Edited Version | Hyderabad | 30 Jun 2020
Following the outbreak of COVID-19 in several countries, various measures have been suggested to reduce the risk of infection. Cleaning one’s hands with an alcohol-based hand rub or washing them with soap and water is essential, as specified by WHO.
Why is this important?
So how does washing with soap help get rid of the coronavirus?
- There must be a high enough alcohol concentration to be effective .
- The entire surface of the hands and fingers must be covered .
- Skin irritation may occur. That's natural when rubbing something that is over 60% alcohol into your skin.
The virus tends to be viable for long hours on different surfaces that are regularly touched with hands. Therefore, frequent washing is important.
The grime on our hands contain innumerable viruses and bacteria. Washing hands without soap helps reduce the amount of microbes but does not remove most of the virus and bacteria completely. Therefore, using soap becomes far more effective in removing microbes.
Viruses have their genetic material encased in a layer of fat called the lipid envelop. Soap molecules are pin-shaped with a head that is water-loving and a tail that is oil-loving. Being oil-loving, the tail portion of the molecule tends to have an affinity for and ‘competes’ with lipids in the virus envelop.
Thus, soap and water together dissolve the viral bond and breaks the interaction between the virus and the skin surface Like soap, the alcohol present in hand sanitisers dissolves the lipid envelop, thus inactivating the virus.
But, sanitisers are not as effective as soap and water.
In order to be effective, sanitisers should contain at least 60% alcohol. Unlike soap lather, the alcohol does not come in contact with all parts of the hand. Sufficient use of sanitiser on the hand can increase the coverage.
“ Hand sanitizer should only be an option when you don't have access to a sink “
Hand sanitizers with an alcohol content that is greater than 62% can also destroy these lipid membranes, But they are ineffective against non-enveloped viruses, like norovirus and rhinovirus, which are variations of the common cold. Plus they provide none of the virus-destroying friction that rubbing your hands together and rinsing provides.
Hand sanitizer poses three challenges.
Soaps produce better results when hands are visibly dirty or greasy, unlike sanitisers.