When must potentially hazardous foods be discarded based on refrigerator temperature?

Potentially hazardous foods must be handled with care to ensure food safety and prevent foodborne illness. The critical temperature range for storing these foods is between 41°F and 135°F, known as the danger zone, where bacteria can multiply rapidly.

In terms of refrigerator temperature, if the temperature rises above 40°F, potentially hazardous foods begin to enter this danger zone. Therefore, foods stored in a refrigerator that reaches temperatures above 50°F should be discarded because there is a significant risk of bacterial growth that can lead to foodborne illnesses.

Conversely, a temperature below 32°F can result in freezing, which can damage the texture and quality of food items, though it may not compel immediate discarding—it's more about quality than safety here, hence leading to the idea that foods might not need to be discarded strictly based on this temperature unless prolonged exposure occurs.

Thus, when considering these factors, the answer that correctly indicates when potentially hazardous foods need to be discarded based on refrigerator temperature encompasses both the risk of temperatures above 50°F and the complications of freezing temperatures.