Time and temperature are two of the most important control factors used to in the prevention of a food borne illness. There are many steps during the process of preparing and serving food in which time and temperature must be controlled. Harmful microorganisms grow well in foods held between temperatures of 41° degrees Fahrenheit and 135° degrees Fahrenheit. This temperature range is also known as the Temperature Danger Zone (TDZ). The less time foods spend in the TDZ, the less time harmful microorganisms have to grow. Typically, harmful microorganisms can grow to levels high enough to cause illness within four hours.
The U. S. Food and Drug Administration (FDA) publishes the Food Code, a model that assists food control jurisdictions at all levels of government by providing them with a scientifically sound technical and legal basis for regulating the retail and food service segment of the industry. Local, state, tribal, and federal regulators use the FDA Food Code as a model to develop or update their own food safety rules and to be consistent with national food regulatory policy.
Many types of foods can become unsafe and cause people to become ill. Some foods, known as PHFs, are at higher risk for growing harmful microorganisms; it is these microorganisms that cause a food borne illness. The use of time and temperature are important in establishing critical establishing the parameters for food safety.
When a source of heat is available, hold hot foods at 135° degrees Fahrenheit or higher and check the temperature every four hours. If the temperature of the food at four hours is less than 135° degrees Fahrenheit, the food must be discarded. It is permissible to hold hot food without temperature controls for up to four hours if the following conditions are met:
Hold cold foods at 41 degrees Fahrenheit or less and check the temperature every four hours. If the temperature of the food at four hours is greater than 41° degrees Fahrenheit, the food must be discarded.
It is permissible to hold cold food without temperature controls for up to six hours if the
following conditions are met: