iPrep
ES Download
Study guide

Temperature Danger Zone: 41°F to 135°F, Cooling and Reheating Rules

Last checked:

The temperature danger zone is 41°F to 135°F. Bacteria grow in this range, and fastest between about 70°F and 125°F. Keep cold food at 41°F or below and hot food at 135°F or above, and move food through the zone quickly when you cool or reheat it.

RuleLimit
Cold holding41°F or below
Hot holding135°F or above
Cooling, stage 1135°F to 70°F within 2 hours
Cooling, total135°F to 41°F within 6 hours
Reheating for hot holding165°F for 15 seconds, within 2 hours
Untreated shell eggs (air temperature)45°F or below

What to know for the exam

  • Cooling has two stages. If food is still above 70°F after 2 hours, reheat it to 165°F and start again, or throw it out.
  • Food reheated for hot holding must reach 165°F in every part, whatever temperature it was first cooked to.
  • Food prepared for one customer to eat right away can be served at any temperature.
  • Check the air temperature in the warmest part of a cooler and the coolest part of a hot holding unit.
  • Time can replace temperature control for up to 4 hours if you have written procedures. After that, cook and serve, serve, or discard.

Quick quiz: temperature danger zone

  1. Question 1 of 5 · Holding and serviceA pot of chili is removed from the stove at 135°F at 2:00 PM. At 4:00 PM it measures 80°F. What should the manager do?
    Show answer and explanation

    Reheat the chili to 165°F and begin the cooling process again

    The food failed the first cooling stage: it had to reach 70°F within 2 hours and it is at 80°F. Because it has been cooked and is still above 70°F, it can be reheated to 165°F and cooled again using a faster method. Discarding is required when the food has spent too long in the danger zone overall, not for a first-stage miss that can be corrected immediately.

    Source: FDA Food Code, § 3-501.14(A)

  2. Question 2 of 5 · Holding and serviceHot and cold holding temperature requirements apply at all times except during
    Show answer and explanation

    preparation, cooking, or cooling.

    The holding requirements apply except during preparation, cooking, or cooling, or when time is being used as the public health control. Food inevitably passes through the danger zone while being prepped or cooled, and those transitions have their own time limits. Busy service periods and transport are not exceptions.

    Source: FDA Food Code, § 3-501.16(A)

  3. Question 3 of 5 · Holding and serviceYou are reheating yesterday's chili to put on the hot line. It must reach
    Show answer and explanation

    165°F.

    Food cooked, cooled and then reheated for hot holding must reach 165°F in all parts, no matter what it was originally cooked to. Do it quickly, on a range or in an oven rather than on the steam table, because the food may not spend more than 2 hours between 41°F and 165°F.

    Source: FDA Food Code, § 3-403.11(A)

  4. Question 4 of 5 · Holding and serviceSoup on a steam table reads 128°F two hours into service. The manager should
    Show answer and explanation

    reheat it to 165°F within 2 hours and correct the steam table.

    Hot holding requires 135°F or above, and food that has fallen below it needs a lethality step rather than simply more heat. Reheating for hot holding requires all parts to reach 165°F for 15 seconds, done rapidly with no more than 2 hours between 41°F and that temperature. The equipment fault also has to be fixed or the same thing happens next service.

    Source: FDA Food Code, § 3-403.11(A)

  5. Question 5 of 5 · Holding and serviceWithin the danger zone, pathogens multiply fastest between roughly
    Show answer and explanation

    70°F and 125°F.

    The zone of fastest growth is roughly 70°F to 125°F, which is why the first cooling stage is the tight one: food must clear 135°F down to 70°F within 2 hours, crossing the worst range quickly, and then has the remainder of the 6 hours for the slower stretch down to 41°F. Understanding this explains why the two stages have different allowances rather than one flat limit.

    Source: FDA Food Code, § 3-501.14(A)

Take the 40 question practice test

Questions and answers

What is the temperature danger zone?

The range from 41°F to 135°F, where bacteria that cause foodborne illness grow. Keep food out of it except while you prepare, cook or cool it.

How long can food stay in the danger zone?

Cooked food must cool from 135°F to 70°F within 2 hours and to 41°F within 6 hours in total. Under written time-as-control procedures, food can be out of temperature control for up to 4 hours.

What temperature do you reheat food to for hot holding?

165°F for 15 seconds, reached within 2 hours.

Other topics

Ready for the full practice?

500+ exam-style questions, a timed 90 question exam simulator and a study plan built around your exam date.

Download on the App Store

Free to download. Start with a free 20 question diagnostic. For iPhone, iPad and iPhone Duo.