The 5-second rule is based on the theory that food that has been dropped on the floor for a brief period of time does not pick up many germs and is safe to eat. This theory is somewhat true in that the less time food is in contact with a surface, the fewer bacteria are transferred to the food. Several factors play a role in the level of contamination that may occur once food has been dropped on the floor or other surface. These factors include the texture of the food (soft, sticky, etc.) and the type of surface (tile, carpet, etc.) involved. It is always best to avoid eating food that has a high risk of contamination, such as food that has been dropped in the trash.