Explanation:
SOAP
It’s almost funny to think that as scientists over the world are hard at work on creating a vaccine against the new coronavirus, a bar of soap is enough to prevent an infection. In fact, washing with soap and water is still one of the best ways to prevent COVID-19.
This has to do with the chemical reaction that happens when soap molecules meet the new coronavirus. Soap molecules have two sides: one side attracts water and another side attracts fat. It so happens that all known coronaviruses, including SARS-CoV-2, are “enveloped” viruses. This means that they are all covered by an envelope of lipids (fat or grease) that have protein spikes sticking out.
The fatty envelope protects the genetic material inside the coronavirus. On the other hand, the spikes’ function is to attach to cells inside our body. Once attached, the spikes can unlock a cell’s membrane, allowing the genetic material to invade the cell. Once this invasion succeeds, a viral infection occurs.
Fortunately, when soap is mixed with water, this chemical reaction happens: the water-attractive side will bond with water molecules. However, the fat-attractive side will avoid water molecules--it will instead, latch on to any fat molecules present.
Say we start washing our hands with soap and water. If there happens to be a coronavirus on the skin of our hands, the soap molecule’s fat-attractive side will attach securely to the coronavirus envelope. Then when we rinse our hands, the water-attractive side will bond with the water that is sliding off our hands and into the sink’s drain.
What happens then? The coronavirus envelope literally gets ripped apart as the soap molecules bond with the water and are washed away. Once the coronavirus envelope is stripped away, the virus’ genetic material--already exposed and unprotected--will start to degrade. It is no longer able to infect us.
It takes time for this chemical process to happen, of course. Experts say a minimum of 20 seconds of handwashing is needed to complete this coronavirus-ripping chemical reaction. We take soap for granted but really, it’s a great bacteria and virus killer. So, keep on washing your hands regularly.
ALCOHOL
Rubbing alcohol sold commercially for household use is usually 60 to 70 percent solutions of either ethyl or isopropyl alcohol. Do not use alcohol solutions higher than 70 percent because these would tend to evaporate faster. Fast evaporation means the alcohol leaves your skin too quickly--not enough time to kill the germs.
Alcohol works similarly as soap in that it also has molecules that attract both water and fat. Like soap, alcohol can rip apart the protective envelope of coronaviruses.
Alcohol also has an additional mechanism that helps destroy bacteria and other microbes: it can dissolve or “denature” protein structures inside them. Destroying these protein structures also leads to the destruction of the microbe.
Take note: when using alcohol, use enough to wet your entire hands: palms, fingers, in-between fingers, and the backs of the hands. Just like soap, rub the alcohol for 20 seconds to allow the chemical reaction to work.
The advantage of using rubbing alcohol on our hands and other surfaces is that it can be used as is--unlike soap which needs water to activate its germ-killing power.
However, there is also a downside: alcohol does not work on all microorganisms. Furthermore, if there is a lot of dirt or grease on our hands, alcohol will not be effective at disinfection. The dirt and grease will simply absorb and block the alcohol, preventing it from killing germs.
So if there’s a lot of dirt and grease, especially visible dirt, on our hands, it’s always better to use soap and water. Alcohol is a close second in our preferred options to disinfect our hands.
