-hour rule	Not listed separately; cold food follows the 4-hour rule
Soft cheese	Discard	Not listed separately; chilled food follows the 4-hour rule	Not listed separately; cold food follows the 4-hour rule
Hard cheese, butter, margarine	Keep	Not listed separately	Not listed separately
Leftovers and cooked meals	Discard after 4 hours	Discard after 4 hours at 8°C or above	Discard if above 5°C for 4 hours or more
Canned and ambient food	Not covered in the chart	Safe to eat as normal	Not covered in the leaflet

The 2 hour and 4 hour figures mean different things. The 4 hours is how long a closed fridge stays cold. The 2 hours is how long a perishable food can sit at 40°F (4°C) or above before it should go. The guidance says that if you are unsure, throw it out.

Do not taste food to test it. The FSIS guidance says never to taste food to judge its safety.

How long will meat last in a freezer without power?

Frozen meat lasts as long as the freezer stays frozen, about 24 to 48 hours with the door closed. Once the freezer warms, the test is the meat itself. FoodSafety.gov says raw meat, poultry and seafood that still has ice crystals can be refrozen, but must be discarded if it reached 40°F (4°C) or above for more than 2 hours.

Ice cream is discarded in both cases, according to the same chart. Hard cheeses can be refrozen. Soft cheese, shredded cheese and milk can be refrozen only if they still have ice crystals or are at 40°F or below.

The UK Food Standards Agency suggests eating food in this order: chilled food first, then defrosted food that needs no cooking, then perishables kept at room temperature, then canned and dried food.

How to check with a thermometer: a worked example after 9 hours

An appliance thermometer turns a guess into a reading. The USDA recommends one in the fridge and one in the freezer, with targets of 40°F (4°C) or below and 0°F (-18°C) or below. The example below is illustrative, not a test. The numbers are made up to show the method.

Power goes out at 6 p.m. and returns at 3 a.m. That is 9 hours. The doors stayed shut except once.

1. Fridge, clock check. 9 hours is more than double the 4-hour limit. The clock alone says discard perishables.
2. Fridge, thermometer check. The thermometer reads 52°F (11°C). That is above the US 40°F limit and above the UK 8°C (46°F) limit. Throw out meat, fish, eggs, leftovers and soft cheese. Butter and hard cheese are listed as keep by FoodSafety.gov.
3. Full freezer, clock check. 9 hours is 19% of the 48-hour estimate (9 ÷ 48 = 0.1875). Expect food to be frozen.
4. Half-full freezer, clock check. 9 hours is 38% of the 24-hour estimate (9 ÷ 24 = 0.375). Still inside the estimate, but with less margin.
5. Freezer, thermometer check. The thermometer reads 10°F (-12°C), and the chicken in the bag still has ice crystals. It is safe to keep and refreeze under the FoodSafety.gov rule.

If the freezer had read 42°F (6°C), the answer for meat depends on how long it sat at or above 40°F. With no way to know, discard it. The checklist: door closed, thermometer reading, then ice crystals.

What to do during the outage to buy time

Keeping the doors closed is the main step. Opening the fridge or freezer lets cold air out and shortens the time. The Food Safety Information Council says to avoid opening either door.

Other steps the agencies give:

• Move food to a cooler. The FSIS says to pack refrigerated food in a cooler with ice or frozen gel packs and keep it at 40°F (4°C) or below. The Australian council says to move food into the freezer or an esky (cooler) with ice bricks after 2 hours.
• Use the cold outside. The UK agency says food can be stored outdoors if it is below 8°C, in a sealed box, out of direct sunlight and protected from animals.
• Eat perishables first. Eat the food that spoils fastest before opening canned goods.
• Check on vulnerable people. The UK agency advises extra care for people who are vulnerable to food poisoning.

For the wider checklist of what to stock before an outage, see the power outage emergency kit guide. More guides are listed on the guides page.

When food makes someone ill, with vomiting, diarrhoea or fever, contact a doctor or your national health line. Call emergency services for severe symptoms.

Limits of this guidance

These timings are estimates for typical fridges and freezers. The UK Food Standards Agency says fridge and freezer temperatures vary with the make, model and room temperature. A full, new, well-sealed freezer in a cool room may do better. An old fridge in a hot kitchen may do worse.

The agencies disagree in small ways, shown in the tables above. When two rules conflict, follow your own country’s agency and use the stricter reading if you are unsure.