The Danger Zone

(Adapted from

Assistance with meals is an important part of the care and services provided in an assisted living or residential care Community.  Understanding the “danger zone” of food temperatures is a critical part of ensuring safe food handling.  The following is adapted from the USDA Fact Sheet “Safe Food Handling”:

Bacteria exist everywhere in nature. They are in the soil, air, water and the foods we eat. When they have nutrients (food), moisture, time and favorable temperatures, they grow rapidly increasing in numbers to the point where some can cause illness. Therefore, understanding the important role temperature plays in keeping food safe is critical. If we know the temperature at which food has been handled, we can then answer the question, “Is it safe?”

The “Danger Zone” (40 °F-140 °F)
Bacteria grow most rapidly in the range of temperatures between 40 ° and 140 °F, doubling in number in as little as 20 minutes. This range of temperatures is often called the “Danger Zone.” That’s why the Meat and Poultry Hotline advises consumers to never leave food out of refrigeration over 2 hours. If the temperature is above 90 °F, food should not be left out more than 1 hour.

Storing Leftovers
One of the most common causes of foodborne illness is improper cooling of cooked foods. Because bacteria are everywhere, even after food is cooked to a safe internal temperature, they can be reintroduced to the food and then reproduce. For this reason leftovers must be put in shallow containers, for quick cooling and refrigerated within 2 hours.

Foods should be reheated thoroughly to an internal temperature of 165 °F or until hot and steaming. In the microwave oven, cover food and rotate so it heats evenly. Follow manufacturer’s instructions for stand time for more thorough heating. In the absence of manufacturer’s instructions, at least a two minute stand time should be allowed.

Cold Storage Temperatures
Properly handled food stored in a freezer at 0 °F will always be safe. Freezing keeps food safe by slowing the movement of molecules, causing bacteria to enter a dormant stage. Once thawed, these bacteria can again become active and multiply to levels that may lead to foodborne illness. Because bacteria on these foods will grow at about the same rate as they would on fresh food, thawed foods should be handled as any other perishable food.

A temperature of 40 °F should be maintained in the refrigerator. In contrast to freezer storage, perishable foods will gradually spoil in the refrigerator. Spoilage bacteria will make themselves known in a variety of ways. The food may develop an uncharacteristic odor, color and/or become sticky or slimy. Molds may also grow and become visible. Bacteria capable of causing foodborne illness either don’t grow or grow very slowly at refrigerator temperatures. An appliance thermometer should always be used to verify that the temperature of the unit is correct.

You can learn more about food temperatures at: How Temperatures Affect Food

Discussion Area - Leave a Comment