This Science Experiment Shows Why It's So Important To Wash Your Hands

You HAVE to see the photos!
PHOTO: getty images

Cosmo girls, the flu season is upon us. Colds and cough can easily affect you, but you can help prevent them by making handwashing a habit. Experts say it is “more effective than any single vaccine,” and two educators from the United States want to emphasize its importance through a recent classroom experiment that has gone viral.

In a Facebook post last December 2019, behavior specialist Jaralee Metcalf shared the classroom experiment she and co-teacher Dayna Robertson conducted with their 17 special education students. It involved fresh bread and touching it with clean and unwashed hands to see what happens.

“We did a science project in class this last month as flu season was starting,” the teacher wrote in her post. “We took fresh bread and touched it. We did one slice untouched. One with unwashed hands. One with hand sanitizer. One with washed hands with warm water and soap. Then we decided to rub a piece on all our classroom Chromebooks.”

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Each slice that the kids touched were sealed in plastic bags and left to sit for three to four weeks. Metcalf then shared photos of what the bread looked like after that long period. The result? “So DISGUSTING!!!”

The slice that was rubbed on Chromebooks was almost completely black by the end of the experiment, while the one touched with dirty (unwashed) hands was also almost filled with mold.

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Meanwhile, the fresh, untouched bread and the slice that was touched with washed hands remained pristine by the end of the experiment. Surprisingly, the slice which was handled by little ones who used hand sanitizer also grew molds.

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While the photos would make anyone shudder, users in the comments section wondered how the fresh bread could last that long without growing molds. Metcalf attributed it to preservatives and the fact that it was sealed shut in a Ziploc bag.

“If the bread had been exposed to air and moisture, the experiment may have gone faster,” the 23-year-old teacher explains to “The [pieces of bread] that were very clearly exposed to different germs grew mold quicker. And ones touched by clean hands plus the soap and water ones were not exposed to the germs that cause the mold growth to quicken.”

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With their experiment, Metcalf and Robertson hope to spread awareness that viruses and illnesses can easily spread through dirty hands, but handwashing can help stop it in its tracks.

“I’ve missed five or six days of school already because of my illness or my son’s illness,” Metcalf shared in an interview with Today. “When kids don’t wash their hands, it takes a toll not just on us as teachers, but also on our families.”

“As somebody who is sick and tired of being sick and tired… Wash your hands! Remind your kids to wash their hands!” Metcalf said in her Facebook post.

Both teachers say the visual from the moldy bread has had a positive effect on their students. “The students all thought it was gross,” Robertson told Today. “They have really turned their handwashing around (since the experiment). They realized that sanitizer doesn’t cut it, and they’ve got to do soap and water.”

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For people who want to test out the experiment in their own homes, Metcalf shares that they got the idea from the C.S. Mott Children’s Hospital website. A similar experiment was also done by a pre-kindergarten teacher in the U.S. in 2014.

No time to wash your hands? Hand sanitizers can reduce sickness, but only if you choose the right formula. Click here to find out which ones are effective.

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