Power-outage food safety
Is Mayonnaise Safe After a Power Outage?
The short answer
Discard opened mayonnaise if it was above 50°F for more than 8 hours.
Official decision table
| Food or condition | Action or period | When it applies |
|---|---|---|
| Opened mayonnaise at 50°F or below | Keep | Return to refrigeration |
| Above 50°F for more than 8 hours | Discard | Also applies to tartar sauce and horseradish |
How to make the decision
Never taste food to decide whether it is safe after an outage. Time, measured temperature, ice crystals, and the official item chart control the decision.
When a package provides stricter storage or discard instructions, use the package. People at higher risk from foodborne illness should be especially conservative with refrigerated perishables.
What to do now
- Record how long the refrigerator, freezer, or package was outside its intended temperature range.
- Use a food or appliance thermometer when a temperature reading is available.
- Apply the exact row above instead of relying on smell, appearance, or a taste test.
- When the time or temperature is unknown, choose the safer action.
Check the underlying storage record
Use the complete FoodKeeper database for normal pantry, refrigerator, freezer, after-opening, and after-thawing periods.
Primary source
FoodSafety.gov Food Safety During a Power Outage. ShelfDate has reorganized the applicable rows for readability without replacing the official decision criteria.