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Why handwashing with soap helps reduce the spread of Covid-19


We're all being told to wash our washing hands with soap to help reduce the risk of infection from the coronavirus. But how does it work and what makes it so effective?

Handwashing with soap

How germs are spread

Germs are essentially the umbrella word for nasty things that could make us ill. Germs can be found in the air, our bodies, on food, plants, animals, surfaces and just about anything we come into contact with.

When we touch a surface such as a doorknob or handrail, we pick up germs up with our hands. And if we then touch our face, which we often do, we pass on these germs from our hands to our mouth, nose and eyes. These are the key entry points through which germs sneak into our bodies.

How soap tackles germs

Sayandip Mukherjee, a Virologist and Senior Research Scientist at Unilever R&D Bangalore, explains: “Some germs have an outer protective covering made up of two layers of fatty molecules. Soap can help to break apart this outer protective layer, trapping and removing these germs along with any other oils and debris that are present in our hands. Now, for soap to do all this, remember we must wash our hands for at least 20 seconds.”

Studies by WHO have shown that by just washing our hands properly with soap and water we can cut down stomach-related illnesses by 50% and respiratory illnesses – such as the common cold and flu – by a third.

Soap and water rather than just using water

Washing your hands with water is a good way of removing dirt and is better than not washing them at all. However, the surfactants in soap can help to trap and remove germs in addition to better removal of dirt than washing your hands with water alone.

Surfactants are the cleansing ingredients that create foam and break down oil, grease and soil so they can be removed from skin.

Bar soaps, shower gel, shampoo and washing-up liquid can be just as effective as liquid soaps in removing dirt and germs and keeping your hands clean.

Feature image - Sayandip Mukherjee, Virologist
Remember, any soap – bar or liquid – if used properly, will help keep your hands clean and safe. Sayandip Mukherjee, Virologist

Your handwashing technique matters

The time you take and the technique you use to wash your hands are important. Follow hand hygiene practices frequently and as advised by your local government authorities.

If you use hand sanitiser, make sure it’s the right one

Washing with soap and water is a great choice for cleaning your hands and removing dirt and germs. However, if soap and water are not available, using an alcohol-based hand sanitiser is recommended by health authorities. But it’s important to use one that contains more than 60% alcohol. Not all hand sanitisers are the same.

What else you can do to help protect yourself against Covid-19

Scientists around the world are working on a vaccine that can prevent a coronavirus infection (such as Covid-19) in someone who has been exposed to it. But we’re not there yet. So, in the meantime, the most effective way of staying safe from the infection is to avoid being exposed to it entirely.

Based on the behaviour of respiratory viruses in general, the World Health Organization has outlined everyday actions that will help you steer clear of an infection, including:

  • Washing hands with soap and water or alcohol-based hand rub (>60% alcohol content)
  • Covering nose and mouth when coughing and sneezing with a tissue or flexed elbow
  • Avoiding close contact with anyone with cold or flu-like symptoms.
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