We’ve all been hearing “wash your hands” as the singular best way to stay healthy during these dark days of Coronavirus Covid-19.
It seems so basic— after all, it’s what we teach toddlers even before they are able to stand up on their own. Every parent has asked their child, even tweens and teens: “Did you wash your hands?” followed by a “Yes” and an eye roll, followed by “With soap?” followed by…. silence and said eye rolling and slouching child returning to the sink to wash with said soap.
Washing with soap and water is not a new phenomenon it didn’t just become a new hot latest and greatest practice weeks ago. It has been said that the ancient Babylonians invented soap around 2800 B.C.
However, the current health advice for washing hands with soap and water is based on the ability of soap molecules to interfere with lipids in the Covid-19 virus membrane, breaking down the outer fatty (lipid) layer of the virus. Moreover, the soap molecules can compete with the other non-covalent bonds between the proteins, RNA and lipids, effectively ‘dissolving’ the glue that holds the virus together. The soap can also disrupt the interactions between the virus and the skin surface, removing viruses from the skin.
What is it about soap that gives it such superpowers? (the science bit!)
Plain old hand soap, no, not antibacterial soap (remember, this is a virus we are dealing with, not a bacteria), contains molecules called ‘soap molecules.’
Each soap molecule has a hydrophilic (‘water-loving’) head and a hydrophobic (‘water-hating’) tail. Viruses are surrounded by a ‘lipid-bilayer’ made up of two bands of hydrophobic tails sandwiched between two rings of hydrophilic heads. When exposed to soap and water, viruses are prised apart, as the hydrophobic tails of the soap molecules attempt to escape from water and wedge themselves into the lipid envelopes of the virus rupturing the viral membrane. In effect breaking down the proteins to help prevent the virus from entering the cells on the skin.
Why soap and water is the ‘Gold Standard’ and NOT alcohol-based hand sanitizers?
There are two types of hand sanitizers alcohol-based and alcohol-free. Only sanitizers with a high concentration of alcohol (more than 60%) are effective against Covid-19.
Ethanol and other types of alcohol are solvents and are therefore more lipophilic
(‘fat-loving’) than water. This means that alcohol does dissolve the lipid membranes and disrupt the virus. These hand sanitizers are useful when soap and water are not available. Even so, soap and water will still remain the ‘gold standard’ as the virus detaches from the skin and falls apart readily in soapy water.
To sum it up!
- Clean hands protect against infection
- Protect yourself
- Clean your hands regularly.
- Wash your hands with soap and water, and dry them thoroughly.
- Use alcohol-based hand rub if you don’t have immediate access to soap and water.
- Repeat often.
- Tell a friend.
How do I wash my hands properly?
Washing your hands properly takes about as long as singing “Happy Birthday” twice, which is around 20 seconds and following the images below:
Courtesy of the World Health Organisation (WHO)