Food safety after a power outage: what to keep and what to toss

Updated 2026-10-31 · Sources linked inline

A closed refrigerator keeps food safe for up to 4 hours without power. A full freezer holds its temperature for about 48 hours (24 hours if it's half full). Throw away perishable food that has been above 40°F for more than 2 hours, and never taste food to decide. Those rules come from the USDA's guidance as published on FoodSafety.gov, and the CDC and Ready.gov repeat them. How this guide was made: this is a summary of USDA, CDC and Ready.gov guidance, with sources linked throughout. We haven't bench-tested any of the food or appliances mentioned, and we don't claim to. The rest of this page is the practical version: what to do while the power is out, then a sorted list for afterward.

The four numbers to remember

After 4 hours without power, FoodSafety.gov says to discard refrigerated perishables such as meat, poultry, fish, eggs and leftovers. These are limits for planning, not guarantees. A warm kitchen, a half-empty fridge or door openings make them shorter.

Before the outage: five cheap preparations

None of this changes the rules above, but it makes them easier to follow:

• Put an appliance thermometer in the fridge and the freezer. It costs little and answers the question later.
• Keep a cooler and a way to make ice. Ready.gov mentions coolers with ice; having them on hand saves a trip.
• Freeze water in containers in spare freezer space, so you have ice to move into a cooler. Full freezers also hold temperature longer, per the 48-hour versus 24-hour figures.
• Write down what is in the freezer. You open it less when you know what's inside.
• Plan the power. Decide now whether a generator or battery will run the fridge, so you aren't deciding at hour three.

During the outage

1. Keep doors closed. Every opening lets cold air out. Decide what you need before you open.
2. Plan what you open. Decide what you need before you open a door, and open it once. The sources above simply say to keep doors closed as much as possible.
3. Use a thermometer. Ready.gov says to monitor temperatures with a thermometer and throw food out if the temperature is 40°F or higher. A thermometer that stays in the fridge and freezer tells you what happened while you weren't looking.
4. Use coolers with ice if the outage looks long, Ready.gov says. Move the most perishable items to the cooler first, and keep checking the temperature.
5. Think about power before the 4-hour mark. If you can run the fridge on a generator or battery, the clock stops mattering as much. See what size generator to run a refrigerator and the refrigerator wattage guide for sizing, and the power station runtime calculator for batteries.

Refrigerated food: keep or discard

Below is the FoodSafety.gov chart for refrigerated food exposed to 40°F or above for more than 2 hours. "When in doubt, throw it out."

Discard

• Raw or cooked meat, poultry, fish and seafood, and soy meat substitutes; thawing meat
• Lunch meat, hot dogs, bacon, sausage, dried beef
• Meat, tuna, shrimp, chicken or egg salad
• Gravy, stuffing, broth, casseroles, soups and stews
• Pizza with any topping
• Soft cheeses (cream, mozzarella, ricotta, cottage, brie and similar), shredded cheese, low-fat cheese
• Milk, cream, sour cream, buttermilk, yogurt, soy milk, eggnog; opened baby formula
• Fresh eggs, egg dishes and egg products, custards, puddings and quiche
• Cut fresh fruit and cut fresh vegetables; cooked vegetables; pre-cut, pre-washed greens
• Cooked pasta, rice and potatoes; pasta salads; fresh pasta; potato salad
• Opened creamy dressings, opened spaghetti sauce, fish sauce and oyster sauce
• Refrigerator biscuits, rolls and cookie dough; cream-filled pastries; pies with egg or milk filling
• Opened mayonnaise, tartar sauce or horseradish, if above 50°F for more than 8 hours

Keep

• Hard cheeses (cheddar, Colby, Swiss, Parmesan, provolone, Romano), processed cheese, grated Parmesan in a can or jar
• Butter and margarine
• Uncut fresh fruit and vegetables; fresh mushrooms, herbs and spices
• Opened fruit juice and opened canned fruit; dried fruit
• Peanut butter, jelly, mustard, ketchup, olives, pickles, relish, soy and barbecue sauce, opened vinegar-based dressing
• Bread, rolls, cakes, muffins and tortillas; waffles, pancakes and bagels
• Fruit pies

Some items that feel fine are on the discard list: soft cheese, cut fruit and cooked pasta. The chart applies to food above 40°F for more than 2 hours; if you don't know the temperature, treat it as exposed.

Frozen food: keep, refreeze or discard

FoodSafety.gov says food in the freezer may be safely refrozen if it still contains ice crystals or is at 40°F or below, though quality may suffer. In the chart:

Note that the chart treats ice cream and frozen yogurt as discard even with ice crystals. Quality loss is real when you refreeze, but safety comes first.

After the power comes back

• Check the freezer first. If items still hold ice crystals, follow the table above.
• Check the fridge temperature. Discard what the chart says to discard. Don't taste to test.
• Give the fridge time to cool down and confirm 40°F or below on the thermometer before you rely on it again. That is our advice, using the same 40°F line the sources use.
• Turn off or disconnect sensitive appliances during an outage; Ready.gov warns that power may return with surges or spikes that can damage them.

Medicines and baby formula

The CDC says that when power is out for a day or more, you should throw away medication that should be refrigerated unless the label says otherwise. If a life depends on a refrigerated drug and it has been at room temperature, use it only until a new supply is available, and replace refrigerated drugs as soon as possible. Ask your pharmacist or doctor about your specific medicine before an outage, not during one. FoodSafety.gov lists opened baby formula as discard.

Water

When power goes out, water purification systems may not be working fully. The CDC says safe water for drinking, cooking and hygiene includes bottled, boiled or treated water, and your local health department can say what's recommended in your area. Keep stored water with your food supplies.

Don't use a generator or stove unsafely to save food

Never run a generator inside a home or garage, even to save the freezer. The CDC says to keep generators more than 20 feet from windows, doors and vents, and not to use a gas range or oven for heat. See generator carbon monoxide safety for the placement rules. When the choice is food or safety, the food is replaceable.

Quick keep-or-toss checklist

Apartment dwellers can find a plan for tight spaces and small batteries in renters' backup power. If you live on the Gulf Coast, see the hurricane outage checklist for a multi-day plan, and the Alabama outage checklist for utility numbers. Many renters policies and homeowners policies treat spoiled food differently; check your own policy if you want to claim.