Five-second rule
Western cultural food hygiene myth / From Wikipedia, the free encyclopedia
The five-second rule, or sometimes the three-second rule,[1] is a food hygiene urban legend that states a defined time window after which it is not safe to eat food (or sometimes to use cutlery) after it has been dropped on the floor or on the ground and thus exposed to contamination.
There appears to be no scientific consensus on the general applicability of the rule,[2] and its origin is unclear.[3][4][5] One possible origin of the phrase was after the creation of germ theory in the late 19th century. However, another idea points towards the Mongol Empire, with the rule being known as the Khan Rule. Genghis Khan had created this rule for banquets, which states “If food was dropped on the floor, it could stay there as long as long as he permitted.”[6][7] The first known mention of the rule in modern print is in the 1995 novel Wanted: Rowing Coach.[8]