Epidemic! The Natural History of Disease.  At the San Diego Natural History Museum

Safety From Food-borne Illnesses
Food safety in the event of a power outage

Due to on-going declarations of electrical emergencies in California, the San Diego County Department of Environmental Health provides recommendations on food safety to prevent food-borne illnesses at homes and businesses in the event of a power outage.

General Precautions for Food Safety
If There Is an Advance Warning of an Outage
How Long Food in Freezer Stays Good
Evaluate Potentially Hazardous Foods
When in Doubt, Throw It Out
Cook Foods to Minimum Temperatures
Contacts for Further Information


General Precautions for Food Safety

  • Keep refrigerator and freezer doors closed. Keep potentially hazardous foods, such as meat or poultry, chilled to 41°F or less.
  • Do not place hot or unrefrigerated foods in the refrigerator once the power has gone out. It will raise the temperature inside the unit. Chill food with ice baths as needed. Discard any foods that were prepared prior to the power outage that were not rapidly cooled.
  • Keep meat and poultry items separated from other foods so that if they begin to thaw, their juices will not drip on to other foods.
  • Discard any thawed foods that has risen to room temperature and remained there for 2 hours or more.
  • Kitchen ventilation units will shut off during power outages. Be advised that there have been reports of smoke, heat, and grease emissions setting off alarm and fire suppression systems.


If there is advance warning of a power outage and the outage is anticipated to last:

  • 2 hours or less, no special precautions are needed except to keep the doors to the freezer and refrigerator closed as much as possible.
  • More than 4 hours, try to move foods that must be refrigerated to the freezer, as space will allow.
  • More than 6 hours, you may need to use, dry ice, block ice, or bags of ice in order to maintain potentially hazardous foods (foods that are labeled "keep refrigerated" or those items listed below) at 41°F. Be especially careful when handling dry ice and do not touch it directly with bare skin or breathe the fumes directly.


How long does food in a freezer stay good during power outages?

  • A full freezer without power will stay frozen for about 2 days.
  • A half-full freezer will keep food frozen 1 day.
  • If the freezer is not full, quickly group packages together so they will retain the cold more effectively.


Evaluate All Potentially Hazardous Foods When the Power Comes Back On

Bacteria can multiply rapidly on potentially hazardous foods that have been at room temperature for more than 2 hours. In addition to the general precautions on the previous page, the following tips are helpful to remember during picnics, parties, and other events as well where foods that should be refrigerated are left at room temperature for a prolonged period of time.

  • Discard any foods that have been contaminated by raw meat juices and immediately discard anything with a strange color or odor.
  • If potentially hazardous foods were at room temperature or above when the power went out, they should be rapidly cooled to 41°F using an ice bath prior to placing in any refrigerator or freezer.
  • If the food has not reached 41°F within 6 hours it should be discarded.
  • Thawed foods that are at 41°F or below should be used as soon as possible.
  • Do not refreeze thawed foods.


When in doubt, throw it out!

Discard the following potentially hazardous foods if kept above refrigerator temperature (41°F) for more than 2 hours:

  • raw or cooked meat, poultry, or seafood
  • milk/cream, yogurt, soft cheese
  • cooked pasta, pasta salads
  • custard, chiffon, or cheese pies
  • fresh eggs, egg substitutes
  • meat or cheese-topped pizza, luncheon meats
  • casseroles, stew, or soups
  • mayonnaise, tartar sauce, and creamy dressings
  • refrigerated cookie doughs
  • cream-filled pastries


Cook Foods to Minimum Temperatures to Ensure Food Safety

Use a cooking thermometer to be sure that the following foods are cooked to the minimum internal cooking temperature:



Ground Meats




Poultry and stuffed





Contacts for Further Information

Banner microbe: Borrelia burgdorferi, the bacterium causing Lyme disease,
from the American Museum of Natural History Epidemic! exhibition

Epidemic! | Exhibits