Topic 3 of 8 · about 17% (our estimate)
Time and temperature: the numbers a kitchen runs on
Time and temperature is the topic with the most numbers in it, and a food safety thermometer is how you prove each one. TCS food, short for time/temperature control for safety, has to stay out of the danger zone, 41–135°F (5–57°C), or pass through it quickly.
- ExamPFH
- Topic weight17%
- Questions here15
- UpdatedOct 14, 2026
On this page 8 sections
Why the band matters
Between 41°F and 135°F, bacteria in TCS food multiply quickly. Below the band growth slows to a crawl, above it growth stalls, and inside it the count climbs every hour the food sits. The band has its own page: the temperature danger zone.
TCS food is food that lets bacteria grow: raw or cooked meat, poultry and seafood; cooked rice, beans and potatoes; raw sprouts, cut leafy greens and cut tomatoes. You may still see the older name, potentially hazardous food (PHF), on labels and in older quizzes.
A kitchen's numbers on one thermometer
Cook, hold, cool, reheat
| Step | The rule | Food Code 2022 |
|---|---|---|
| Cook poultry | 165°F, instantly (under 1 second) | 3-401.11(A)(3) |
| Cook ground meat | 155°F for 17 seconds | 3-401.11(A)(2) |
| Cook steaks, chops, fish | 145°F for 15 seconds | 3-401.11(A)(1) |
| Hold hot | 135°F or above | 3-501.16(A)(1) |
| Hold cold | 41°F or below | 3-501.16(A)(2) |
| Cool cooked food | 135°F to 70°F within 2 hours, then to 41°F within 6 hours total | 3-501.14(A) |
| Reheat for hot holding | 165°F for 15 seconds, reached within 2 hours | 3-403.11 |
| Time as a public health control | Written procedure, marked discard time | 3-501.19 |
Food-by-food detail: minimum internal cooking temperatures.
The thermometer, used like it counts
A thermometer that measures food has to be accurate to within ±2°F, or ±1°C on a Celsius scale (FDA Food Code 2022, 4-203.11). A glass of crushed ice topped with water should read 32°F; if yours reads 36°F, every number it gives you during the shift is 4 degrees off.
Probe more than one piece in a batch. The thin end of a sheet tray cooks first and the middle of a stockpot cools last, and the reading you write down should come from the slowest piece.
Is the soup hot enough to hold? Steam rising off the pot only says it's warm. A probe reading of 135°F or above says it's safe to hold, and a food handler test will only accept the number.
Run the numbers
Some of these are about why bacteria grow at all; the rest put a number to work. When you've got this topic down, take the numbers into the mixed food handler practice test.
Each question is a chit, an order ticket. Answer it and it flips to show why every option is right or wrong.
No. 01
A cook is microwaving a raw chicken breast for an order. What does the Food Code call for?
Pick one. The chit flips to a note on every option.
Notes on No. 01
- A
Heat it to 135°F and serve it right away 135°F is the hot-holding number and the cooking temperature for fruits and vegetables, not for raw chicken.
- B
Heat it to 165°F, then let it stand 2 minutes Correct: Microwaves heat unevenly, so raw animal food must hit 165°F everywhere, covered and stirred or rotated, then stand 2 minutes so the heat evens out.
- C
Heat it until the outside turns white Color lies: microwaved chicken can look white outside while cold spots inside stay raw; only a thermometer tells you.
- D
Heat it to 145°F, then rest it 3 minutes 145°F works for steaks and fish cooked the usual way, but raw animal food cooked in a microwave needs 165°F.
- A
No. 02
Which condition is necessary for bacteria to grow?
Pick one. The chit flips to a note on every option.
Notes on No. 02
- A
Freezing temperatures Freezing stops bacteria from multiplying, though it doesn't kill most of them.
- B
High salt content High salt pulls water away from bacteria, which is why cured and salted foods keep longer.
- C
Moisture Correct: Bacteria need available water to grow, so moist foods like cooked rice, meat, and cut melon are the ones that need time and temperature control.
- D
Bright light Light plays no role in bacterial growth; most bacteria do fine in a dark walk-in.
- A
No. 03
Which condition does NOT support bacterial growth?
Pick one. The chit flips to a note on every option.
Notes on No. 03
- A
High acidity Correct: Bacteria grow best in foods close to neutral pH, so acidic foods like pickles and vinegar dressings hold them back.
- B
Warm temperature Warmth between 41°F and 135°F is exactly where bacteria multiply fastest.
- C
Moisture Moisture feeds bacteria; it is one of the conditions they need, not one that stops them.
