The “Official” 5 second rule
That’s it, it’s now been standardized!
This rule applies to foods, particularly solid foods like cookies, that have fallen to the ground. The rule states that any germs that can be contracted by grounded food in under five seconds are of such a small amount that they will easily be destroyed by gastric acid, thus causing no harm to the body. The rule provides a convenient rationale for eating food off the floor, and is usually invoked when a group of people are present (as a polite fiction). Thus, for example, a person might drop a dry jelly bean, pick it up quickly, tell his friends “five second rule” and then eat the candy.
The five-second rule is seldom invoked in the case of sticky foods, such as ice cream, cold cuts, or jelly beans which have been moistened, particularly if visibly dirty.
Read it in its entirety at Wikipedia
