The hot dog that rolls off the plate, the baby’s cookie that falls on the floor, the candy bar that slides across the table–we’re told we have five seconds to pick it up before it’s contaminated. Is this true?
Researcher Jorge Parada says, "A dropped item is immediately contaminated and can’t really be sanitized. When it comes to folklore, the ‘five-second rule’ should be replaced with ‘when in doubt, throw it out.’"
All items that come into contact with a surface pick up bacteria (and dirt!). How much bacteria and what kind of microbes depends on the object dropped and the surface it is dropped on.