The temperature danger zone is 41°F to 135°F (5°C to 57°C), the range where bacteria on time/temperature control for safety (TCS) foods multiply fastest. Under the FDA Food Code, TCS food should not sit in this zone for more than 4 hours total before it must be discarded.
The temperature danger zone is the range in which disease-causing bacteria such as Salmonella, E. coli and Listeria grow most rapidly. Under the FDA Food Code 2022, that range is 41°F to 135°F (5°C to 57°C) for retail and food service establishments. Foods that support this growth are called TCS foods (Time/Temperature Control for Safety), formerly known as "potentially hazardous foods" — meats, poultry, seafood, dairy, cooked rice and pasta, cut leafy greens, cut tomatoes, cut melons, and garlic-in-oil mixtures are common examples.
A note on numbers: the USDA (FSIS) tells home cooks the danger zone is 40°F to 140°F. This is not a contradiction — USDA uses rounded, conservative figures for consumers, while the FDA Food Code sets the enforceable 41°F/135°F thresholds that health inspectors apply in commercial kitchens. If you operate a food business, follow the Food Code numbers (or your state's adopted version).
FDA Food Code §3-501.16 sets the holding rules that keep food out of the danger zone:
Holding equipment is not cooking equipment. A steam table or hot-holding cabinet is designed to maintain 135°F, not to bring cold food up through the danger zone. Always heat food to its required cooking temperature first, then transfer it to hot holding.
Bacteria need time as well as temperature. The practical guidance most operators know as the 2-hour rule comes from USDA: perishable food left in the danger zone should be refrigerated within 2 hours (or within 1 hour if the ambient temperature is above 90°F/32°C).
The Food Code's formal mechanism is Time as a Public Health Control (TPHC) under §3-501.19. With written procedures, an establishment may hold TCS food without temperature control for a limited window:
Food held under time control must be marked with the discard time and thrown out when the window closes.
Cooking to the correct internal temperature is the single most reliable kill step for pathogens. Verify with a calibrated probe thermometer at the thickest part. Key minimums from §3-401.11:
| Food | Minimum internal temp | Time |
|---|---|---|
| Poultry, stuffed meats/pasta/poultry, stuffing, wild game | 165°F (74°C) | Instantaneous (<1 sec) |
| Ground/comminuted meat, injected meats, ratites, eggs held for service | 155°F (68°C) | 17 seconds |
| Fish, whole-muscle beef/pork, eggs cooked for immediate service | 145°F (63°C) | 15 seconds |
| Whole beef/pork roasts | 145°F (63°C) | 4 minutes (per time-temp table) |
| Plant foods for hot holding, commercially processed ready-to-eat | 135°F (57°C) | — |
Cooling is where many kitchens fail, because food passes slowly back through the danger zone. FDA Food Code §3-501.14 requires a two-stage cooling process:
If Stage 1 (the most dangerous phase) is not met within 2 hours, the food may be reheated and cooled again once, or discarded. Food prepared from ingredients at room temperature must be cooled to 41°F within 4 hours. Speed cooling with shallow pans, ice-water baths, ice paddles, or a blast chiller.
When reheating TCS food for hot holding, §3-403.11 requires reaching 165°F (74°C) for 15 seconds within 2 hours. Commercially processed, ready-to-eat food reheated for immediate service only needs to reach 135°F.