What are the FDA guidelines for room temperature?

January 1, 2026 •

4 min read

According to the FDA, perishable foods must not be left at room temperature for more than two hours to prevent rapid bacterial growth. However, the specific FDA guidelines for room temperature differ significantly depending on whether you are handling food or storing pharmaceuticals.

Quick Summary

The FDA defines room temperature differently for food safety and pharmaceuticals. For food, the key is avoiding the "Danger Zone" (40°F–140°F), while drugs follow a United States Pharmacopeia standard for controlled temperature.

Key Points

Food Safety Danger Zone: The FDA defines a food "danger zone" between 40°F and 140°F where bacteria thrive.
2-Hour Rule: Perishable food should not be left at room temperature for more than two hours, or one hour if the temperature is above 90°F.
Controlled Room Temperature (CRT): For pharmaceuticals, CRT is defined by USP as 20°C to 25°C (68°F to 77°F), with controlled excursions.
Avoid Improper Storage: The guidelines for medications are designed to prevent chemical degradation and loss of potency, which can result from improper temperature exposure.
Thaw Safely: Never thaw food on the counter. Always use safe methods like refrigeration, cold water, or a microwave.
Check Product Labels: Always refer to specific storage instructions on a product's packaging, as they can override general guidelines based on stability testing.

Food Safety: The "Danger Zone"

For consumer food safety, the FDA's primary concern regarding room temperature is the "Danger Zone," which is the temperature range between 40°F (4°C) and 140°F (60°C). Within this range, bacteria that can cause foodborne illness multiply rapidly. To minimize risk, perishable foods must adhere to the "2-Hour Rule": they should not be left out at room temperature for more than two hours.

The 2-Hour Rule and its Exceptions

Standard Rule: Discard any perishable food left out for more than two hours.
Hot Weather Exception: If the ambient temperature is 90°F (32°C) or higher, the safe time for food to be left out is reduced to just one hour.

Proper Food Handling at Room Temperature

The FDA emphasizes proper food handling to avoid the dangers of temperature abuse. The guidelines are designed to minimize the time food spends in the temperature danger zone during various stages of handling.

Grocery Shopping: Put refrigerated and frozen items away as soon as you get home. Do not let groceries sit in a hot car for more than two hours, or one hour if temperatures are above 90°F.
Leftovers: Divide large quantities of hot leftovers into shallow containers before refrigerating to facilitate quicker cooling. Reheat leftovers to an internal temperature of 165°F.
Thawing Food: Never thaw perishable food on the counter at room temperature. Safe methods include thawing in the refrigerator, in cold water (changing the water every 30 minutes), or in the microwave.
Marinating: Always marinate food in the refrigerator, not on the counter.

Pharmaceutical Products: Controlled Room Temperature (CRT)

Unlike the flexible definition for food, the guidelines for pharmaceuticals are far more precise and regulated. The FDA typically references standards from the United States Pharmacopeia (USP) for drug storage. The key term here is Controlled Room Temperature (CRT).

Defining Controlled Room Temperature

Standard Range: USP defines CRT as a thermostatically controlled temperature range of 20°C to 25°C (68°F to 77°F).
Permitted Excursions: Transient temperature excursions between 15°C and 30°C (59°F and 86°F) are allowed, provided the drug's mean kinetic temperature (MKT) does not exceed 25°C.
Excessive Heat: Transient spikes up to 40°C (104°F) are permitted for up to 24 hours, but only if the manufacturer's stability data supports it.

Importance for Drug Stability

Maintaining CRT is critical for preserving a drug's efficacy and safety. Improper storage can lead to:

Chemical Degradation: The active ingredients can break down, rendering the medication less effective.
Physical Changes: The drug's physical properties may change, such as crystallization or separation of components.
Recall Risk: Failure to follow storage guidelines can lead to regulatory violations and product recalls.

General Storage Tips for Medications

Most pharmaceuticals should be stored in a cool, dry place away from direct sunlight, moisture, and extreme temperatures. This is why the bathroom medicine cabinet is often an unsuitable location due to humidity fluctuations. Always refer to the specific instructions on the drug's packaging or consult a pharmacist. Find the FDA's latest information on safe food handling here.

Comparison: FDA Guidelines for Food vs. Pharmaceuticals


Feature	Food Safety	Pharmaceutical Storage
Key Principle	Avoid the "Danger Zone" (40°F–140°F) to prevent bacterial growth.	Maintain Controlled Room Temperature (20°C–25°C) to ensure chemical stability.
Standard Range	Any temperature between 40°F and 140°F is unsafe for perishable items over time.	20°C–25°C (68°F–77°F) with tightly controlled excursions.
Time Limit at Room Temp	Maximum of 2 hours, or 1 hour if above 90°F.	Storage at CRT is intended for long-term stability according to expiration dating.
Primary Concern	The multiplication of harmful bacteria causing foodborne illness.	The chemical and physical degradation of the drug, which can reduce its effectiveness or safety.
Regulatory Standard	Governed by the FDA Food Code and other public health guidance.	Governed by standards like USP General Chapter <659> and ICH Guidelines.

Conclusion

Understanding the nuanced FDA guidelines for room temperature is crucial for both consumer safety and proper product handling within the pharmaceutical industry. The term is not one-size-fits-all, with guidelines differentiating sharply between perishable food and shelf-stable medication. For food, the rapid growth of bacteria dictates strict time limits within the temperature "Danger Zone" of 40°F to 140°F. For drugs, controlled room temperature (CRT) protocols are centered on maintaining a narrow, stable range of 20°C to 25°C to preserve chemical integrity over time. Following these specific guidelines is essential for preventing illness from contaminated food and ensuring medications remain safe and effective.

Ultimately, whether you are handling leftovers or storing prescription drugs, the principle is the same: temperature control is vital. By paying close attention to the distinct rules for each category, consumers and healthcare professionals can prevent foodborne illness and maintain the therapeutic benefits of medications as intended by the manufacturer.

Frequently Asked Questions

The FDA defines the food danger zone as the temperature range between 40°F and 140°F. This is the range where harmful bacteria can multiply most rapidly.

Perishable food should not be left out at room temperature for more than two hours. This time limit is reduced to one hour if the ambient temperature is 90°F or higher.

Controlled Room Temperature (CRT), a standard referenced by the FDA, is defined by the USP as a thermostatically maintained environment between 20°C and 25°C (68°F to 77°F), with specific allowances for brief temperature excursions.

No, it is generally not recommended to store medicine in a bathroom cabinet. The high humidity and temperature fluctuations in a bathroom can compromise the stability and effectiveness of many drugs.

The FDA recommends three safe methods for thawing: in the refrigerator, in cold water (changing the water every 30 minutes), or in the microwave. Thawing on the counter is unsafe.

Improper temperature storage can lead to the degradation of a drug's active ingredients, changes in its physical properties, and a potential loss of therapeutic effectiveness. This can pose significant health risks.

During a power outage, keep the refrigerator and freezer doors closed as much as possible. A refrigerator will keep food cold for about 4 hours if unopened. Any perishable food left above 40°F for more than 2 hours should be discarded.