By dissolving the fat membrane that holds it together.
Soap works extremely well against the Sars-CoV-2 (coronavirus) and most other viruses.
Viruses are self-assembled nanoparticles in which the weakest link is the lipid (fatty) bilayer. Soap dissolves the fat membrane that holds it all together and the virus literally falls apart like a house of cards and becomes inactive (as viruses aren’t really alive to begin with we can’t say they die).
Most viruses consist of three key building blocks: ribonucleic acid (RNA), proteins and lipids. Because there are no strong covalent bonds holding these units together you do not necessarily need harsh chemicals to split those units apart.
Washing the virus off with water alone might work. But water is not good at competing with the strong, glue-like interactions between the skin and the virus. Water isn’t enough.
Soapy water however 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.
Soap is better than sanitizers / disinfectants 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 as effectively as you would with soap.
While soap is the best option, please do use an alcohol-based sanitizer when soap is not available or practical.
Safety related coronavirus questions:
- How does soap kill the coronavirus?
- Do I need to wash my hands with warm water?
- Is using soap and water really better than disinfectants?
- Does hot water kill the coronavirus?
- Is drinking cold drinks during a coronavirus outbreak bad?
- Does washing clothes kill the coronavirus?
- How does alcohol kill the coronavirus?
- Does washing dishes in a dishwasher kill the coronavirus?
- Can coronavirus be transferred with cigarette smoke?
- What alcohol percentage (%) is required to kill the coronavirus?
- Can coronavirus be transferred with condensed breath (steam)?
Basic coronavirus related questions:
Similar questions: How does soap help prevent coronavirus infection?
