What hand-cleaning method is best? This fun hand washing science project brings to life the importance of handwashing for kids.
We took the science experiment for kids even further with our own hand washing science experiment!
If you love this gross science experiment, check out these other elementary science fair project ideas.
What is the Hand Washing Science Experiment?
In a bacteria hand washing experiment, kids are able to see just how many germs are accumulated on their hands after playing, even after they wash their hands!
Try this fun hand washing experiment to convince kids once and for all that they really do need to wash their hands with hot water and soap.
The handwashing experiment is a fun addition to classic science fair projects.
What you’ll need for the germs science fair project:
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What You Need for a Science Fair
You’ll want to have these supplies on hand before doing your science fair project. Shop the included Amazon storefronts to make things easier and don’t forget to download the free science fair planning checklist before getting started!
Science Fair Project Planning
When you’re planning your project, you want to keep everything organized. Click the image below to get my free science fair project checklist so you can start organizing your project from the start.
You may also want to check out this list of science fair project research supplies.
Supplies for a Science Fair Project
There are so many supplies for science fair projects that are individual to each project, but if you want a general list of possible supplies and inspiration for your project, check out my selection of science fair experiment supplies on Amazon.
Supplies for a Science Fair Presentation
Your science fair presentation is important! It should look presentable and eye-catching. Check out this list of my favorite science fair presentation supplies.
How Long Should You Wash Your Hands?
We didn’t test the length of handwashing sessions, rather, hand cleansing methods. But according to the CDC, the recommended time is between 20 and 40 seconds with soap and as hot of water as you can stand.
Bo kind of hates washing her hands, so I thought a hand washing experiment would be the perfect way to show her that hand washing is important.
How Clean Are Your Hands Science Fair Project Directions
In our experiment, we used six agar plates.
The goal of the experiment was to see which hand washing method was the most effective at stopping/slowing the spread of bacteria.
For each plate, I had Bo lick her fingers, then wash her hands in a certain way.
We used the following hand washing methods:
- No washing (control group)
- Washing with cold water
- Washing with hot water
- Washing with cold water and soap
- Washing with hot water and soap
- Using sanitizer
After washing and drying her hands, Bo touched her fingers to the surface of each agar plate. We labeled them with a duct tape strip and a permanent marker to keep track.
The agar plates went on top of the fridge, and we waited about a week.
Here is what they looked like before the bacteria grew:
And here is what they looked like a week later:
Washing Hands Science Experiment Results
Unsurprisingly (to me), the hot water and soap and the sanitizer plates remained the cleanest after a week. However, I was surprised to see that cold water and soap did so poorly at killing bacteria.
I really thought there would be a major difference between the soap plates and the non-soap plates, but there really wasn’t much at all!
That just goes to show that if you’re not washing your hands for long enough, then you aren’t actually cleaning your hands well enough.
Inform kids that they need to wash their hands for 2 happy birthday songs in warm water and scrub under nails and between fingers for a true clean.