In This Article:
- What is the temperature danger zone?
- Time-Temperature Abuse
- Bacterial Growth in Food
- Reducing the Risk of Harmful Bacteria and Foodborne Illness
- Tools to Combat Contamination
- Frequently Asked Questions
Temperature Danger Zone
Chefs and kitchen staff know the temperatures that food should be at to kill bacteria. However, it is equally important to remember the temperatures where foods are susceptible to rapid bacterial growth. This is when they enter “the temperature danger zone,” which is anywhere between +41ºF to +135ºF. However, bacteria grows even more rapidly between 70ºF and 125ºF.
Time-Temperature Abuse
Foods reach the temperature danger zone when they are left too long within that temperature range. This is known as “time-temperature abuse.”
Time-temperature abuse quickly creates an environment for foodborne microorganisms to grow which can make guests sick. According to the Certified Food Safe Professional (CFSP) program, there are three ways time-temperature abuse can occur:
- Cooked or raw foods are not held or stored at required temperatures
- Food is not cooked or re-heated to a temperature to kill microorganisms
- Foods are not cooled properly
Bacterial Growth in Food
For bacteria to survive in food, all it needs is moisture, heat, and oxygen. The temperature danger zone is the most ideal environment to get all three. When the environment is right, bacteria will multiply very quickly.
Using an example from the CFSP program, bacteria can double their amounts at the following temperatures:
- +100ºF: Every 15 minutes
- +50ºF: Every 15 hours
- +36ºF: Every 15 days
- 0ºF: Most bacteria are dormant
How to Reduce Risk of Harmful Bacteria
- Avoiding time-temperature abuse and keeping foods out of the temperature danger zone at a food service reduces the risk of customers contracting a foodborne illness.
Ben Hatley, a ServSafe certified product consultant at Central Restaurant Products, advises managers to implement a cleaning schedule that tracks high touch & critical surfaces. Assigning a lead to enforce the cleaning schedule is an extra step to ensure compliance. By creating a timed schedule, you can ensure that every hour prep tables, drawer knobs and other high-contact spaces are sanitized. He recommends “combing a cleaning schedule with a ‘clean as you go’ mentality, to prevent contaminants from lingering and to emphasize the importance of cleanliness within your kitchen’s culture.”
In addition to Ben’s advice, below are ways the CFSP program suggests for operators to limit growth:
- Defrost frozen foods using one of the following methods:
- Under refrigeration at +41ºF or lower
- Submerged under running water at +70ºF
- In a microwave
- As a part of the cooking process
- Cook food until it reaches +165ºF for 15 seconds (this temperature kills bacteria)
- If holding food, keep hot foods at +135ºF and cold food under +41ºF
- Use two-stage cooling to chill leftover foods by taking them from +135ºF to +70ºF within two hours and then from +70ºF to +41ºF in four hours or less
- Keep food in wide shallow containers to allow food to obtain maximum cooling in a short period of time
- Use caution with high-protein foods as they are more susceptible to bacterial contamination–which especially includes foods that have been ground, chopped, etc. such as hamburger or eggs
- Properly cover all foods placed in a refrigerator so they are protected against contaminates above them
- If compatible with the food type or recipe, try to bring the pH level of food to an acidic state of 7.6 pH or higher by adding in ingredients such as apples, vinegar or tomatoes
- Do not let foods be out-of-refrigeration for any more than four hours of cumulative time from preparation to serving
In addition to securing food from the temperature danger zone when holding, it is also important to make sure food reaches its minimum internal temperature to reduce the risk of pathogen growth that can also result in foodborne illness. Minimum internal temperatures vary by food type, but they’re important to know.
Tools to Combat Contamination
Taking food temperatures frequently and logging them is a simple tactic to prevent time abuse and ensure compliance. There are also a wide variety of products to help food services stay out of the temperature danger zone and keep guests safe. For example, blast chillers quickly take hot food to cool food safe temperatures for storage. Meanwhile, holding cabinets & food warmers keep foods at proper warm temperatures to avoid going below the 135 degree mark. Some food service equipment & supplies have built-in antimicrobial protection with materials that kill or inhibit bacterial growth for an added protection.
Metro, a leader in storage, transport and holding equipment, offers a wide range of equipment to keep food safe and delicious. They offer both insulated and non-insulated options in full-height and half height. They even offer heated meal delivery carts to prevent temperature drops during transport.
Handouts are also available to hang in kitchens for training and keeping practices top of mind:
Download StateFoodSafety’s poster for your kitchen.
The Food Standards Modernization Act (FSMA) was passed in 2011 requiring food facilities to have accurate, reliable temperature control measures in place and expands the FDA’s authority to conduct more thorough inspections. It is imperative to keep your operation in safe, working order to keep guests safe and licenses intact.
Frequently Asked Questions
- What foods need the most care?
The National Restaurant Association has published a list of foods that have the highest risk of rapid bacteria growth. The most common are milk & dairy products, shell eggs, poultry, beef, pork, lamb, fish, shellfish, crustations, baked potatoes, cooked rice, tofu, sliced melons, sprouts and more. - Does it matter how I take the food’s temperature?
Yes! There are different types of thermometers, so make sure you have the right one. Also be sure to test the thickest section of the food for an accurate reading. - How long can food stay in the danger zone?
The U.S. Department of Agriculture advises against leaving chilled food out of refrigeration for over 2 hours and warm food (above 90°F) for over 1 hour. - What is the food danger zone in Celsius?
The temperature danger zone in Celsius is between 4°C and 60°C. - Should I take temperatures of food when receiving it from suppliers?
Yes! If food temperatures do not meet requirements, do not accept the food. This is especially important in warmer climates or summer months when food may be sitting in hot delivery trucks. - How do I keep food safe during travel?
If you are traveling with cold food, bring a cooler filled with ice or ice packs. If you are traveling with hot food, the USDA Food Safety and Inspection Service recommends cooking food in advance, then cooling it and transporting cold. - How can I safely store uneaten food or cooked ingredients?
It is best to put leftovers into shallow containers so that it can cool quickly, and then refrigerate within 2 hours.
If you have any more questions about the danger zone or products to help keep food at safe temperatures, one of our expert ServSafe certified product consultants are happy to assist! Give us a call at 800-215-9293 to learn more!
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