- D
Protein-rich food Protein-rich foods like meat, eggs, and dairy are the ones bacteria like best.
- A
No. 04
What type of bacteria can grow without oxygen?
Pick one. The chit flips to a note on every option.
Notes on No. 04
- A
Aerobic bacteria Aerobic bacteria need oxygen to grow, the opposite of what the question asks.
- B
Protozoa Protozoa are single-celled parasites, not bacteria, and they don't multiply in food.
- C
Fungi Fungi such as molds and yeasts are not bacteria, and molds need air to grow.
- D
Anaerobic bacteria Correct: Anaerobic bacteria like Clostridium botulinum grow without oxygen, which is the risk in vacuum packs, garlic-in-oil, and the center of big pots.
- A
No. 05
Which factor most influences bacterial growth rate?
Pick one. The chit flips to a note on every option.
Notes on No. 05
- A
Light exposure Light has little effect on how fast bacteria multiply in food.
- B
Air pressure Normal changes in air pressure don't affect bacterial growth.
- C
Temperature Correct: Temperature controls growth speed more than anything else; between 41°F and 135°F, bacteria can double in about 20 minutes.
- D
Container size Container size changes how fast food cools, but temperature itself is what drives growth.
- A
No. 06
A cook steams green beans that will go straight into the hot well. What minimum temperature must they be cooked to?
Pick one. The chit flips to a note on every option.
Notes on No. 06
- A
155°F (68°C) 155°F is for ground meat and for eggs held hot; vegetables don't need it.
- B
165°F (74°C) 165°F is for poultry and for reheating leftovers; it's safe for green beans but higher than the minimum.
- C
135°F (57°C) Correct: Fruits and vegetables cooked for hot holding must reach 135°F; the higher numbers are for meat, poultry, fish, and eggs.
- D
120°F (49°C) 120°F is inside the danger zone, so beans held at that temperature can grow bacteria.
- A
No. 07
When using a food thermometer, where should it be inserted to check temperature?
Pick one. The chit flips to a note on every option.
Notes on No. 07
- A
Any convenient spot A random spot may be the hottest part of the food and hide a cold center.
- B
Thickest part of the food Correct: The thickest part heats last, so that is where you check, keeping the probe away from bone and fat.
- C
Just below the surface The surface cooks first, so a shallow reading can show a safe number while the center is still raw.
- D
The edge of the food Edges heat fastest and give a falsely high reading.
- A
No. 08
What is the correct procedure for testing oil temperature in a deep fryer?
Pick one. The chit flips to a note on every option.
Notes on No. 08
- A
Use a calibrated thermometer in center of fryer Correct: Only a calibrated high-heat thermometer gives the real number, and reading it in the middle avoids hot spots near the heating element.
- B
Drop in a test piece and time how fast it browns Browning speed depends on the food and the batter, so it can't tell you the actual oil temperature.
- C
Check that the oil has turned a golden color Oil darkens with use, so its color tells you about its age, not its temperature.
- D
Watch for steady bubbles around the basket Bubbling comes from moisture in the food and looks about the same over a wide range of temperatures.
- A
No. 09
How should temperature measuring devices be stored?
Pick one. The chit flips to a note on every option.
Notes on No. 09
- A
Lying flat on the prep surface by the station A bare prep surface exposes the probe to splashes and raw juices between uses.
- B
In the chemical bin with cleaning supplies Storing it with chemicals can coat the probe with something that ends up in the next food.
- C
Clean and sanitized in designated container Correct: A thermometer is a food-contact tool, so it is kept clean and sanitized in its own holder where it won't pick up contamination or get damaged.
- D
In a shirt pocket so it is always handy Pockets collect lint and germs from hands and clothing, which then go straight into the food.
- A
No. 10
How should temperature probes be sanitized between uses?
Pick one. The chit flips to a note on every option.
Notes on No. 10
- A
Wipe with a dry cloth from the prep station A dry cloth may smear residue around and can carry germs from the last thing it touched.
- B
Clean and sanitize with alcohol wipes or sanitizer Correct: Cleaning removes food residue and sanitizing kills what's left, so raw-meat germs don't ride the probe into the next food.
- C
Use as-is; the heat of the next food cleans it Hot food doesn't sanitize a probe; the next item may not be hot enough, and ready-to-eat food gets no heat at all.
- D
Rinse with warm water and shake it dry Water alone rinses off loose bits but doesn't sanitize the probe.
- A
No. 11
A cook scrambles a big batch of raw shell eggs to hold hot on the breakfast buffet. What minimum internal temperature must the eggs reach?
