Friday, March 20, 2020

Soap Kills the Coronavirus

Viruses can be active outside the body for hours, even days. 

Disinfectants, liquids, wipes, gels and creams containing alcohol are all useful at getting rid of them – but they are not quite as good as normal soap. 

The short story: because the virus is a self-assembled nanoparticle in which the weakest link is the lipid (fatty) bilayer. Soap dissolves the fat membrane and the virus falls apart like a house of cards and dies – or rather, we should say it becomes inactive as viruses aren’t really alive. 

Therefore, any plain old soap and water can be very effective in annihilating coronavirus:

Know that washing the virus off with water alone might work too but not that effective. 

Water is not good at competing with the strong, glue-like interactions between the skin and the virus. Meaning, water isn’t enough. 

Soapy water is totally different. Soap contains fat-like substances known as amphiphiles, some of which are structurally very similar to the lipids in the virus membrane. The soap molecules “compete” with the lipids in the virus membrane. This is more or less how soap also removes normal dirt from the skin. The soap not only loosens the “glue” between the virus and the skin but also the Velcro-like interactions that hold the proteins, lipids and RNA in the virus together.

Alcohol-based products, which pretty much includes all “disinfectant” products, contain a high-percentage alcohol solution (typically 60-80% ethanol) and kill viruses in a similar fashion. 

But soap is better because you only need a fairly small amount of soapy water, which, with rubbing, covers your entire hand easily. Whereas you need to literally soak the virus in ethanol for a brief moment, and wipes or rubbing a gel on the hands does not guarantee that you soak every corner of the skin on your hands effectively enough. 

So, soap is really the best, but do please use alcohol-based sanitiser when soap is not handy or practical.

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