Which type of soap should you choose to avoid damaging your hands?

Contrary to hydroalcoholic solution, soap allows us to rid ourselves of viruses and bacteria through a mechanical effect , rather than killing them. Indeed, soap is made up of long molecules, called surfactants, composed of a hydrophilic head that has a strong affinity with water and a hydrophobic tail that likes lipids (fatty substances). When washing hands with water and soap, the surfactant molecules attach themselves to the hydrolipidic film, a layer of fat that covers the epidermis, via the hydrophobic tail to avoid water and group together to form micelles. The dirt, dead cells, microbes and bacteria, present in the lipid layer, are then detached and eliminated during rinsing with water thanks to the hydrophilic part of the surfactants, attracted by the water molecules.

Furthermore, the surfactants contained in soap act on the envelope that surrounds viruses, which is formed of a lipid membrane also containing proteins and encapsulating the virus's genome. When soap is lathered, the tails of the soap molecules, which repel water, will attach to the lipid membrane of the viruses, causing their disorganisation. Indeed, the resultant forces exerted on the virus lead to the dismantling of the viral envelope. The virus is then broken down into different fragments that will become trapped in the micelles, before being washed away during rinsing. The virus is thus deprived of its ability to penetrate cells, thereby rendering it inactive.