Handwashing Experiment: Glitter 'Germs' Show What Really Gets Hands Clean

We tell children to wash their hands, but telling doesn’t stick the way seeing does. A glitter experiment makes pretend germs visible, shows how fast they spread and lets students test what really works.

Part 1: how do germs spread?

You need clear hand gel or plain lotion mixed with fine glitter (these are your pretend “germs”), a desk lamp or sunny window and a class standing in a line.

Put a dab of glitter gel on the hand of the first person in line.
They shake hands with the next person, who shakes with the next, and so on down the line.
Everyone then checks their hands. Count how far the glitter travelled.

Glitter reached people far down the line, and nobody saw it happen. Real germs are too small to see, so we can’t tell where they are, which is why handwashing at the right times matters.

Part 2: a fair test of washing

Question: Which way of washing removes the most pretend germs?

Compare three methods:

Water only
Soap for 5 seconds
Soap for 20 seconds

You need: ordinary soap, basins of warm water and a jug if there’s no sink, paper towels and glitter gel.

Put the same amount of glitter gel on each volunteer’s hands.
Each volunteer washes using one method. Use the same amount of water and the same drying.
Check hands under the lamp and score by counting glitter specks left, or by estimating on a scale.
Repeat with different volunteers so the result doesn’t depend on one person’s hands.

Keep it fair: same amount of gel, same hands, same time for each method, same scorer.

What usually happens

Water alone removes some glitter, and soap removes much more. Twenty seconds of scrubbing, including thumbs, between fingers and under nails, usually leaves the least. Soap helps lift and carry away oils and dirt that things stick to. Scrubbing physically dislodges what’s left.

An honest note on the model

Glitter is not germs. It’s bigger and doesn’t behave the same way, and washing removes germs partly by loosening them and rinsing them away. The glitter is a model, an imperfect picture that helps us think about something we can’t see. Scientists use models all the time, and good ones come with a reminder of how they differ from the real thing.

When to wash

Before eating, after using the toilet, after coughing or sneezing into hands, after touching pets or garbage, and when hands look dirty.

Safety

Use fine, craft-grade glitter and don’t let students put hands in their mouths or eyes. Check for skin allergies and use fragrance-free soap if needed. Clean up glitter carefully, since it spreads.

Try Where do germs hide? from How Your Body Works, with a teacher guide and a student sheet. Sign up for three lessons free.