Home power outages can be inconvenient and wasteful. fridges and freezers can only keep food safe for short periods of time, therefore if a power outage is expected to exceed a few hours, precautions must be made concerning the safety of food items kept in the fridge or freezer. When in doubt, throw it out. Nonperishable items are the safest to consume during power outages.
Full refrigerators can safely preserve food for four to six hours without power as long as the internal temperature does not exceed 4.44 degrees C (40 degrees F). A refrigerator that is half or partially full will not preserve the food as well as one that is full. The length of preservation also depends on how frequently you open the door; if possible keep the door closed for the duration of the power outage.
A full freezer that is kept closed at all times can preserve frozen items for up to 48 hours. If the freezer is only half or partially full, frozen food items will keep for only about 24 hours. The temperature inside of the freezer must remain below 0 degrees C (32 degrees F) or items will begin to thaw.
Keeping the doors of both the refrigerator and freezer shut will help preserve the food longer. If the power is going to be out for an extended period of time, move all items stored in the door to the core of the refrigerator and purchase blocks of ice or dry ice if available. A 22.7 kg (50 lb) block of dry ice can keep food safe in the freezer for an extended 48 hours. Dry ice placed in the refrigerator will also extend the life of the food as long as it is placed in a secure bag or styrofoam carton.
If in doubt of the safety of thawed or warming food, throw it away immediately. Discard all frozen food that begins to thaw including meats, fish, poultry and anything that comes into contact with its juices. Dairy items in the refrigerator such as milk, cheese and yoghurt should also be discarded if the temperature reaches above 4.44 degrees C (40 degrees F). Any meat or poultry items should be consumed immediately after two hours and discarded after four hours of power outage. Inspect all other items for safety by examining the smell and texture. Discard any items that come into contact with thawing meat or dairy liquid and clean up thoroughly.