The food danger zone is the range between the cold limit and the hot limit where bacteria grow fastest, and the FDA's figures bound it. The FDA's safe food handling page, cited below, says to keep the refrigerator at 40°F or below and the freezer at 0°F or below, to refrigerate perishables within 2 hours of cooking or purchasing and within 1 hour if the temperature outside is above 90°F, and its buffet guidance keeps hot foods at 140°F or warmer and cold foods at 40°F or colder. Between those two figures, time is the hazard, and the two-hour rule is the limit on it. The danger zone temperature log planner on this site sizes the record a kitchen keeps of its cold storage and hot holding, free and without an account; the paid product keeps the readings.
The cold side
The refrigerator at 40°F or below and the freezer at 0°F or below, checked and recorded on the plan's schedule. Cold food on a buffet kept at 40°F or colder. A reading above the limit is a corrective action, not a note.
The hot side
Hot food held at 140°F or warmer, on the buffet and the line, checked with a probe and recorded. The FDA's safe cooking temperatures, from the same page: 145°F with a 3 minute rest for whole cuts of beef, pork, veal and lamb and for fin fish; 160°F for ground meat and egg dishes; 165°F for poultry, leftovers and casseroles; 140°F to reheat fully cooked ham. Cooking gets food out of the zone; holding keeps it out; the log shows both.
The time in between
Perishables refrigerated within 2 hours of cooking or purchasing, within 1 hour if it is above 90°F outside. Cooling is the step where food passes back through the zone, and the plan's cooling limit and record are where a kitchen most often has a gap.
The log
Fridges, freezers, hot holding and cooling, each with its limit and its checks per day. The planner on this site prints the log sized to the kitchen; ProbeLedger Pro keeps the readings and the corrective actions against each unit. FoodDocs lists its Lite plan at $99 per site per month billed monthly or $79 billed annually, and its Standard plan at $199 per site per month, with a free 14-day trial, on its pricing page cited below. ProbeLedger Pro is $49 per month for the whole site.
Questions people ask about food danger zone
Is the danger zone the same in the UK?
The FSA gives its own figures in Celsius; the UK pages on this site cite them.
Does the two-hour rule apply to cooked food at room temperature?
Yes; the FDA's figure is for perishables after cooking or purchase.
Is the log planner free?
Yes, without an account.