Q.01

What are TCS foods?

"TCS food" stands for time/temperature control for safety food, a term from the FDA Food Code, the US model code for retail food. The Food Code defines it as food that "requires time/temperature control for safety (TCS) to limit pathogenic microorganism growth or toxin formation", and notes it was formerly called "potentially hazardous food" (PHF) [1].

Approach: I read the FDA Food Code 2026: the definitions in § 1-201.10 and the Chapter 3 rules for TCS food. The Food Code is a model code, so what actually applies in a given US state or locality depends on which edition that jurisdiction has adopted.

What counts as TCS food (§ 1-201.10) [1]

  • Animal food that is raw or heat-treated.
  • Plant food that is heat-treated, or is raw seed sprouts, cut melons, cut leafy greens, cut tomatoes or mixtures of cut tomatoes. This only applies if the food has not been changed so that it can no longer support pathogen growth or toxin formation.
  • Garlic-in-oil mixtures, under the same condition.
  • Any food marked "Product Assessment Required" (PA) in Table A or B of the definition, based on how its pH and water activity (aw) interact. Table A covers food that is heat-treated and then packaged. Table B covers food that is not heat-treated, or is heat-treated but not packaged. For example, in Table A a food with aw above 0.92-0.95 and pH above 5.6 is "PA".

What does not count as TCS food

  • Air-cooled hard-boiled eggs with the shell intact, and shell eggs pasteurized to destroy all viable Salmonellae.
  • Food in an unopened hermetically sealed container that is commercially processed to stay commercially sterile without refrigeration.
  • Food that Table A or B classes as non-TCS because of its pH, its aw or the combination of the two. For example, in Table A any food with aw of 0.92 or less is non-TCS.
  • Food marked "PA" whose product assessment shows that pathogen growth or toxin formation is prevented by:
    • intrinsic factors, such as preservatives, humectants or acidulants;
    • extrinsic factors, such as packaging, reduced oxygen packaging, shelf life or storage temperature;
    • or both.

Main Food Code controls on TCS food

  • Hot and cold holding (§ 3-501.16): TCS food "shall be maintained" at 57°C (135°F) or above, or at 5°C (41°F) or less. Some roasts may be held at 54°C (130°F) or above. These limits do not apply during preparation, cooking or cooling, or when time is used as the control [2].
  • Date marking (§ 3-501.17): refrigerated, ready-to-eat TCS food held for more than 24 hours "shall be clearly marked" with the date by which it must be eaten, sold or discarded. That is a maximum of seven days at 5°C (41°F) or less, with the day of preparation (or the day a commercial container is opened) counted as Day 1 [3].
  • Time as a public health control (§ 3-501.19): TCS food can be held without temperature control for up to four hours, or up to six hours under stricter conditions. This requires written procedures, a time mark on the food, and discarding the food once the limit is reached [4].
Q.02

Which temperatures keep TCS foods safe?

Under the FDA Food Code 2026, TCS food is safe when it is held cold at 5°C (41°F) or less or hot at 57°C (135°F) or above. Cooked roasts can be hot-held at 54°C (130°F) or above [2]. Cooking, reheating, cooling and thawing each have their own temperature and time limits, listed below.

Approach: I read the Chapter 3 temperature provisions of the FDA Food Code 2026, which is a model code. The rules that actually apply in a US state or locality depend on which edition it has adopted.

Holding (§ 3-501.16) [2]

  • TCS food "shall be maintained" at 57°C (135°F) or above, or at 5°C (41°F) or less.
  • Roasts cooked under ¶ 3-401.11(B), or reheated under ¶ 3-403.11(E), may be held at 54°C (130°F) or above.
  • These limits do not apply during preparation, cooking or cooling, or when time is used as the public health control (§ 3-501.19).
  • Shell eggs not treated to destroy Salmonellae must be stored in equipment with an ambient air temperature of 7°C (45°F) or less.

Cooking raw animal food (§ 3-401.11) [5] All parts of the food must reach these temperatures for these times:

FoodMinimum temperature and time
Eggs broken for immediate service; fish; intact meat63°C (145°F) for 15 seconds
Comminuted (ground) fish and game; non-intact meat; ratites; other raw eggs68°C (155°F) for 17 seconds, or 63°C (145°F) for 3 minutes, 66°C (150°F) for 1 minute, or 70°C (158°F) for under 1 second
Poultry; baluts; wild game; stuffed fish, meat, pasta or poultry; stuffing containing fish, meat or poultry74°C (165°F) for under 1 second
Whole meat roastsTime-temperature chart, for example 54.4°C (130°F) for 112 minutes, 62.8°C (145°F) for 4 minutes, 70°C (158°F) for 0 minutes

Reheating for hot holding (§ 3-403.11)

  • Cooked and cooled TCS food: all parts must reach at least 74°C (165°F) for 15 seconds [6].
  • Microwave reheating: all parts must reach 74°C (165°F). The food is then rotated or stirred, covered, and left to stand covered for 2 minutes [6].
  • Commercially processed, packaged ready-to-eat TCS food: must be heated to at least 57°C (135°F) [6].
  • Speed: reheating must be done rapidly. The time the food spends between 5°C (41°F) and these target temperatures "may not exceed two hours" [7].

