ShelfLife
The 2-hour rule: how long can food sit out?
Perishable food shouldn't stay at room temperature for more than 2 hours in total, or 1 hour when it's above 32 °C (90 °F). After that, throw it out, even if it looks and smells fine.
Updated November 4, 2026
The danger zone
Bacteria grow fastest between 4 °C and 60 °C (40 °F and 140 °F), the range the USDA calls the "danger zone". In that range, their numbers can double in as little as 20 minutes. That's why the rule is:
- Keep cold food cold: at 4 °C (40 °F) or below.
- Keep hot food hot: at 60 °C (140 °F) or above.
- Don't leave perishable food in between for more than 2 hours, or 1 hour above 32 °C (90 °F), for example at a summer picnic or in a hot car.
The 2 hours are cumulative: time in the shopping cart, the car, on the counter and on the table all count.
What counts as perishable
The rule applies to food that needs to be refrigerated:
- Meat, poultry, fish and seafood, raw or cooked
- Eggs and egg dishes
- Milk, cream, yogurt, soft cheese
- Cooked rice, pasta and vegetables
- Leftovers, soups, pizza, potato salad and other prepared dishes
- Cut fruit and vegetables
Foods normally kept at room temperature, like bread, whole fruit and dry snacks, aren't covered by the 2-hour rule.
Why reheating doesn't fix it
Some bacteria, like Staphylococcus aureus and Bacillus cereus (the one behind fried-rice food poisoning), produce toxins as they grow. Cooking kills the bacteria but doesn't destroy those toxins. Food left out too long stays unsafe even if you bring it back to a boil.
How to cool food quickly
- Don't wait for food to cool on the counter. Put it in the fridge within 2 hours; fridges are designed for warm food.
- Divide large amounts into shallow containers so the center cools fast. A big pot of soup or chili can stay warm for hours.
- Cut large roasts into smaller pieces.
- For soup, set the pot in a sink of ice water and stir before dividing it.
Picnics, parties and shopping
- Keep cold food in a cooler with ice packs, and the cooler in the shade.
- Put serving dishes on ice, or set out small portions and replace them from the fridge.
- Make perishable food the last thing in your cart, and use an insulated bag on hot days.
When the power goes out
According to USDA and CDC guidance, a closed fridge keeps food cold for about 4 hours, a full freezer for about 48 hours, and a half-full freezer for about 24 hours. Keep the doors closed. After 4 hours without power, throw out perishable fridge food like meat, dairy, eggs and leftovers.
When in doubt, throw it out.
Sources
- USDA Food Safety and Inspection Service: USDA urges consumers to keep clear of the danger zone
- USDA FSIS: Food product dating
Add leftovers to ShelfLife when you put them away, and get a reminder before they're too old.