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Science of Handwashing: What Makes Handwashing Effective?

Science of Handwashing: What Makes Handwashing Effective?

As widely heard as it is now, we didn’t always recognize the science of handwashing. In this article, we’ll talk about the history of handwashing and the reasons why it’s the single, most cost-effective way to prevent infectious diseases.

A brief history of handwashing

According to the US Chemical, the first person to formally advocate handwashing was Moses ben Miamonides, a Jewish physician, philosopher, and astrologer from the 11th century. However, more centuries would pass, and the science of washing our hands remained unappreciated.

In 1847, Ignaz Semmelweis, a doctor from a hospital in Vienna, observed that his maternity patients were dying at a very alarming rate. The problem was so direly serious that mothers begged to be sent home to “safely” give birth in their houses.

After all, the mortality rate for mothers who delivered their babies at home was only 3% compared to the hospital’s death rate of 22%.

science of handwashing

Dr. Ignaz Semmelweis knew that he had to do something, so he began observing their maternity ward approach.

He soon realized that most of the mothers who died were cared for by student physicians who did autopsies early in the day. The problem was, after handling dead bodies, the students would go straight into attending to the mothers without cleaning their hands.

He then theorized that “cadaver particles” transferred from the dead bodies to the mothers. After instituting mandatory handwashing, the hospital’s maternity death rate dropped to 1.2%.

Even with Dr. Ignaz Semmelweis’ discovery, it would take more than a century for the science of handwashing and infection control to be fully recognized.

What exactly happens to our hands when we use soap and water to rub the germs away?

The science of handwashing

When we hold contaminated objects and surfaces, or sneeze and cough on our hands, we harbor germs into our skin. We can transmit these germs to ourselves (when we touch our face) or to others (when we touch them or they touched an object or surface we held).

To stop the spread of infection, experts recommend proper and regular handwashing. But, what makes handwashing so effective?

Use soap and water

Various studies have already proven that washing our hands with soap and water is more effective than cleaning it with water alone.

According to scientists, soap has surfactants, or substances that can break down the germs’ fatty envelopes. You see, for a microbe to stay active and cause an infection, they need an intact fatty layer; breaking it down renders them inactive.

Do we need to use antimicrobial soaps?

According to experts, ordinary soaps and detergents are enough to wash away the most common transmissible bacteria and viruses, but using antibacterial soaps effectively kills certain microorganisms.

Rub our hands together

The science of handwashing also involves friction.

Rubbing our hands together creates friction, which, together with soap, helps lift the germs and dirt away from the skin.

Remember: you need to rub your hands with soap and water for at least 20 seconds while covering all surface areas, especially the hard-to-reach places like under the nails. Do you worry about timing it correctly? No problem! Simply sing the Happy Birthday song twice while washing your hands.

Rinse under running water

Once you’ve rubbed all the surfaces of your hands, rinse the germs away under running water. Ensure that your hands are downwards so that the dirty water will not run down your elbows. Afterward, do not touch the tap.

You can use your elbow to turn the water off or cover the faucet with a tissue.

Finally, dry your hands with a clean towel or disposable tissues. Studies show that it’s easier for the germs to spread on wet hands than on dry hands.

Key Takeaways

According to experts, washing our hands is the single, most cost-effective way to prevent the spread of transmissible diseases like flu, pneumonia, and diarrhea.

But, to do it effectively, remember that the science of handwashing involves soap and water, rubbing the surfaces of the hands for at least 20 seconds, rinsing under running water, and drying the hands thoroughly.

Learn more about Healthy Habits here.

Hello Health Group does not provide medical advice, diagnosis or treatment.


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The Effect of Handwashing with Water or Soap on Bacterial Contamination of Hands
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Show Me the Science – How to Wash Your Hands
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Written by Lorraine Bunag, R.N. Updated May 26
Medically reviewed by Jobelle Ann Dela Cruz Bigalbal, M.D.