Gross: Science class uses bread to conduct hand hygiene experiment

Elementary school students in Idaho received a lesson on the importance of hand washing after a teacher led a hand hygiene experiment involving bread.

Teacher Jaralee Annice Metcalf took five slices of white bread. One slice remained untouched. One slice was touched by students with unwashed hands. One slice was touched by students who had washed their hands with soap and warm water. Another slice was touched by students who had used hand sanitizer. The last slice was rubbed across the students’ Chromebooks that they use in class. Each slice was then placed into a freezer Ziploc bag.

The results took three to four weeks to manifest (due to preservatives, Metcalf says on her Facebook page.) The untouched slice and the slice touched by students who had washed their hands fared well. The slice touched by those who used hand sanitizer had one side which had grown a ring of mold on one side. The slice touched by students with dirty hands was covered in a layer of mold over most of its surface. The slice of bread that came in contact with the Chromebooks suffered the worst fate of all, turning a stomach-churning blue over almost all of its surface.

The teacher explained on her Facebook post that the laptop computers are sanitized on a regular basis, but not before the experiment.

Metcalf’s recommendation after conducting the experiment was, “Wash your hands!”

While WTSP points out that vaccines are the best way to avoid the flu, hand washing is an important daily function to ward off germs.

For those wanting to conduct a similar experiment at home, Metcalf recommended visiting this page on CS Mott Children's Hospital's website.

About the Author