How long can milk stay unrefrigerated?

Milk should be kept refrigerated whenever possible and should be discarded if it spends more than two hours at temperatures above 40 degrees Fahrenheit. If a refrigerator loses power, it can maintain the safety of milk and other foods for up to four hours as long as it remains closed.

Any time milk spends at room temperature increases the chance of bacterial growth and can speed the process of spoilage. When shopping, it's a good idea to select dairy products toward the end of the visit in order to minimize the amount of time milk spends in the dangerous temperature zone.