LabLearner Discussion: Hands Off!


Hands Off!

The final LabLearner Discussion in the COVID-19 Series involves the concept of hand washing and surface cleaning in preventing the spread of germs and disease. You and your child will discuss WHY soap kills germs like COVID-19 based on molecules and chemistry. Similar basic principles are also involved in the effectiveness of hand sanitizers and surface cleaners. Your child will actually do a simple at-home experiment to illustrate just how important soap and warm water are in killing COVID-19 and protecting their health.

Slide 1

This final LabLearner Discussion in the COVID-19 Series is devoted to the concept of hand washing and surface cleaning in preventing the spread of germs. Obviously, children should not be responsible for disinfecting potentially contaminated surfaces! The inclusion of surfaces in this Discussion is simply for your child to appreciate that germs may be and probably are on all surfaces.

Slide 2

This slide, and the next two, are repeated from the previous LabLearner Discussion, Say It, Don’t Spray It! We wish to reinforce the importance of the current situation, how many adults are involved in fighting COVID-19, and the idea (presented again in slide 4) that they can have an active part in in the battle against the virus by practicing prevention.

Slide 3

This is a good time to review that by paying attention and engaging in their own education that they are able to prepare themselves to do important jobs when they grow up.

Slide 4

Use this slide to remind and accentuate to your child that they are already in a position to help the doctors, nurses, and scientists who are currently fighting COVID-19. They can help! They can help prevent getting sick themselves and protect others from the virus as well.

Slide 5

This slide introduces the concept of thorough hand washing with soap and warm water as a means of stopping the spread of COVID-19 and staying healthy. In the following slide we will discuss WHY soap kills germs like COVID-19 based on molecules and chemistry.

To simplify, the reason soap works to kill germs is for the same reason that soap or detergents work so well in cleaning greasy dishes. Imagine trying to clean a butter dish with water alone. It would be exceedingly difficult because oil and water don’t readily mix. The water will just roll off the butter. Even rubbing will only transfer a little of the butter to your hand or rag. On the other hand, using soap and water gets the butter off the dish by helping to dissolve the butter in the water. 

Slide 6

Why is soap so effective at killing viruses like the new coronavirus COVID-19? This type of virus has a coating of lipids around it. In the illustration on this slide, the lipids are represented by the grey surface that the large red, and smaller orange and yellow proteins are attached or embedded. Notice that the individual lipid molecule in the membrane at the top right are very neatly organized with their “heads” pointing out and their “tails” pointing inwards.

Soap molecules are similar to lipid molecules in some ways.  When washing your hands with warm soapy water, the soap molecules break up the neat organization of the virus membrane and both the lipids and the proteins are solubilized – that is, the virus disintegrates into molecular bits and pieces. This kills the virus and rinsing your hands with warm water washes the dead virus down the drain. Good riddance!

Slide 7

A simple experiment that your child can do involves using Vaseline. Vaseline is a lipid and therefore doesn’t mix with water – it is not soluble in water. There are three simple steps to this experiment:

  1. Apply a dab of Vaseline to your child’s palm and have them rub their hands together to thoroughly coat them. Tell your child that, in this experiment, the Vaseline represents germs.
  2. Make sure the water from the faucet is only lukewarm and will not burn your child and have them rub their hands together under the flowing water to observe that the Vaseline (germs) is not removed.
  3. Have your child lather up their hands with soap and rub them together under the stream of lukewarm water. Have them add more soap if necessary and repeat until they see that the Vaseline (germs) was removed when they used soap.

Review the experiment with your child. Make sure they draw the conclusion that they need to use both soap and warm water to kill and remove germs from their hands. Most experts recommend washing one’s hands with warm, soapy water for at least 20 seconds. Depending on the amount of Vaseline used, it may take considerably longer to remove it all with the soap and water.

Finally, have your child thoroughly dry their hands after washing them and stress that this is also an important part of the hand-washing procedure.

Slide 8

This slide shows that hand sanitizers can also be effective in killing germs. When using hand sanitizers it is important to use enough that your child can rub their hands together for 20 seconds before it dries. Also, be sure they rub their hands together in such a manner that both the front and back of their hands are sanitized and that they cover past their wrists. Demonstrate this procedure to your child. Be sure you practice good hand washing and sanitizing habits yourself, your child will copy your behavior.

Slide 9

Since we have discussed touching objects and surfaces that might be contaminated with germs, you may point out to your child that this is why it is necessary to thoroughly wipe and clean surfaces with soap and water or a disinfectant.

If you wish, you can apply some Vaseline to a table or countertop and have your child try to remove it with just a rag and water versus soapy water and rag. The same principles apply as when we wash our hands with warm soapy water.

Slide 10

This slide emphasizes that it is science that will ultimately defeat COVID-19. It will also provide a time to reflect, in conversation with your child, all that they have learned about COVID-19. 

Slide 11

This final slide summarizes the most basic behavioral habits of disease prevention that we have discussed in this and previous LabLearner Discussions.

Hands Off!: Relevant LabLearner CELL Curriculum Units




Staying Safe

Discovering Life

Health and Hygiene


The Human Body

Microscopes & Magnification

Microscopic Explorations