Dealing with Power Outages
Plan Ahead: In preparation for bad weather, fill freezer bags with ice for ice packs or purchase freezer-pack inserts. Have coolers available and easily accessible; styrofoam ones work great. Have a calibrated food thermometer for checking the temperature of your potentially hazardous food. Before an emergency occurs, find out where to buy blocks of ice or dry ice. Before an expected storm, turn refrigerators and freezers to the coldest settings.
When the power goes out, unplug the freezer and refrigerator and other appliances, to protect them from power surges when the power returns. Make sure everyone in your household knows not to open the refrigerator or freezer doors. Keeping the doors closed will keep the food cold for a longer period of time. Wrap the refrigerator or freezer in blankets to create extra insulation. Make sure blankets don’t touch the compressor. If power possibly will be off for more than 2 to 4 hours, re-pack refrigerated items into coolers with plenty of ice.
Depending on the size of the freezer, how full it is, and how well insulated it is, items in it potentially can stay frozen for 2 to 4 days. A full freezer (operating at 0°F) will keep foods frozen for about 48 hours if the doors stay closed. A half-full freezer can only be expected to keep food frozen for a maximum of 24 hours. For extended power outages use blocks of dry ice in the freezer. A fifty pound block of dry ice will keep the contents of a full 18 cubic foot freezer frozen for 2 days. Remember to wear gloves or use tongs when handling dry ice.
When the power returns, check the internal temperatures of all perishable foods with a calibrated food thermometer. Discard any perishable food that has been above 40°F for more than 2 hours. The following recommendations apply to food safety in any power outage.
Use a Thermometer: Keep an appliance thermometer in the refrigerator and freezer at all times to see if food is being stored at safe temperatures (34°F to 40°F for the refrigerator; 0°F or below for the freezer). Temperature is critical to the safety of foods in the refrigerator and freezer. Most foodborne illnesses are caused by bacteria that multiply rapidly at temperatures above 40°F.
Leave the Freezer Door Closed: A full freezer should keep food safe about two days; a half-full freezer, about a day. If freezer is not full, group packages together quickly. Group meat and poultry to one side or place on separate trays to keep their juices from contaminating other foods if they thaw. Then avoid opening the freezer door to prevent the cold air from escaping.
Add Ice or Dry Ice: Add bags of ice or dry ice to the freezer if the power is likely to be off for an extended time. Use three pounds of dry ice per cubic foot of freezer space. The temperature of dry ice is -216°F, so use rubber gloves or tongs when handling it. Wrap dry ice in brown paper for longer storage, and separate it from direct food contact with a piece of cardboard. Fill a partially empty freezer with crumpled newspaper to cut down on air currents which cause dry ice to dissipate. Provide adequate ventilation for carbon dioxide in areas where dry ice is used. Do not cover air vent openings of freezer.
Refrigerated Items: These foods should be safe as long as the power is out no more than four to six hours. Discard any perishable food that has been above 40°F for two hours or more and any food with an unusual odor, color or texture. Leave the door closed; every time it is opened, cold air escapes and causes the foods inside to warm to unsafe temperatures. If the power will be off more than six hours, transfer refrigerated perishable foods to an insulated cooler filled with ice or frozen gel packs. Keep a thermometer in the cooler to be sure the food stays at 40°F or below.
Never Taste Food to Determine Its Safety: Some foods may look and smell fine. However, if they have been at room temperature longer than two hours, bacteria that cause foodborne illness can begin to multiply very rapidly. Some bacteria produce toxins which are not destroyed by cooking and can cause illness.
Power Out Chart
Use the following to decide which foods are safe to eat when the power is restored.
Discard: The following foods should be discarded if kept over two hours at above 40°F.
- Meat, poultry, fish, eggs and egg substitutes - raw or cooked.
- Milk, cream, pasteurized yogurt and soft cheese
- Casseroles, stews or soups
- Lunch meats and hot dogs
- Creamy-based salad dressings
- Custard, chiffon or cheese pies
- Cream-filled pastries
- Refrigerator and cookie dough
- Discard open mayonnaise, tartar sauce and horseradish if above 50°F for over eight hours.
Save: The following foods should keep at room temperature a few days. Still, discard anything that turns moldy or has an unusual odor.
- Butter or margarine
- Hard and processed cheeses
- Fresh fruits and vegetables
- Dried fruits and coconut
- Opened jars of vinegar-based salad dressings, jelly, relish, taco sauce, barbecue sauce, mustard, ketchup, olives and peanut butter
- Fruit juices
- Fresh herbs and spices
- Fruit pies, breads, rolls and muffins
- Cakes, except cream cheese-frosted or cream-filled
- Flour and nuts
Refreeze: Thawed foods that still contain ice crystals may be refrozen. Thawed foods that do not contain ice crystals, but have been kept at 40 °F or below for two days or less, may be cooked, then refrozen or canned.
For more information about food safety in an emergency, see the following fact sheets:
- HGIC 3760 Food Safety in Power Outages
- HGIC 3780 Food Safety in Freezer Failure
- HGIC 3800 Food Safety in Hurricanes & Floods
- HGIC 3820 Food Safety after a Tornado
- HGIC 3840 Food Safety after a Fire
HGIC 3760 Food Safety in Power Outages by P. Schmutz and E.H. Hoyle Clemson Home and Garden Information Center
Preparing for Power Outages. A.M. Oesterle and E.L. Andress National Center for Home Food Preservation. http://nchfp.uga.edu/tips/summer/power_outages.html, Revised May 2013