Keeping food safe when the power goes out

By Beth Cecil
Owensboro Health Healthpark dietitian

Editor's Note: This article was written in September 2008 after winds from Hurricane Ike disabled power throughout the Owensboro area.

Sunday, September 14th is a day that will remain etched in our memories for years to come. The windstorm that swept through Owensboro that day affected practically everybody in one way or another.

Whether you lost shingles, your entire roof, limbs, trees or branches, it seems that one of the biggest challenges many of you likely had to face was figuring out how to function with the loss of electricity, in some cases for days.

While I was fortunate enough to be without power for only about 6 hours, my parents were among those who lost power for several days. By noon on Monday, I found myself taking coolers to their house and helping my mother transport the contents of her freezer to my house for storage in our deep freeze.

I would imagine however that thousands of folks throughout the city ended having to either quickly use or throw away a lot of food during the following week. This has to be especially painful considering the rising food costs today.

A reader wrote in to me with some very good questions about keeping food safe during a power outage such as this. She asked about how long food will remain safe, how you know what to pitch and questions about salvaging frozen foods.

Following her suggestion, I thought I would share some guidelines for keeping food safe during emergency situations.

Probably the number one rule during a power outage, as I am sure you have heard before, is to keep your refrigerator and freezer doors closed as much as possible in order to maintain the cold temperature. An unopened refrigerator should keep food at a safe temperature for about four hours. A full freezer will maintain the temperature for about 48 hours and one that is half full should hold for about 24 hours. If are able to get ice or dry ice, you can maintain the temperatures for longer.

I do know that these temperature guidelines can vary, which is why I think it is essential to keep a thermometer in both your freezer and refrigerator. This is a good idea anytime, but can be especially useful in emergency situations. These will always show the internal temperatures no matter how long the power has been out.

The refrigerator should normally remain at 40° F or below. Any perishable food (milk, meat, poultry, fish products, eggs and leftovers) that has been above 40° F for more than 2 hours will need to be discarded. If the power has been off at least 4 hours, quickly open the door every hour or so in order to monitor the temperatures.

As for the freezer, if you do have a thermometer and the temperature has remained at 40° F or below, the food is safe and may be refrozen. If you don’t have a thermometer, take a look at each item individually. The presence of ice crystals will indicate that it is safe to refreeze. Note that partial thawing and refreezing could potentially reduce the food’s quality, but as long as the temperature guidelines are followed, it will still be safe. Do not rely on odor or appearance of foods, and certainly don’t taste them for safety. However, if a food does have an odd or foul odor, I would probably be inclined to pitch it.

There are some foods that may remain safe even if held above 40° F for more than 2 hours. These include hard, processed and grated cheeses such as parmesan, butter, margarine, fruit juices, canned and dried fruits, raw vegetables, peanut butter, jelly, relish, mustard, ketchup, olives, pickles, barbecue, Worcestershire and soy sauces, breads, cakes, muffins, pancakes, waffles, tortillas, and vinegar based dressings.

Additionally, there are some foods that can be refrozen even after thawing including hard cheeses, breads, rolls muffins, cakes, pie crusts, nuts, bagels, waffles and pancakes.

Hopefully, you won’t need these tips for a long time to come, but it is better to be prepared. And always remember that when in doubt throw it out!

For more information, you can visit the USDA’s Department of Food Safety and Inspection Service website at