5 Second Rule Debunked

From the Boston Globe:
Thursday, May 17, 2007
5-second dropped-food rule debunked

Good news for sloppy chowhounds - that food you dropped on the floor is still safe to eat 30 seconds later.

In the interest of culinary science, student researchers at Connecticut College conducted exacting experiments in the dining hall and the snack bar to see how long it takes for food dropped on the floor to attract rogue bacteria, the New London college said in a press release today.

According to lore and legend, dropped food that spends less than five seconds on the floor - the so-called five-second rule - is still safe to eat because rogue bacteria need more time to taint it.

The flip-side of the five-second rule, of course, is that consuming food that's logged more than five seconds of floor time should daunt even the most fearless of trenchermen.

But now student researchers Molly Goettsche and Nicole Moin claim their study debunks the five-second rule by showing that bacteria needs more time to contaminate dropped food than previously believed.

Working under the supervision of assistant professor Anne Bernhard, the two cell-and-molecular biology students experimented with samples of wet food (apple slices) and dry food (Skittles candy); food samples were left on the floor for various intervals, then analyzed for contamination, the college said.

According to Goettsche and Moin, the results of their research showed that people can wait as long as 30 seconds to pick up wet foods and even longer for dry foods.

Another potential finding perhaps: Either rogue bacteria don't particularly like Skittles or the candies are impervious to their immediate depredations; in the students' research, nearly five minutes elapsed before Skittles on the floor showed a bacterial presence.

In a statement, Goettsche said: "The five-second rule should probably be renamed. You actually have a little more time."
(By Chris Reidy, Globe staff)