Gsquared
06-13-2007, 08:02 AM
The Five Second Rule: Myth or Fact?
Ever dropped a cookie on the floor, yelled "five-second rule," then quickly picked it up and popped it into your mouth? Theassumption is that five seconds is not a long enough time for your food to pick up harmful bacteria. The exact origin of this urban legend is unknown, but supposedly, Genghis Khan was the first to make such a claim, specifying a lenient 12 to 20 hour period for food left on the ground to remain safe. The fast food industry also has been credited with the "rule," supposedly to help minimize food waste. Whatever its origin, the "5 second rule" has become a readily accepted practice by young and old alike, especially to rationalize the eating of sweet foods like cookies that have fallen to the ground.
Rule Put to the Test
Last summer, Jillian Clarke, a high school student doing an apprenticeship at Hans Blaschek's University of Illinois laboratory decided to test the validity of the 5-second rule. Clarke first surveyed 100 college students (50 male, 50 female) to see what they knew about the rule. Of those surveyed, 70% of the women and 56% of the men were familiar with and had used the 5-second rule. Cookies and candies were much more likely to be picked up and eaten than items such as cauliflower or broccoli. Clarke then took swab samples from floors around campus to determine bacterial counts. The floors were surprisingly clean. Next, Clark inoculated rough and smooth floor tiles with E. coli bacteria. She placed Gummy Bears and fudge striped cookies on the inoculated floor tiles for 5 seconds, then examined the foods under a high-powered microscope. Her findings showed that in all cases E. coli was transferred from the tile to the food, demonstrating that microorganisms CAN be transferred from ceramic tile to food in 5 seconds or less. Clark found that more E. coli was transferred from smooth tiles than from rough tiles and that both the dry cookies and the gummy bears became contaminated with only 5 seconds of contact with the inoculated tiles.
Old Habits Die Hard
Clarke's findings show there are no assurances that any type of dropped food is safe for any amount of time. Because germs are microscopic, there is no way to know what is growing on your floors. While it is likely that a bathroom floor may be more risky than a kitchen floor, one needs to assume that harmful bacteria may be present on any surface. It is time to re-think this age-old practice and stop rationalizing the use of the 5-second rule. As tempting as it may be, the next time some yummy morsel falls to the floor…into the trash it must go!
Ever dropped a cookie on the floor, yelled "five-second rule," then quickly picked it up and popped it into your mouth? Theassumption is that five seconds is not a long enough time for your food to pick up harmful bacteria. The exact origin of this urban legend is unknown, but supposedly, Genghis Khan was the first to make such a claim, specifying a lenient 12 to 20 hour period for food left on the ground to remain safe. The fast food industry also has been credited with the "rule," supposedly to help minimize food waste. Whatever its origin, the "5 second rule" has become a readily accepted practice by young and old alike, especially to rationalize the eating of sweet foods like cookies that have fallen to the ground.
Rule Put to the Test
Last summer, Jillian Clarke, a high school student doing an apprenticeship at Hans Blaschek's University of Illinois laboratory decided to test the validity of the 5-second rule. Clarke first surveyed 100 college students (50 male, 50 female) to see what they knew about the rule. Of those surveyed, 70% of the women and 56% of the men were familiar with and had used the 5-second rule. Cookies and candies were much more likely to be picked up and eaten than items such as cauliflower or broccoli. Clarke then took swab samples from floors around campus to determine bacterial counts. The floors were surprisingly clean. Next, Clark inoculated rough and smooth floor tiles with E. coli bacteria. She placed Gummy Bears and fudge striped cookies on the inoculated floor tiles for 5 seconds, then examined the foods under a high-powered microscope. Her findings showed that in all cases E. coli was transferred from the tile to the food, demonstrating that microorganisms CAN be transferred from ceramic tile to food in 5 seconds or less. Clark found that more E. coli was transferred from smooth tiles than from rough tiles and that both the dry cookies and the gummy bears became contaminated with only 5 seconds of contact with the inoculated tiles.
Old Habits Die Hard
Clarke's findings show there are no assurances that any type of dropped food is safe for any amount of time. Because germs are microscopic, there is no way to know what is growing on your floors. While it is likely that a bathroom floor may be more risky than a kitchen floor, one needs to assume that harmful bacteria may be present on any surface. It is time to re-think this age-old practice and stop rationalizing the use of the 5-second rule. As tempting as it may be, the next time some yummy morsel falls to the floor…into the trash it must go!