Infection Protection

The "Five-Second Rule" Reconsidered

June 10, 2007

Two microbiology students who researched the ´five-second rule´ were featured on ABC´s "Good Morning America" on Tuesday, June 12. To view the segment, visit:

Molly Goettsche and Nicole Moin, both cell and molecular biology majors and members of Connecticut College´s class of 2007, conducted their research in microbiology class with Anne Bernhard, assistant professor of biology at the College.

To test the ´rule,´ which stipulates that dropped food will be safe to eat if it stays on the floor for fewer than five seconds, Goettsche and Moin took samples of apple slices and Skittles candies to Harris dining hall and the Crozier-Williams snack bar and dropped the foods on the floors in both locations for various time intervals. They then swabbed the foods and tested for any rogue bacteria that might have attached.

The researchers found no bacteria were present on the foods that had remained on the floor for five, 10 or 30 seconds. The apple slices did pick up bacteria after one minute, however, and the Skittles showed a bacterial presence after remaining on the floor for five minutes.

The results prove, according Goettsche and Moin, that you can wait at least 30 seconds to pick up wet foods and more than a minute to pick up dry foods before they become contaminated with bacteria.

"The five-second rule should probably be renamed," Goettsche said. "You actually have a little more time."

For more information contact Amy Sullivan at 860-439-2526 or

Press release courtesy of Connecticut College

Important disclaimer: The information on is for educational purposes only and should not be considered to be medical advice. It is not meant to replace the advice of the physician who cares for your child. All medical advice and information should be considered to be incomplete without a physical exam, which is not possible without a visit to your doctor.

Top 4 ways to prevent the spread of disease:

  1. Wash your hands often.

  2. Get immunized.

  3. Practice standard precautions.

  4. Disinfect regularly.