Food Safety Food Handler Food Manager

Power Outages: How Long is Food Safe When Your Business Goes Dark?

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Trust20 Contributors • 10 minute read

As much as we don’t like to think about it, it’s time to face the facts–power outages are becoming more frequent, and they’re probably not going to go away any time soon.

In fact, between 2013 and 2021, the frequency of power outages increased, on average, from 1.2 to 1.4 events per customer each year, according to Scientific American.1 Not only that, but major power outages are lasting much longer than they did, too.2

While there’s certainly some debate to be had about what’s making these outages more severe and longer in duration, the reality is that power outages of any length or extent have a major impact on foodservice establishments.

Even a few hours without power, particularly during hot weather, can spell disaster for foodservice professionals who are trying to keep hot food hot and cold food cold

By being aware of the inherent risks and taking steps to ensure food safety during power outages, we can plan ahead for just about any emergency.

We won’t keep you in the dark any longer. Here’s what you need to know.

How Long is Food Safe with No Power?

How to Plan Ahead for Power Outages

Dealing With Power Outages When They Happen

What to Do After the Power Comes Back On

How Long is Food Safe with No Power?

Let’s start by addressing the elephant in the room. If the power goes out, when does the clock start ticking? In other words, how long does it take for food to become unsafe once it’s no longer being heated or cooled?

In general, food that is stored in a refrigerator should be able to remain at a cool temperature for about four hours–but that’s only if you keep the door closed. 

Refrigerators are designed to maintain a consistent temperature that keeps food safe for consumption. That’s the good news.

The bad news is that if the door is opened frequently, the temperature will fluctuate, and the food will not remain safe for quite as long. 

As for a freezer, food that’s solidly frozen will remain so for up to 48 hours with no power–again, as long as the door remains closed.3

There’s some variability to this, however. A partially full freezer won’t stay cold quite as long as one that’s completely full, nor will a freezer that has some food items that haven’t had time to freeze all the way through.

There are a few other factors to consider here, too, such as the type of food being stored and its initial temperature. Raw meat and dairy products are more susceptible to spoilage and should be more carefully monitored. 

How to Plan Ahead for Power Outages

Unfortunately, there’s no way of knowing when a power outage is on its way. Sure, looking at weather forecasts might give you an idea of when a nasty thunderstorm is on the way and might knock out power for an hour or two.

But what about when the grid is overloaded, and power is shut off for several days? Nine times out of ten, there’s no good way to predict when your restaurant or other foodservice establishment might lose power.

Because of this unpredictability, it’s a good idea to have a plan in place for what you (and your team) should do if and when the power goes out. While your plan might not work for power outages that last for several days at a time, these tips will at least give you some peace of mind for the short term.

Keep Thermometers in All Refrigerators and Freezers

First, keep thermometers in all of your refrigerators and freezers–and use them. This will let you keep an eye on the temperature of the items inside and make sure they’re at the correct temperature for food safety (a good precaution to be taken regardless of power outage).

If you do have an outage, check the temperatures of your refrigerators and freezers immediately. Shut the door, then don’t check again until the power has come back on (remember, opening those doors too many times will cut down on how long you can safely store that food). 

After the power returns, check the temperature again. Discard any items that have been exposed to temperatures above 40°F for more than two hours.3

Group Foods in the Refrigerator and Freezer

Another tip for planning ahead for power outages is to group food products inside based on type. Pack items closely together so they maintain a colder temperature for a longer period of time.

Keep the Freezer Full

Another useful tip is to keep your freezer full as much as possible. This is because a full freezer retains its temperature longer than a partially filled one. 

If you’re not able to keep your freezer completely full, fill empty spaces with frozen jugs of water. This will keep the temperature low and prevent your food products from thawing out too quickly.

Cold air will escape through empty spaces, so the frozen jugs will help keep things colder until the power comes back on. 

Freeze Refrigerated Items You Don’t Need Immediately

When the power goes out, the temperature inside refrigerators and freezers will start rising, especially in a hot kitchen. To plan ahead for this, freeze any refrigerated items you don’t need in the next few days.

This will not only keep them safe to eat for longer (even if a power outage doesn't happen), but it will also fill up some of those empty spaces in the freezer we want to get rid of, as previously mentioned.

Keep Large, Insulated Coolers and Frozen Gel Packs Available

One final tip to help you mitigate the risks of power outages is to keep some large, insulated coolers and frozen gel packs on hand.

These can help keep perishable food items at safe temperatures until the power is restored (particularly if your refrigerator is warming up more quickly than you’d like).

Dealing With Power Outages When They Happen

Now that you know what to do in advance of a power outage, what should you do when things really go sideways? In other words, what should you be doing when the lights go off, and you don’t know how long they’ll stay off?

Here are some tips.

Note the Time the Power Outage Started

Keep track of when the power outage occurred. This will help you assess the level of risk to the food in your refrigerators and freezers and determine how long they have been without power.

You can use this information to make informed decisions about what food can be salvaged and what needs to be discarded when the power comes back on. 

Keep the Refrigerator and Freezer Doors Closed

When the power goes out, it's natural to want to check on the food in the refrigerator and freezer. Resist that urge!

As we mentioned earlier, every time you open the refrigerator or freezer door, you let warm air in, which can cause the temperature to rise rapidly. This can shorten the shelf life of the food inside and make it unsafe.

Don’t Place Hot Food in Refrigerators or Freezers

This next mistake is all too common, and we really can’t blame you. It’s natural to want to pop a pan of hot food in the fridge, thinking you’ll cool it down since you can’t serve it right away or finish cooking it once the power has clicked off.

