Food Safety During a Power Outage: How Long Will Food Last Without Power?
Last year's winter storm and power outage in Texas has disaster preparedness at the top of everyone's minds, particularly in regard to food safety. The news was full of the creative lengths that some Texans went to in order to keep food from spoiling.
"Creativity" isn't something you want to see related to food safety, however. If you want to avoid contracting a serious foodborne illness in the middle of a disaster, it's a good idea to understand tried and true methods that experts recommend for keeping perishables safe during a power outage.
Below, you'll find guidelines and tips to keep your household food supply safe during an extended power outage, just in case it happens again.
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How Long Can Food Last Without Power?
How long food will stay a safe temperature once the power goes out depends on a lot of factors, but the big one is keeping the refrigerator and freezer doors closed as much as possible.
How Long Will A Fridge Stay Cold Without Power?
For food safety purposes, a refrigerator needs to remain at 40°F or above. During a power outage, a typical refrigerator will keep food cold for approximately 4 hours if it's never opened.
A time-based guess is risky, however. It's better to have thermometers that can tell you for certain when food enters the danger zone.
How Long Will A Freezer Stay Cold Without Power?
How long food lasts in a freezer depends on how full the freezer is. If it's packed full and the door stays closed, a freezer will keep its temperature for around 48 hours. At half full, it will stay cold for roughly 24 hours.
How to Prepare Your Refrigerator and Freezer for a Power Outage
Emergency preparation and planning can make an enormous difference for food safety in a power outage. It can mean the difference between having to restock your fridge from scratch and making it through unscathed.
Supplies to Have On Hand
Purchasing a few things during good times will save you from scrambling to find them on the shelf just before a predicted power outage.
In the interest of food safety, consider purchasing:
- Appliance thermometers. You'll need one for the fridge and one for the freezer. You can get the simpler versions for under $10, or splurge for sensors that connect wirelessly to a outside-appliance display. These can even be handy outside a general power outage – for example, if your fridge breaks down.
- Coolers. If your power is out for more than four hours, you'll want well-insulated coolers to keep refrigerated food below 40°F. You're much more likely to keep food at a safe temperature in a packed cooler than in the empty space of your fridge.
- Cold Sources. You'll need ice or cold packs to keep those coolers at the right temperature.
- Cooking Alternatives. If all of your cooking appliances are electric, you need to have some kind of plan for long power outages. Maybe that's a stockpile of non-perishable food that can be eaten as-is, but you'll probably want some way to cook perishables before they can go bad. That may involve an emergency generator or even a well-maintained fireplace, but for most people, a gas-powered camp stove or something similar will do. Just make sure you understand the necessary safety precautions for your equipment.
What to Do Before a Possible Power Outage
If you're lucky enough to get forewarning of a power outage, a few preparatory steps can help you manage food temperature as effectively as possible.
- Install the Appliance Thermometers. The best place to put them will be the warmest spot, so you can guarantee everything in the compartment is colder than the reading – that means near or in the door. Make sure batteries are fresh, if applicable.
- Prepare Your Cooler & Cold Sources. Locate and clean your coolers. Put all gel packs and cold sources in the freezer and/or stock it with ice cubes.
- Pack Your Freezer. Remember, freezers stay cold longer if they're completely full, and any freezer will stay cold much longer than the fridge. Move any items that can be frozen and that you may not need immediately into the freezer. That includes milk and raw meat.
- Make Note of What You Have and Where. We mentioned that you'll need to keep the refrigerator and freezer sealed as much as possible. That means writing down (on paper!) what you have in each compartment for meal planning and quick retrieval.
- Crank Down the Temperature. If you're able to control fridge and freezer temperature, set them as low as possible ahead of the potential outage. The colder the compartments are before the power goes out, the longer they'll stay in the safe temperature zone.
- Freeze Containers of Water. Just remember not to fil them all the way – water expands as it freezes. This has several purposes. It can fill out the empty spots in your freezer, act as another cold source for the coolers (just make sure those containers will fit), and they can serve as a source of potable water once they melt.
- Scout Sources of Dry/Block Ice. In case the power outage outlasts all your supplies at home, it can be helpful to know ahead of time where you can go to buy dry ice or block ice. Your internet may be out, so make a note ahead of time.
How to Make Food Last During a Power Outage
The most important food safety precaution is to keep refrigerator and freezer doors closed as much as possible. At the same time, you'll want to eat anything in the fridge first, since it's the most vulnerable to going bad. Just retrieve items quickly.
Resist the urge to check temperatures too often. Checking the fridge for the first time less than 4 hours after power loss, then every 1.5 to 2 hours after that, should be often enough.
Once the fridge thermometer starts to creep up near 40°F, start transferring items into your coolers with add cold sources from the freezer. Ideally, you'll have enough cold sources in the freezer to switch out as the coolers start to approach 40°F, but just like the fridge, you'll want to keep the coolers sealed as much as you can.
How to Check if Food is Safe to Eat During and After the Outage
Food safety professionals call certain foods "Time and Temperature Control foods." They pose a special risk of pathogen growth if they're kept at an unsafe temperature for an unsafe amount of time.
If, at any point, you know or suspect that meat, poultry, seafood, milk, eggs, or other perishables have spent more than 4 hours above 40°F, you must discard them or risk becoming very sick. Thorough cooking won't make them safe. Even 2 hours can be a risk, but the higher the temperature, the faster it will become unsafe.
If the storage temperature was borderline, you need to check the temperature of individual foods with a meat thermometer or something similar before you decide they're safe to eat. Foods that never get above 45°F should be safe but cook them thoroughly and eat them as soon as possible.
Check the freezer temperature when power is restored (or has been out for more than 24-48 hours). If the freezer contents never rise above 40°F, they're safe to re-freeze. If the food still contains ice crystals, that's a good sign.
You can't rely on appearance or odor alone to judge safety. While those clues can tell you if the food is bad, they can't guarantee that the food is still good. Most importantly, never taste food to check for spoiling.
Food Safety in Good Times
While people in the food industry train for food safety and take precise precautions on a daily basis, most folks don't consider it unless something goes wrong.
It's important to know the basics, however. You might be surprised to discover that you're risking food poisoning in ways you wouldn't have guessed! Check out our blog article on how to purchase, handle, and cook food safely at home.