What is the recommended maximum time food can be left out at room temperature before it's unsafe?

The recommended maximum time food can be left out at room temperature before it becomes unsafe is two hours. This guideline is based on the understanding that food is in the "danger zone" between 40°F and 140°F, where bacteria can multiply rapidly. In general, food that has been left out in this temperature range for longer than two hours is at a higher risk for foodborne illness.

When food is left out beyond this time frame, the potential for pathogenic bacteria growth increases significantly, which can lead to foodborne illnesses if consumed. Certain factors, such as the type of food and the ambient temperature, may affect the safety of food left out; however, the two-hour rule is a widely recognized standard. After two hours, it is advisable to refrigerate or discard perishable foods to minimize health risks.