Safe Food Handling and Time-Temperature Control
What you must know
The temperature danger zone is 41°F–135°F. Time as a public health control allows food to be held without temperature control for a defined period (commonly 4 hours, then discard). Cold TCS food is held at 41°F or below; hot TCS food at 135°F or above.
Cooking minimums (memorize): poultry and stuffed foods 165°F; ground meat 155°F for 17 seconds; whole-muscle pork/beef and fish 145°F for 15 seconds; vegetables for hot holding 135°F. Cooling must go from 135°F to 70°F within 2 hours and to 41°F within a total of 6 hours. Reheating for hot holding is to 165°F for 15 seconds within 2 hours.
Traps
Questions mix up cooling stages (2 hours to 70°F, then 4 more hours to 41°F-total 6). Another trap: ground poultry is treated like poultry (165°F), not like ground beef (155°F). Also, thawing under running water must be at 70°F or below, and thawing as part of cooking is allowed. Thermometers must be calibrated (ice-point method: 32°F).
Rule of thumb
165 → 155 → 145 → 135: poultry/stuffed, ground, whole muscle, hot-hold vegetables. When a stem gives a temperature and asks "is it safe," compare it directly to these thresholds and the 2/4/6-hour cooling clock.