Everyday Life & Technology
Why does soap help us wash our hands?
After gardening, Puschel and Flauschi discover soap’s helpful job.
The short answer
Soap helps loosen dirt, grease and many germs from hands. Rubbing spreads it over the skin; water rinses loosened material away. Soaping, thorough washing and rinsing work together.
An imagined Wusel scene
Puschel and Flauschi investigate
After planting, Puschel’s paws are covered in soil. At the garden washstand he wets them and adds soap. Flauschi waits beside him.
Puschel“A bubble! Am I finished already?”
Flauschi“For people, careful rubbing and rinsing matter. Just watching a bubble is not enough.”
Puschel rubs between his paw digits too. He has closed the tap while rubbing. Then he rinses away the soap and dries his paws.
Now Flauschi washes too. Puschel“Soap works with water and movement. My bubble only watched.”
Little Wusel quiz
What is missing if I only put foam on my hands?
Show answer
Thorough rubbing, rinsing and drying are also needed.
Are washed hands completely free of every germ?
Choose one answer: a), b).
- a)No
- b)Yes
Show answer
Correct answer: a): No No. Handwashing removes many germs and helps us pass fewer of them on. It does not remove all of them.
Word help
- molecule
- A small group of connected atoms, tiny building blocks of matter.
Explore in more detail
Here you will find longer explanations and further details. You can explore them together.
Understand step by step
How it works – simply explained
Water cannot remove everything
Greasy dirt clings to skin and mixes poorly with water. Germs may be present even on clean-looking hands.
Soap helps loosen it
Soap molecules interact with greasy dirt and with water. Rubbing with soap helps detach dirt and many germs.
Rinsing matters
Running water carries loosened material away. Lathering alone is not enough. Wash thoroughly, rinse and dry; soap does not make hands completely germ-free.
Why rinsing is part of washing
Imagine greasy dirt on a hand. Soap helps it mix with water and loosen from skin. Rubbing assists. Rinsing carries much of it away with water. Lathering is not the whole process. Soap removes many germs but does not make the hand completely germ-free.
The key points again
Discovery 1
Soap contains substances that help lift dirt, grease and many germs. Germs are so tiny that you cannot see them with your eyes alone. Some can make us ill. Soap helps lift them from the skin. Rinsing carries them away with water. Water alone is less effective.
Source: [1]
Discovery 2
Thorough rubbing matters, including the backs of the hands, between fingers and around nails. Lots of foam alone does not prove that hands are clean.
Discovery 3
The CDC, a US public health agency, recommends rubbing hands with soap for at least 20 seconds, then rinsing under clean running water and drying them. Handwashing can reduce the spread of germs, but does not make hands completely germ-free.
Source: [2]