TL;DR
Thawing frozen time/temperature control for safety (TCS) food is governed by FDA Food Code §3-501.13, which recognizes FOUR approved methods and rules out the dangerous ones — above all, thawing at room temperature on a counter. The four methods are: (1) UNDER REFRIGERATION, keeping the food at 41°F (5°C) or below throughout; (2) COMPLETELY SUBMERGED UNDER RUNNING WATER at 70°F (21°C) or below, with enough water velocity to agitate and float off loose particles, and only for a limited time; (3) AS PART OF THE COOKING PROCESS, where the frozen food goes straight into cooking that brings it to its required temperature without a separate thaw step; and (4) IN A MICROWAVE, but only if the food is then cooked immediately with no interruption. The unifying principle is that thawing must not let any part of the food linger in the temperature danger zone, because the outside of a thawing item warms into that zone long before the frozen center catches up. Refrigeration is the safest and most recommended method because it never lets the surface rise above 41°F. Running-water and microwave thawing are faster but carry time limits and follow-through requirements precisely because they expose the food to warmer conditions. What the Code does NOT permit is leaving frozen food out at room temperature, which lets the exterior sit in the danger zone for hours while the interior thaws — the single most common thawing mistake.
Why thawing is a food-safety step, not just a convenience
Thawing looks passive, but it is one of the riskier moments in food handling because a frozen item does not thaw evenly. The outer layer warms first and can climb into the temperature danger zone — 41°F to 135°F — while the center is still solid. If the whole item is left in warm conditions until the middle thaws, the outside may spend hours in the range where bacteria multiply.
That is the reasoning behind every rule in §3-501.13: keep the already-thawed portions cold, or keep the total time short, so the surface never gets a long stay in the danger zone. Understanding that single idea makes the four methods make sense — each one is a different way of protecting the outside of the food while the inside catches up. For the danger-zone concept that drives the rule, see our guide to the temperature danger zone.
Method 1: Under refrigeration
The safest method is thawing UNDER REFRIGERATION that keeps the food at 41°F (5°C) or below the entire time. Because the refrigerator never lets the surface rise above 41°F, the food never enters the danger zone at all during thawing.
The trade-off is time: refrigerator thawing is slow and requires planning a day or more ahead for large items. Two practical rules go with it. Place the thawing item on the LOWEST shelf, below and away from ready-to-eat foods, so any liquid that drains off cannot drip onto and contaminate other food. And put it in a container to catch that runoff. Refrigeration is the method to default to whenever time allows, precisely because it removes the danger-zone risk instead of merely limiting it.
Method 2: Under running water
The second method, set out in §3-501.13, is thawing COMPLETELY SUBMERGED UNDER RUNNING WATER, and it has specific parameters that are frequently tested. The water must be 70°F (21°C) OR BELOW. There must be sufficient water VELOCITY to agitate the food and float off loose particles in an overflow. And the food may only be thawed this way for a limited time — the thawed portions of ready-to-eat food may not rise above 41°F, and thawed portions of raw animal food that will be cooked may not stay above 41°F for more than 4 hours, counting the time under running water and the time needed to prepare it for cooking.
The running water does real work: it continuously carries warmth away from the food's surface and washes off loosened material, which is why still water in a sink does not qualify. The cool temperature and the time limit exist because this method deliberately exposes the food to warmer conditions than a refrigerator, so it has to be actively managed and finished promptly. For the cooking that often follows immediately, see our guide to minimum cooking temperatures.
| Method | Key requirement |
|---|---|
| Refrigeration | Keep food at 41°F (5°C) or below throughout |
| Running water | Submerged, water 70°F (21°C) or below, moving with enough velocity; time-limited |
| Part of cooking process | Cook from frozen straight to required temperature, no separate thaw |
| Microwave | Only if cooked immediately afterward, with no interruption |
| Room temperature (NOT allowed) | Leaves the surface in the danger zone for hours |
Method 3: As part of the cooking process
The third method is thawing AS PART OF THE COOKING PROCESS. Here the frozen food is cooked directly from its frozen state, with no separate thaw step, as long as the cooking brings the food to the required internal temperature for that food. A frozen burger patty dropped straight onto the griddle and cooked to its required temperature is thawing as part of cooking.
This method is safe because the food moves from frozen straight through the danger zone under active heat, spending minimal time in the risky range and finishing at a temperature that destroys pathogens. The only requirement is that the cooking actually achieves the food's required minimum internal temperature — the thaw is not a separate stage to be managed, but simply the front end of a proper cook.
Method 4: In a microwave
The fourth method, also under §3-501.13, is thawing IN A MICROWAVE OVEN, permitted only when the food is thawed in the microwave and then IMMEDIATELY TRANSFERRED to conventional cooking equipment with NO INTERRUPTION in the process. Microwave thawing followed immediately by cooking is treated, in effect, as the front end of the cooking process.
