Water & Food
How to Keep Food Safe During a Power Outage
The 4-hour and 48-hour rules, what to throw out, and how to prepare your fridge before the lights go out.
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Quick answer
Keep the refrigerator and freezer doors closed. An unopened refrigerator keeps food safe for about 4 hours. A full freezer holds its temperature for about 48 hours, and a half-full freezer for about 24 hours. Throw out perishable food such as meat, dairy and leftovers that has been above 40°F for more than 2 hours. When in doubt, throw it out.
Before the outage
- Put appliance thermometers in your refrigerator and freezer. The fridge should be at 40°F or below and the freezer at 0°F or below.
- Freeze containers of water, ice packs and items you won't need right away. A fuller freezer stays cold longer.
- Know where you can get dry ice or block ice, and keep a cooler or two ready.
- Group frozen foods together so they stay cold longer.
During the outage
Keep the doors closed as much as possible. According to USDA and FoodSafety.gov guidance:
| Appliance | Stays safe (doors closed) |
|---|---|
| Refrigerator | About 4 hours |
| Full freezer | About 48 hours |
| Half-full freezer | About 24 hours |
If the power will be out longer than 4 hours, move milk, meat, eggs and leftovers into a cooler packed with ice. A portable power station can also keep a refrigerator running for a while; see our power station vs. generator guide.
After the power comes back
- Throw out perishable food that has been above 40°F for 2 hours or more.
- Frozen food that still has ice crystals or reads 40°F or below can be refrozen or cooked.
- Never taste food to decide whether it's safe. Bacteria that cause illness don't always change the smell or look of food.
- Throw out any food that touched flood water.
Medications that need refrigeration, like insulin, have their own rules. Check the label or ask your pharmacist, and keep an insulated medication cooler ready.
Our picks
Products we'd consider for our own kits, chosen for reputation and fit. We don't accept payment for placement. Prices and availability are set by Amazon sellers and change often.
- Best for: Knowing what's safeView on Amazon: Taylor Refrigerator/Freezer Thermometer (opens in a new tab)
Taylor Refrigerator/Freezer Thermometer
An inexpensive appliance thermometer that tells you whether food stayed cold enough.
- Best for: Multi-day iceView on Amazon: YETI Tundra Hard Cooler (opens in a new tab)
YETI Tundra Hard Cooler
A heavily insulated cooler that holds ice for days, good for moving food during long outages.
- Best for: Budget pickView on Amazon: Coleman Xtreme Wheeled Cooler (opens in a new tab)
Coleman Xtreme Wheeled Cooler
A large wheeled cooler with solid insulation at a lower price.
- Best for: Refrigerated medicineView on Amazon: FRIO Insulin Cooling Case (opens in a new tab)
FRIO Insulin Cooling Case
An evaporative cooling wallet that keeps insulin cool without ice.
Build your personalized kit
Get suggested quantities for your household, pets and local hazards in about two minutes.
Open the Bunker Kit BuilderOfficial sources
- FoodSafety.gov (opens in a new tab)
- Ready.gov: Power Outages (opens in a new tab)
- Ready.gov: Food (opens in a new tab)
This guide is general information based on public guidance from the agencies above. It is not medical or professional advice, and The Blackout Bunker is not affiliated with any government agency. Always follow instructions from local officials.
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