Make sure the frozen ground beef is in a leak-proof package or plastic bag. To thaw the ground beef, submerge the bag in cold tap water — never use warm or hot water, as that can cause the outer layer of the food to heat up to a temperature where harmful bacteria begins to multiply.

2 hours

Definitely not. Beef already has microorganisms in the package when you buy it, just not dangerous amounts of them. When you leave it at room temp all day (or even just 2–3 hours), they have plenty of time to replicate into what ARE dangerous amounts.

Meat provides the ideal environment for bacteria to breed, so the U.S. Department of Agriculture cautions consumers against thawing raw meat at room temperature. In fact, raw meat should never sit out in temperatures above 40 F for extended periods of time – and never longer than two hours for any reason.

two hours

Cooked food sitting at room temperature is in what the USDA calls the “Danger Zone,” which is between 40°F and 140°F. In this range of temperatures, bacteria grows rapidly and the food can become unsafe to eat, so it should only be left out no more than two hours.

Perishable food (like chicken and other meats) should be tossed if left out at room temperature more than two hours (much less if in a warm room). If the food is not kept warm in chafing dishes (or stored on ice, when served cold), it is no longer safe to eat after two hours of sitting on the table.

Bacteria grow most rapidly in the range of temperatures between 40 °F and 140 °F, doubling in number in as little as 20 minutes. This range of temperatures is often called the “Danger Zone.” Never leave food out of refrigeration over 2 hours.

The FDA recommends that all perishables left at room temperature for more than two hours be discarded. Bacteria grow most rapidly between 40 degrees Fahrenheit (4.4 degrees Celsius) and 140 degrees Fahrenheit (60 degrees Celsius), doubling in amount every 20 minutes.

between 40 °F and 140 °F