The immediacy requirement is the whole point. A microwave heats unevenly and warms the surface of the food into the danger zone, so a microwave-thawed item that is set aside — even briefly — has exactly the danger-zone exposure the Code is trying to prevent. Thaw in the microwave only when you are ready to cook right now, and move the food directly to the heat. For the reheating rules that use the same microwave discipline in a different context, see our guide to reheating TCS foods for hot holding.
Why room-temperature thawing is prohibited
The method the Code pointedly does NOT allow is leaving frozen food out at ROOM TEMPERATURE to thaw — on a counter, in a sink of still water, or anywhere the surface can warm freely. It is the most common thawing error and the most dangerous.
The problem is uneven thawing again: at room temperature, the outer layer of the food reaches the danger zone and can stay there for hours while the center is still frozen. Every one of those hours is time for bacteria on the surface to multiply, and some pathogens produce heat-stable toxins that later cooking will not destroy. None of the four approved methods allows this because each is built to keep the surface either cold or moving quickly through the danger zone. Room-temperature thawing does the opposite. For how time can be tracked and limited as its own control in related situations, see our guide to date marking of ready-to-eat TCS foods.
Frequently Asked Questions
- What are the four approved thawing methods?
- Under FDA Food Code §3-501.13: (1) under refrigeration at 41°F (5°C) or below; (2) completely submerged under running water at 70°F (21°C) or below, moving with enough velocity to float off loose particles, and time-limited; (3) as part of the cooking process, cooking the food directly from frozen to its required temperature; and (4) in a microwave, only if the food is cooked immediately afterward with no interruption. Leaving food to thaw at room temperature is not permitted.
- Why is refrigerator thawing the safest method?
- Because it keeps the food at 41°F (5°C) or below the entire time, so the food never enters the temperature danger zone during thawing at all. The other methods deliberately expose the food to warmer conditions and therefore carry time limits or immediate-cooking requirements. The trade-off with refrigeration is speed — it is slow and needs planning ahead — but it removes the danger-zone risk rather than just limiting it. Place the item on the lowest shelf in a container to catch runoff.
- What are the requirements for thawing under running water?
- The food must be completely submerged under running water at 70°F (21°C) or below, with enough water velocity to agitate the food and float off loose particles in an overflow. It is time-limited: thawed portions of ready-to-eat food may not rise above 41°F, and thawed portions of raw animal food to be cooked may not stay above 41°F for more than 4 hours, counting time under the water and time to prepare for cooking. Still water in a sink does not qualify — the water must be running.
- Can I cook food straight from frozen?
- Yes. Thawing as part of the cooking process is an approved method under §3-501.13: the frozen food is cooked directly, with no separate thaw step, as long as the cooking brings it to its required minimum internal temperature. A frozen patty cooked straight to its required temperature is thawing as part of cooking. This is safe because the food passes from frozen through the danger zone under active heat and finishes at a pathogen-killing temperature.
- Can I thaw food in the microwave?
- Yes, but only if the food is cooked immediately afterward with no interruption in the process. Microwave thawing is treated as the front end of cooking. Because a microwave heats unevenly and warms the surface into the danger zone, a microwave-thawed item that is set aside — even briefly — has the exposure the Code is designed to prevent. Thaw in the microwave only when you are ready to cook right now and move the food directly to the heat.
- Why can't I thaw food on the counter?
- Because room-temperature thawing lets the outer layer of the food sit in the temperature danger zone for hours while the center is still frozen, giving surface bacteria time to multiply — and some produce heat-stable toxins that later cooking will not destroy. It is the most common and most dangerous thawing mistake. Every approved method keeps the surface either cold or moving quickly through the danger zone; leaving food out at room temperature does the opposite.
Bottom Line
FDA Food Code §3-501.13 approves FOUR thawing methods and rules out room-temperature thawing. The methods are: UNDER REFRIGERATION at 41°F (5°C) or below throughout — the safest, because the food never enters the danger zone; UNDER RUNNING WATER at 70°F (21°C) or below, fully submerged, moving with enough velocity to float off loose particles, and time-limited so thawed portions do not stay above 41°F too long; AS PART OF THE COOKING PROCESS, cooking straight from frozen to the required internal temperature with no separate thaw; and IN A MICROWAVE, only when the food is cooked IMMEDIATELY afterward with no interruption. The common thread is that thawing must never let the surface of the food linger in the danger zone while the center catches up. Refrigeration removes that risk entirely; running water and microwave thawing manage it with cool temperatures, movement, time limits, and immediate follow-through. What the Code forbids is ROOM-TEMPERATURE thawing on a counter or in still water, which leaves the exterior in the danger zone for hours and is the most common thawing error. For related topics, see our guides to the temperature danger zone, minimum cooking temperatures, and reheating TCS foods for hot holding.
Source: FDA Food Code 2022 — §3-501.13 Thawing · FDA Food Code §3-501.13 as adopted — Thawing (full text) · University of Minnesota Extension — Time and Temperature Control