What is the maximum time food can be in the 135 to 170 degree range?

Food should not be kept in the range of 135 to 140 degrees Fahrenheit for more than an hour; heating food to 165 degrees Fahrenheit kills any bacteria and is safe to consume. The 40 degrees to 140 degrees Fahrenheit range is considered a "danger zone" in which bacteria can multiply rapidly.

When foods are cooked but are not eaten within this time frame, they can be safely kept at 140 F or above without risk of bacterial spoilage or illness. How long foods are held at these temperatures before being eaten depends largely on the food and how long it can withstand heat without becoming dried out or having other adverse changes to its quality.