Fixit: How long will food keep if power fails?

By Karen Youso, Star Tribune

Last update: September 18, 2007 - 4:40 PM

Featured comment

My power was out for 9 hours. everything in freezer part of refrigerator was all soft. report says it last a day?

Q How long will food keep in a refrigerator and freezer when there is an electrical failure, the inside house temperature is 85 degrees and the doors to the refrigerator are not opened? Is there a "rule of thumb" to follow?

A Generally, food will stay safe in the refrigerator for four to six hours. When the power goes out, check the time. It is important to know how long your power has been out. Do not open and close the door to check food. Placing block ice on a tray or pan in the refrigerator will help to keep it cool for about a day. Move as much food as possible to the freezer.

Realize that, even if the food looks and smells fine, it may not be safe to eat. Bacteria that causes food poisoning does not make food look any different. It will not smell bad or look odd. If the food has been warm, above 40 degrees, for more than two hours, throw it away. Do not taste the food to see if it is still good.

Food in the freezer section of a refrigerator will stay frozen for about a day. If a stand-alone freezer is full, food will stay frozen for about two days, one day if half full. Again, do not open the door to check food.

Dry ice can keep food frozen a couple of days. Place cardboard on top of the food and put the dry ice on top of the cardboard. Handle it with gloves and have the room well ventilated. CAUTION: Be certain the room has good ventilation. Carbon dioxide gas can accumulate and cause loss of consciousness and asphyxiation.

If power will be out more than a few days, transfer foods as quickly as possible to another freezer or a commercial locker.

If you know the power may go off, turn the freezer control to the lowest temperature. If you might have several days without power, act quickly. Get dry ice and put it in the freezer before food starts to thaw. Dry ice is listed in the yellow pages of phone directories. (Locate a source for dry ice before the power goes out to reduce your stress.)

If the food still contains ice crystals when the power returns, it can safely be refrozen. If there are no ice crystals but the food is cold (40 degrees or below), treat it as if it had been in the refrigerator, and use within the recommended time. If the food is warm (above 40 degrees), toss it.

Be especially careful with protein foods.

If there's a rule of thumb for food safety, it is: When in doubt, throw it out.

From extension services at the Universities of Illinois and Minnesota

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