Cooling (§ 3-501.14)

  • Cooked TCS food: from 57°C (135°F) to 21°C (70°F) within 2 hours, and to 5°C (41°F) or less within 6 hours in total [8][9].
  • Food made from ingredients at room temperature (for example reconstituted foods or canned tuna): to 5°C (41°F) or less within 4 hours [9].
  • Food legally received above 5°C (41°F): to 5°C (41°F) or less within 4 hours [9].

Frozen food, slacking and thawing (§§ 3-501.11 to 3-501.13)

  • Frozen storage: stored frozen foods "shall be maintained frozen" [7].
  • Slacking: slacked TCS food is held under refrigeration at 5°C (41°F) or less [7].
  • Thawing is allowed in any of these ways [10]:
    • under refrigeration, keeping the food at 5°C (41°F) or less;
    • fully submerged under running water at 21°C (70°F) or below, without ready-to-eat portions rising above 5°C (41°F);
    • as part of cooking.
Q.03

How should restaurants cool and reheat them?

Under the FDA Food Code 2026, restaurants should cool cooked TCS food from 57°C (135°F) to 21°C (70°F) within 2 hours, and to 5°C (41°F) or less within 6 hours in total. Food reheated for hot holding should reach at least 74°C (165°F) for 15 seconds in all parts, and reheating must be rapid (no more than 2 hours from 5°C (41°F) to the target) [8][9][6][7]. The Code also says which cooling methods to use and how to load food into the cooler.

Approach: I read §§ 3-403.10, 3-403.11, 3-501.14, 3-501.15 and 3-501.16 of the FDA Food Code 2026. It is a model code, so what is enforceable depends on the edition your state or locality has adopted.

Cooling

Time and temperature limits (§ 3-501.14)

  • Cooked TCS food "shall be cooled" from 57°C to 21°C (135°F to 70°F) within 2 hours. It must reach 5°C (41°F) or less within 6 hours in total [8][9].
  • Food made from ingredients at room temperature (for example reconstituted foods or canned tuna): 5°C (41°F) or less within 4 hours [9].
  • Food lawfully received above 5°C (41°F): 5°C (41°F) or less within 4 hours. Raw eggs go straight into refrigerated equipment with an ambient air temperature of 7°C (45°F) or less [9].

Methods (§ 3-501.15(A)) [9] Use one or more of these methods, chosen to suit the food:

  • shallow pans;
  • smaller or thinner portions;
  • rapid cooling equipment;
  • stirring the food in a container set in an ice water bath;
  • containers that help heat transfer;
  • adding ice as an ingredient;
  • food no more than 2 inches deep;
  • other effective methods.

Loading the cooler (§ 3-501.15(B)) [9] Containers of cooling food "shall be":

  • arranged in the equipment so heat transfers through the container walls as fully as possible;
  • loosely covered while cooling. They can be left uncovered if protected from overhead contamination.

Approved alternative (§ 3-501.15(C)) A food establishment "may" cool cooked TCS food this way if it is approved. The food must be:

  • filled no more than 2 inches deep;
  • held uncovered;
  • in a refrigeration unit that keeps an ambient temperature of 5°C (41°F) or less and has an electronic system that continuously monitors time and ambient air temperature.

This option excludes food cooled under ¶ 3-401.14(B), Subparagraph 3-502.12(D)(2)(e) or § 3-501.19 [9][2].

Reheating

Reheating for hot holding (§ 3-403.11) [6]

FoodRequirement
TCS food that was cooked, cooled and is now reheatedAll parts reach at least 74°C (165°F) for 15 seconds
Microwave reheatingAll parts reach at least 74°C (165°F). Then rotate or stir, cover, and let stand covered for 2 minutes
Commercially processed, packaged ready-to-eat TCS food (from an inspected plant)Heated to at least 57°C (135°F)
Remaining unsliced portions of meat roasts cooked under ¶ 3-401.11(B)May be reheated using the oven settings and minimum time and temperature in ¶ 3-401.11(B) [7]
  • Speed (¶ (D)): reheating "shall be done rapidly". The time between 5°C (41°F) and the target temperature "may not exceed two hours" [6][7].
  • Single orders (§ 3-403.10): cooked and refrigerated food prepared for immediate service to one customer's order "may be served at any temperature" (the Code's example is a roast beef sandwich au jus) [6].
  • After reheating (§ 3-501.16): hold at 57°C (135°F) or above. Roasts reheated under ¶ 3-403.11(E) may be held at 54°C (130°F) or above [2].
Q.04