Five-second rule
From Wikipedia, the free encyclopedia
The five-second rule is a popular polite fiction regarding the eating of food that has fallen to the floor or ground. The origins of the rule are unknown. The substance of the rule is that if food falls on the ground, it may be safely eaten as long as it is picked up within 5 seconds.
There are many variations on the rule. Sometimes the time limit is modified so that it is known variously as the "three-second rule", "seven-second rule", "the five-minute rule" etc. In some variations, the person picking up the food arbitrarily extends the time limit based on the actual amount of time required to retrieve the food. This also can vary based on the surface on which the food was dropped. In Russia the rule is formulated as simple as "Promptly picked up is not considered fallen".
[edit] Research
Although it has received little scholarly attention, the five-second rule has been studied as both a public health recommendation and as a sociological effect.
In 2003, intern Jillian Clarke of the University of Illinois found in a survey that 56% of the men and 70% of the women surveyed were familiar with the five-second rule, and determined that a variety of foods were significantly contaminated by even brief exposure to a tile inoculated with E.coli;[1] on the other hand, Clarke also found no significant evidence of contamination on public flooring.[2] Clarke received the 2004 Ig Nobel Prize in public health (a parody award) for this work.[3]
A more thorough study in 2006 using salmonella on wood, tiles, and nylon carpet found that the bacteria were still thriving after twenty-eight days of exposure under dry conditions.[4] Tested after eight hours' exposure, the bacteria could still contaminate bread and bologna in under five seconds, but a minute-long contact increased contamination about tenfold (with tile and carpet surfaces only).[5]
The five-second rule was also featured in an episode of the Discovery Channel series MythBusters. There was no significant difference in the number of bacteria collected from 2 seconds exposure as there was from 6 seconds exposure. The moisture, surface geometry and the location the food item was dropped on did however affect the number of bacteria. [6]
[edit] See also
[edit] References
- ^ Articles on the experiment conducted by Jillian Clarke and Meredith Agle: Newhousenews, UIUC
- ^ Agle, Meredith (2003-09-02). "If You Drop It, Should You Eat It? Scientists Weigh In on the 5-Second Rule". ACES News, University of Illinois College of Agricultural, Consumer, and Environmental Sciences. http://www.aces.uiuc.edu/news/stories/news2467.html. Retrieved on 2008-04-24.
- ^ Winners of the Ig Nobel Prize: The 2004 Ig Nobel Prize Winners
- ^ Dawson, P.; I. Han, M. Cox , C. Black, and L. Simmons (April 2007). "Residence time and food contact time effects on transfer of Salmonella Typhimurium from tile, wood and carpet: testing the five-second rule". Journal of Applied Microbiology 102 (4): 945–953. doi:.
- ^ McGee, Harold (2007-05-09). "The Five-Second Rule Explored, or: How Dirty Is That Bologna?". New York Times. http://www.nytimes.com/2007/05/09/dining/09curi.html?ex=1336449600&en=706e4f0cec07d005&ei=5124&partner=permalink&exprod=permalink. Retrieved on 2007-05-09.
- ^ "Annotated mythbusters: episode 39". http://kwc.org/mythbusters/2005/10/mythbusters_chinese_invasion_a.html. Retrieved on 2008-08-17.
