Keeping food cold when the power is out
Without power, a full upright or chest freezer will keep everything frozen for about 2 days. A half-full freezer will keep food frozen 1 day.
If power will be coming back on fairly soon, you can make the food last longer by keeping the door shut as much as possible.
If power will be off for an extended period, take food to friends' freezers, locate a commercial freezer or use dry ice.
Your refrigerator-freezer combination
Without power, the refrigerator section will keep food cool 4 to 6 hours depending on the kitchen temperature.
A full, well-functioning freezer unit should keep food frozen for 2 days. A half-full freezer unit should keep things frozen about 1 day.
Block ice can keep food on the refrigerator shelves cooler. Dry ice can be added to the freezer unit. You can't touch dry ice and you shouldn't breathe the fumes, so follow handling directions carefully.
What to do about thawed food
Food still containing ice crystals or that feels refrigerator-cold can be refrozen.
Discard any thawed food that has risen to room temperature and remained there 2 hours or more. Immediately discard anything with a strange color or odor.
- Kitchen Companion: Your Safe Food Handbook, USDA Food Safety and Inspection Service, 2008
Revised 2010 by Suzanne Driessen