Pick one. The chit flips to a note on every option.
Notes on No. 11
- A
145°F (63°C) 145°F is for eggs cracked and cooked to order for immediate service, not for a batch held hot.
- B
165°F (74°C) 165°F is the poultry and reheating number; it's safe for eggs but higher than the minimum.
- C
155°F (68°C) Correct: Eggs cooked for hot holding must reach 155°F for 17 seconds; 145°F is only for eggs cooked to order and served right away.
- D
135°F (57°C) 135°F is the temperature for holding food hot, not for cooking raw eggs.
- A
No. 12
What is the primary cause of bacterial multiplication in food?
Pick one. The chit flips to a note on every option.
Notes on No. 12
- A
Time and temperature abuse Correct: Bacteria multiply when food sits too long between 41°F and 135°F; contamination brings them in, but time and heat let them grow.
- B
Food handling Handling can add germs to food, but they multiply only when time and temperature allow it.
- C
Cross-contamination Cross-contamination moves germs from one place to another; it doesn't make them multiply.
- D
Poor sanitation Dirty surfaces spread bacteria, but growth inside the food depends on time and temperature.
- A
No. 13
What is the proper method for storing cut melons during service?
Pick one. The chit flips to a note on every option.
Notes on No. 13
- A
On a sheet pan under the heat lamp A heat lamp warms cut melon into the danger zone; cut melon is TCS food and is held at 41°F or below.
- B
Covered, dated, and held at 50°F or below 50°F is inside the danger zone; covering and dating cut melon don't make up for holding it too warm.
- C
Covered, dated, and held at 41°F or below Correct: Cut melon is a TCS food: hold it at 41°F or below, keep it covered, and date it, since it can be kept for up to 7 days.
- D
Uncovered in the cooler so they stay crisp Uncovered fruit in the cooler can pick up drips from the shelves above.
- A
No. 14
How should leftover hot food be stored?
Pick one. The chit flips to a note on every option.
Notes on No. 14
- A
Cooled properly, then in shallow covered pans Correct: Hot food first goes through two-stage cooling, 135°F to 70°F in 2 hours and down to 41°F within 6 hours total, then it is stored covered.
- B
Uncovered in the refrigerator Food may sit loosely covered while it cools, but once cold it is covered to keep drips and debris out.
- C
At room temperature overnight to cool down Overnight at room temperature leaves food in the danger zone for hours, so bacteria and toxins build up.
- D
In deep stockpots placed in the cooler while hot Deep pots cool too slowly in the center and often miss the 2-hour limit for the first stage.
- A
No. 15
A deli puts sandwiches out on a counter display using time instead of temperature control. What must the staff do?
Pick one. The chit flips to a note on every option.
Notes on No. 15
- A
Mark when 4 hours is up, then toss what's left Correct: Food held under time control is marked with the time 4 hours after it left temperature control, and anything left at that time is thrown out.
- B
Put them back in the cooler after 4 hours Food can't go back into the cooler at hour 4 to restart the clock; when the 4 hours are up, it is discarded.
- C
Check them with a thermometer every hour Under time as a control, the clock is the safeguard, not the thermometer; what's required is marking the discard time.
- D
Label them only with the day they were made The prep day doesn't tell anyone when the 4 hours run out; the label must show the discard time.
- A
Nothing matches both filters. Clear one of them.
Quick checks on temperature
What temperature range is the danger zone?
41°F to 135°F (5°C to 57°C). The Food Code doesn't use the phrase; the band is the gap between the cold-holding and hot-holding limits in section 3-501.16 of the 2022 edition.
How accurate does a food thermometer have to be?
Within ±2°F for a Fahrenheit thermometer, or ±1°C for a Celsius one (FDA Food Code 2022, 4-203.11).
Did the 2026 Food Code change any of these temperatures?
No. The FDA released the 2026 edition on September 17, 2026, and the cooking, holding, cooling and reheating numbers stayed the same (FDA summary of changes, as of October 2026). NEHA builds the PFH course on the 2022 edition (NEHA, as of October 2026).
Sources
- FDA Food Code 2022 — 3-401.11, 3-403.11, 3-501.14, 3-501.16, 3-501.19, 4-203.11 checked Oct 13, 2026
- FDA, summary of changes in the 2026 Food Code — released September 2026; cooking, holding, cooling and reheating numbers kept checked Oct 13, 2026
- NEHA, Professional Food Handler Certificate — course built on the 2022 FDA Food Code checked Oct 13, 2026