Why you should wash your hands | campus.sg

In a simple experiment that’s since gone viral, a teacher from Idaho has imprinted in all of us the importance of washing our hands properly – by using a loaf of bread as an example.

Jaralee Metcalf, a behavioral specialist from Idaho Falls Elementary School, was tired of always being sick, so she showed the kids why they needed to wash their hands to kill germs.

To explain how bacteria spread, she asked several kids with various levels of hand cleanliness to touch 5 pieces of white bread that were taken from the same loaf, at the same time. The first piece was rubbed on all of the classroom laptops. The second one was a control piece which wasn’t touched. The third piece was touched using unwashed hands. The fourth piece was touched after the kids washed their hands with warm water & soap. The final piece was touched after they cleaned their hands with hand sanitiser.

Then, they put the bread in individual plastic bags to observe what would happen over the course of one month.

The results

Apart from the control piece, the only slice of bread that didn’t have the obvious bacteria was example #4 – the one that was touched by hands that were just washed with warm water & soap.

Interestingly, the fifth piece — the “hand sanitiser” slice — turned out to have a lot of bacteria too, reminding us that hand sanitiser can’t replace proper hand-washing with soap.