Unfortunately, this is a major misstep. When you put hot food in the refrigerator or the freezer, it will rapidly elevate the temperature inside, putting the safety of the other food items inside at risk. Your 48-hour safety window we mentioned before has just been cut in half–if not more.

Discard Food Products That Are Only Partially Cooked

As frustrating as it can be, if you were working on some prep before the power outage, you’ve got to throw out any of the products that were a part of your hard work (we’re so sorry).

Bacteria grows quickly in perishable foods, and since food that you’re still preparing is likely still in the temperature danger zone, you’re putting yourself and others at risk by trying to salvage it. 

Consider Getting Dry Ice if Power Will Be Out for a Long Time

If the power outage is going to last for a prolonged period of time, consider picking up some dry ice. This will help keep the temperature cold even without electricity. Dry ice has a temperature of -109.3 degrees Fahrenheit, making it the perfect solution to maintain safe food temperatures for an extended period.4

Just keep in mind that dry ice can be hazardous in enclosed spaces and should therefore be used with caution. 

Food in the Door and in the Front of the Freezer Will Defrost First

Remember that food in the door or front of the freezer or refrigerator will warm up and defrost first. Move it to the back of the freezer when you do your initial (and only) temperature check. Whenever possible, try not to store food in the door at all, especially if it’s highly perishable (like meat).

Don’t Place Perishable Food Out in the Snow 

One common mistake that foodservice professionals in cold climates make is putting refrigerated or frozen food outside during a power outage. They pop a few pans of food in a snowbank, assuming (and who can blame them?) that since it’s well below freezing outdoors, the food will be just as safe (if not more so) out there than it was inside.

The problem with this is that outdoor temperatures can vary, especially if there’s sun. Not only that, but it’s an unsanitary environment for food. What happens if a bird flies by and leaves behind its droppings all over the pot of chili you just prepared? 

Better safe than sorry–keep the food inside. 

What to Do After the Power Comes Back On

When the power finally comes back on, it’s only natural to want to hoop, holler, and jump for joy (especially if it's been out for a long time).

However, there are a few steps you need to take before you start celebrating.

Don’t Taste Food to Determine Safety

First, don’t ever taste food to decide whether it’s safe to eat. This can be tempting, but it’s best to err on the side of caution. If you’re not sure, throw it out. 

Know What to Toss and What to Keep

Have a checklist of what to toss and what to keep if the power has been out for longer than four hours.

Any meat, poultry, fish, eggs, luncheon meats, casseroles, soups, stews, mixed salads, dairy products, cut fruits and vegetables or cooked vegetables, batters and doughs, and anything that may have been contaminated by dripping juices from meat or poultry, should be discarded.5

The same goes for any food with an unusual texture, odor, or color–regardless of how long it was frozen or kept chilled, it should not be consumed.

In most cases, there are still some foods that can be salvaged after an outage. Those that don’t technically require refrigeration are obviously safe. These include food products like butter, hard cheese, dried fruit, and whole fruits and vegetables.

Similarly, frozen foods that have thawed but contain ice crystals are usually still okay, as are foods that haven’t dropped below refrigerated temperatures in the freezer. These can usually still be refrozen without a risk of contamination, though the quality of the food may decline. 

Get Rid of Spoiled or Questionable Food

Get rid of any questionable food immediately. Again, don’t taste it. Just toss it in the trash and move on.

Remove the Shelves and Crispers, Then Wash Everything Thoroughly

When the power goes out and food starts to thaw, you may find a mess in your refrigerators and freezers after the fact. Meat, in particular, has a tendency to leak blood and juices all over the place when it’s thawed rapidly.

Take the time to thoroughly clean and disinfect all surfaces, including shelving and crisper drawers. Wash everything with hot, soapy water.6

If There Are Odors, You May Need to Do a Deep Clean

If you notice any unpleasant odors after opening back up after a power outage, you may have to buckle down and do a deep clean. There may be areas of the kitchen that are contaminated with juices or bacteria from thawed foods. 

Make Sure Any Food You Prepare is Still Cooked to a Safe Minimum Internal Temperature

Finally, when you open back up, make sure you take the time to follow all normal cooking procedures as they relate to temperature control.

Get rid of any foods that have been exposed to unsafe temperatures and use a food thermometer to make sure foods are cooked to the proper internal temperature. This is particularly important for meat, eggs, and fish

Final Thoughts

Making sure your customers are served safe food should be your top priority. This responsibility can become increasingly challenging during power outages, but it can be done.

The best course of action is to prepare ahead of time by properly training your staff.

Trust20 offers a comprehensive range of food safety products that can provide you and your staff with the skills and knowledge you need to handle power outages with grace. Although they can be frustrating, power outages can be planned for. From understanding food handling techniques and temperature controls to identifying signs of spoilage, Trust20’s products cover it all.

Prepare for the worst and hope for the best–Trust20’s got you covered.

Start Trust20's Food Manager Program today.


  1. Scientific American: Increasing Power Outages Don't Hit Everyone Equally
  2. Business Insider: Get Ready: More Blackouts Are Coming
  3. FDA: Food and Water Safety During Power Outages and Floods
  4. CDC: Food Safety for Power Outages
  5. U.S. Department of Health & Human Services: Food Safety During Power Outage
  6. USDA: Keep Your Food Safe During Emergencies: Power Outages, Floods & Fires