Does the 5-Second Rule Work?

According to the so-called rule, it is OK to eat food you drop on the floor or another contaminated surface as long as you pick it up in less than 5 seconds. 

However, scientists have put this rule to the test and discovered that some germs immediately attach themselves to food after coming into contact with contaminated surfaces. For example, salmonella bacteria can linger for up to a month on a contaminated surface, forming spores that can live for years. Eating food that has been dropped on such surfaces can make you very sick.

• A floor that looks clean is not necessarily clean. Even dry floors that look clean can still harbor bacteria. That is because some bacteria can survive for a long time and are invisible. So there is a good chance that your kitchen floor or school cafeteria floor has some bacteria that is still living on it.
• The faster you pick it up, the better. The longer a piece of food sits on the floor, the more bacteria it picks up. That means that food that is left on the floor for less than 5 seconds may have less bacteria on it than food that is left out for longer.
• However, 5 seconds may not be enough. As soon as your food touches the ground, bacteria can cling to it. So even if you pick it up very quickly, food that has touched the floor can still be contaminated. In a 2016 study, scientists tested the 5-second rule by throwing watermelon, plain bread, buttered bread, and chewing gum on various surfaces. Watermelon sucked up the most bacteria, as bacteria can migrate swiftly through the wet surfaces.
• Throw it out when in doubt. While not all bacteria are harmful, others can have terrible effects, such as diarrhea or even hepatitis. Since it doesn’t take much to make you sick, your safest option is to simply throw away any food that has dropped to the ground.