When the power goes out, every minute counts for the safety of the food in your refrigerator and freezer. Without electricity, perishable items can quickly enter the temperature danger zone (above 40°F or 4°C), where bacteria multiply rapidly and increase the risk of foodborne illness. Knowing exactly what to do before, during, and after an outage can save you money and protect your customers or family.
How long can a full freezer keep food safe during a power outage if the door remains closed?
Select one answer.
How long does food stay safe?
Your refrigerator will keep food safe for up to 4 hours during a power outage if you keep the door closed, according to the FDA and FoodSafety.gov. After that, perishable items like meat, poultry, fish, eggs, milk, cut fruit, and leftovers should be discarded if they have been above 40°F for two hours or more FoodSafety.gov.
A full freezer can maintain a safe temperature for about 48 hours (24 hours if half-full) as long as the door stays shut. Food that still contains ice crystals or has been kept at 40°F or below can be safely refrozen or cooked USDA Food Safety and Inspection Service.
Before the outage: prepare your kitchen
- Keep an appliance thermometer in both the refrigerator and freezer. The fridge should be at or below 40°F, and the freezer at 0°F or below.
- Group food items together in the fridge and freezer so they help keep each other cold.
- Freeze containers of water or gel packs ahead of time to use as cold sources during an outage.
- Have a supply of nonperishable food and bottled water on hand for at least three days.
During the outage: keep the cold in
- Keep refrigerator and freezer doors closed. Opening the door lets cold air escape and shortens the safe storage window.
- If the outage is expected to last more than 4 hours, add block ice or dry ice to the refrigerator. Use 3 pounds of dry ice per cubic foot of freezer space, and handle dry ice with gloves or tongs Clemson Cooperative Extension.
- Never taste food to check if it's still safe. When in doubt, throw it out.
After the power returns: what to keep and what to toss
Use this checklist to decide:
- Keep if the refrigerator stayed below 40°F and the power was out less than 4 hours.
- Keep frozen food that still has ice crystals or feels refrigerator-cold (40°F or below).
- Discard any perishable food that has been above 40°F for 2 hours or more.
- Discard any food with an unusual odor, color, or texture.
- Discard items like milk, soft cheeses, eggs, fresh meat, poultry, fish, cut fruit, and leftovers if the power was out more than 4 hours.
- Cook leftovers to an internal temperature of at least 165°F before eating University of Connecticut Food Safety.
Quiz: test your knowledge
How long can a full freezer keep food safe during a power outage if the door remains closed?
- 24 hours
- 48 hours
- 4 hours
How the Resident Expert Can Help
Utah State Food Handlers offers live, in-person food safety certification classes across Utah. Their hands-on training covers essential topics like time and temperature control, cross-contamination prevention, and emergency preparedness. Visit Home | Utah State Food Handlers to find a class near you and get your permit fast.