The Chicago Tribune reports:
Dropping a piece of food on the floor and then picking it up and dining on
it is a germaphobe's nightmare.
Streptococcus. Staphylococcus. E. coli. Oh, my!
But how bad is it?A college professor and her students have challenged the
prevailing wisdom of the so-called 5-second rule, which for generations has
governed how long little morsels can remain on floors uncontaminated.
The window, the Connecticut team has concluded, is really 30 seconds.
"The students wanted two different types of food sources: a wet source and
one that was a dry food source, to test any differences," [Anne Bernhard,
assistant professor of biology at Connecticut College in New London] said. "You
would think that a wet food source would be more likely to attract bacteria very
Each food item was dropped in triplicate for specific intervals that ranged
from 5 seconds to 5 minutes.
"We did this experiment in the main dining area, and about 2,000 students
traffic through that area," [student Nicole Moin] said Wednesday. "So you'd
think there would be a multitude of bacteria on the floor."
In the first set of tests, moist apple slices were dropped.
And what researchers saw after 5 seconds were pristine morsels. Not until
the 1-minute interval did they find bacteria developing on the apple slices. It
took 5 minutes for organisms to colonize a Skittle.
The conclusion, Bernhard said, is that instead of a 5-second rule for moist
foods that have fallen, the standard should be 30 seconds: As long as you eat a
moist food within 30 seconds of its fall, you're very likely to be in a zone of
For dry, less porous foods, she added, you might be safe even if you allow
them to stay on the floor for 1 minute.
For the full story, go here.