As bitter cold weather sweeps across the nation, and with Oklahoma expecting its first big winter storm, food safety often takes a backseat to staying warm. However, USDA experts warn that losing electricity can quickly turn a refrigerator from a preservation tool into a safety hazard.
In a recent conversation, Rod Bain of the USDA and Meredith Carothers of the Food Safety and Inspection Service discussed the critical “rules of thumb” every household should know when the lights go out.
The 40-Degree “Danger Zone”
The cornerstone of food safety is temperature control. According to Carothers, the magic number is 40 degrees Fahrenheit.
“Food needs to be below 40 degrees Fahrenheit in the refrigerator to be considered safe,” Carothers explains. “So once that temperature starts creeping above 40 degrees Fahrenheit, you’ve reached the danger zone and it’s going to only have a certain amount of time before it’s unsafe.”
The Refrigerator Clock: You Have 4 Hours
When power is lost, a refrigerator essentially becomes a giant insulated cooler. However, it cannot hold its temperature indefinitely. Carothers advises that a refrigerator with no power will keep a safe temperature for about four hours, provided the door remains closed.
As the four-hour deadline approaches, households should make a critical decision.
- Action Plan: If you have access to a cooler and ice, transfer food before the four-hour mark to keep it safe until power returns.
- The Deadline: If a cooler isn’t available, after four hours, specific perishable foods must be discarded.
What to Keep and What to Toss
Not all food reacts to warming temperatures in the same way. Carothers outlines specific categories of food that are vulnerable to bacteria growth and must be thrown away after four hours without power:
- Meat & Poultry: Raw meats and poultry are high-risk.
- Leftovers: Any cooked leftovers.
- Dairy: Milk, soft cheeses, and eggs.
- Produce: Cut fruits and vegetables, and cooked vegetables.
Conversely, some items have more resilience. Whole fruits (uncut), hard cheeses, and certain condiments (like jelly, mustard, and ketchup) can generally be kept safely for longer periods.
The Freezer Advantage
Freezers offer significantly more protection than refrigerators due to the thermal mass of the frozen food itself.
“A refrigerator that has no power is going to keep a safe temperature for about 4 hours,” notes Bain.
In contrast, a freezer can hold safe temperatures for:
- 48 Hours: If the freezer is full.
- 24 Hours: If the freezer is half-full.
The logic is simple: the more frozen food you have, the more “cold source” exists inside the appliance to maintain the temperature.
The “Nature’s Refrigerator” Myth
Facing freezing outdoor temperatures, many people attempt to salvage their food by storing it outside in the snow or on a porch. The USDA strongly discourages this.
Carothers warns that outdoor conditions are unpredictable. “The sun can come out and warm things up even if the air is cold,” leading to temperature fluctuations that encourage bacterial growth. Furthermore, storing food outside exposes it to contamination from animals and bacteria.
Summary of Safety Times
| Appliance | Condition | Safe Time Estimate |
| Refrigerator | Door Closed | ~ 4 Hours |
| Freezer | Half-Full | ~ 24 Hours |
| Freezer | Full | ~ 48 Hours |
