Soap vs Sanitiser - Walthamstow Hall

Head of Physics, Mr Hill, has published the eagerly awaited results of one of the Wally Engineers’ final projects before lock down. Full findings can be found on Firefly but if you can’t wait to see the final results read on…

Wally Engineers is the Senior School’s STEM Club. They heard the Government advice on washing your hands, saw many people using hand sanitiser and decided to compare these different ways of keeping clean.

To make this more ‘real world’, they used bread as their base for bacterial growth and their own hands as a repository for bacteria.

4 Students rubbed their hands on untouched bread after each doing one of the following

  • Washing their hands with soap and water
  • Rubbed Hand Sanitiser into their hands
  • Rinsed their hands
  • Nothing

The bread was then left for 4 weeks and the results are below …

Two points to note…

No bacteria/virus/fungus was ever added to the lab/students

Whilst this does test how clean hands can be, it should be noted that mould is a fungus and cannot be exactly compared to a virus

28 Days in – 4 weeks after beginning – 08/04/20

  • ‘Water and Soap’ still remains entirely untouched by mould
  • ‘Rinsed Hands’ has developed some lovely colours for looking at, but not for eating!
  • ‘Hand Sanitiser’ has changed colour from green to brown
  • ‘Unwashed’ is becoming something not to have in the house and I have regularly checked the bag is very sealed
  • ‘Control’ has developed some mould. This one was only handled with a latex-gloved hand, interesting how this may not have been as clean as a very recently washed hand.

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