The food temperature danger zone refers to measurements in temperature at which harmful bacteria can quickly grow on food, even food that has been cooked to safe levels beforehand. For instance, when you cook a raw chicken to at least 180 degrees F (82.22 C), it is safe to eat. However when you leave that same cooked chicken out on the counter for several hours it may reach the danger zone and be no longer safe to consume, even if you reheat it.
Most define the temperature danger zone as between 40-140 degrees F (4.44-60 C). Allowing food to hit this danger zone means you should discard it. Some might ask, does that mean all food? Actually it applies mostly to cooked or prepared food and any foods that require refrigeration. You don’t need to keep apples at below 40 degrees F, though they will keep longer if you refrigerate them.
Any dairy products, many vegetables, all meat and fish, and things like eggs should be refrigerated as soon as you get them home. Many canned or jarred products like tomato sauce, peanut butter or salsa, also require refrigeration as soon as they are open. Naturally, your refrigerator should be set below 40 degrees F to make sure food is not being stored in the danger zone.
Most often though, people use the temperature zone as a means of determining when to refrigerate cooked food. Since bacteria will thrive in this zone, any food left out too long should be suspicious and shouldn’t be consumed. The US Centers for Disease Control have some interesting statistics on food poisoning. Over 70 million people get food poisoning each year.
Most of these cases are not the huge newsworthy cases of contaminated food. Instead they are incidents where people get sick from food they have not stored properly. Many people confuse food poisoning with stomach flu, and don’t report symptoms. Yet, we could do a lot by keeping food outside of the temperature danger zone to help reduce these illnesses.
One way to determine if food should be refrigerated yet is to keep a clean meat thermometer in it. This will work well with most meat. If you note internal temperature dropping into the temperature danger zone, you can transfer food to the fridge. Others say that most cooked foods should be refrigerated within a couple hours of cooking.
When you serve things like cooked meat again, or luncheon meats, you should heat them to over 165 degrees, even if they were fully cooked before. However when food has been improperly stored, this may not be enough to kill all bacteria. Don’t risk it if you think food may have sat too long at unsafe temperatures. It is simply not worth a case of food poisoning to eat food that might have been improperly stored.