We have all heard about the five-second rule. If you drop a piece of food on the ground or any surface that looks reasonably sanitary, it is justifiable to pick it up and continue eating as if nothing had happened. The rule is not traditionally taught by a teacher, but it might have been mentioned by elementary school peers. Perhaps even a parent was the one to explain the rule, but it cannot be guaranteed that scientists will ever find enough scientific evidence to prove the rule.
The length of exposure affects the amount of bacteria allowed to transfer onto a morsel of food. However, it is entirely inaccurate that less than five seconds of contact protects you from any and all bacteria.
A study conducted by Donald Schaffner and Robyn Miranda at Rutgers University proved that there are a multitude of factors other than time which affect the transfer of bacteria, such as the type of food and the surface which it falls upon. To conduct their research, Schaffner and Miranda varied scenarios of food falling onto given surfaces with different bacteria for designated periods of time.
Altogether, their study bore 2,560 measurements of data, a sizeable number whose conclusion cannot be ignored for the sake of a children’s schoolyard tale.
One particularly interesting finding was how bacteria transferred from the ground to the piece of food. “Transfer of bacteria from surfaces to food appears to be affected most by moisture,” Schaffner said. “Bacteria don’t have legs, they move with the moisture, and the wetter the food, the higher the risk of transfer.”
Regarding the surface upon which the food falls, the study concluded that the texture does make a difference. Carpeted surfaces have a comparatively low bacteria transfer rate in relation to tile and stainless, while results for wooden surfaces varied.
In truth, all contact between any kind of food with any kind of surface for however long will undoubtedly cause contamination. The only variable to that absolute is the level of contamination, and thus the likelihood of actual infection as a result.
The five-second rule revelation is not a recent one, with many researchers being quoted as against the integrity of the rule.
Dr. Jorge Parada, medical director of the Infection Prevention and Control Program at Loyola University Health System, was quoted saying in 2014, “When it comes to folklore, the ‘five-second rule’ should be replaced with ‘When in doubt, throw it out.’”
Parada asserted that one must consider not only the unknowns of the environment, but also one’s personal receptivity to bacteria and sensitivity to the bodily invaders.
As it turns out, the five-second rule is nothing more than a justification for a lazy habit, that should have its consequences considered.