Five Second Rule

A common misconception that has become a general practice when food has been dropped on the floor or ground. The belief is that any food dropped can be eaten if it has been picked up before 5 seconds has elapsed, since it is believed that the food cannot be contaminated that quickly. This theory is incorrect, since microorganisms of bacteria can immediately become attached to dropped food, especially if the area around the dropped food is moist. Although the risk of the food becoming contaminated with bacteria may be minimal if dropped onto a relatively clean surface, the risk is still present so it is best to discard the dropped item.