The viruses that hit the respiratory system, such as the new coronavirus, the flu and the common cold, can spread through our hands. If one is sick, he can touch some mucus with his hand and immediately viral droplets will stick to it.
From there viral droplets (such as the coronavirus) will remain in our hands and may enter our bodies if we put our hands on our faces.
That’s why our hands are at the forefront of the war against the coronavirus. The American Centers for Disease Control and Prevention (CDC) recommends washing your hands with soap and water as the best way to clean your hands. If soap and water is not available, a hand sanitizer with at least 60% alcohol can also help, says the CDC.
The CDC, therefore, prioritizes soap rather than unfair, as you will see below. This is because when you wash your hands with soap and water, you not only clean the viruses but eliminate them, making them harmless.
Soap is what chemists call “amphiphiles”. These are double-stranded molecules: One end of their molecule is attracted to water and repelled by fats and proteins. The other end of their molecule is attracted to fats and repelled by water. If you pay attention to the labels on soaps, the most common substance is “sodium laureth sulfate”. It is a detergent, which is often mixed with other chemicals to cleanse our hands without damaging our skin.
This dual nature chemical construction is what makes the soap so effective. When buying a conventional soap, be aware that it consists of a mixture of these amphiphiles.
Think about what happens when you pour some oil into the water. The oils float. This is because fats do not mix with water. But mix some soap in the oil and water and the oils will disperse. Basically, this is because the soap is attracted to the fat (from one end of the amphiphile), but then breaks down as it is drawn through the other end by water. In short: the soap first surrounds the oil particles and then removes them from each other.
The coronavirus looks a little like oils
Coronaviruses are a bit like the oil mentioned in the example above: they are essentially pieces of genetic information (encoded by RNA) that are surrounded by a coating of fat and protein. And this is the exact type of composition that soap can dissolve.
Coronavirus: How soap destroys viruses
One side of the soap molecule (the one that is attracted to fat and repelled by water) enters the envelope of the fat and proteins of the virus. Fortunately, the chemical bonds that hold the virus are not very strong, so this invasion is enough to break the virus coating. Then, harmless pieces of virus are rinsed with water.
And even if the soap does not destroy all viruses, you will push them out of your hands with any other dirt as you rinse. The soap will also remove other bacteria and viruses that may be a little tougher than coronaviruses and more difficult to decompose.
The secret is that it all takes a while for them to happen, so you should rub your hands with soap and water for at least 20 seconds.
In the following illustrated example, a greasy lotion is used initially, which resembles the way the coronavirus first attaches to the hands. Then, with the help of ultraviolet light, we see how the hands are gradually cleaned, first with pure water, then with soap and water for 5 “and 10” and finally, with only 20 “rubbing we achieve our goal:
First of all, your skin has stretch marks and it takes time for the soap to penetrate all the tiny folds and break down the viruses that are hidden inside. Then the soap takes a few seconds to do its chemical work.
And hand sanitizers?
Alcohol, the main ingredient in hand sanitizers, can also destroy viruses. Hand sanitizers work in a similar way, as the alcohol molecules are quite amphibious. The point is that a very high concentration of alcohol is required to achieve the same effect. Chemicals called quaternary ammonium compounds are the main constituent of disinfectant hands. These kill the viruses as well, but they can be a little harder on the skin. The CDC recommends hand sanitizers have at least 60% alcohol content.
In general, hand sanitizers are useful, but they may fail in ideal situations. If your hands are wet or sweaty when using the disinfectant, this can dilute it and reduce its effectiveness. Also, the disinfectant does not cleanse your hands of dirt to which viruses can also attach.
Coronavirus: Soap is our best weapon
The type of soap doesn’t matter. You do not need “antibacterial soap”. And you don’t need an over-hard detergent. The simple soap works perfectly.