Five Second Rule

My informant explained to me the popular saying of the five second rule. He had first heard this at the age of 10 when he was in elementary school. At lunch in the cafeteria he had accidentally dropped his sandwich and his friend shouted out five second rule. He said that meant, he had 5 seconds to pick it up and eat it before he had to throw it away because there were too many germs.

He explained to me many instances where this has happened. I have gone through the same thing many times before. As early as 3rd grade I remember people telling me about the five second rule when I had dropped food, particularly solid food, on the ground.

The five second rule has been researched and proven to be false many times in the course of history. In 2005, a high school student at an internship in University of Illinois, conducted research on this particular topic of the Five Second Rule. She tested and found that there were no bacteria in clean surfaces on the ground. But she went out to found out there were significant amounts of E. coli bacteria on dirty surfaces of the ground. She also found out that when she put food on the ground the bacteria will be transferred in less than five seconds, negating the five second rule. The student went on to win an Ig Noble Price in 2004 for Public health.

Also a popular show on the Discovery Channel called MythBusters, also conducted a test of sorts trying to prove wrong the five second rule. The results they got proved the high school students findings that bacteria and other harmful things will come onto the food if dropped, in less than 5 seconds. They also went on to say that even two seconds of exposure is enough for it to transfer.

I have heard many variations from my friends. One variation I have heard is the 2 second rule and sometimes even the three second rule. I guess it differs from where you are from. My friend who told me about the 2 second rule is from the northwest region of the United States.


“Episode 39: Chinese Invasion Alarm, 5 Second Rule.” MythBusters. Discovery Channel. Feb.-Mar. 2007.

“Improbable Research.” Improb. 2006. Ig Noble Prize. 6 Apr. 2007 <>.