Why it is preferable to use a hypoallergenic cleansing bar ( or soap-free soap or syndet)?
Skins have a natural acidity level (pH) of 5.The latter has to be maintained if the epidermis is to preserve its natural defences. A classical soap will release sodium on contact with water, which will aggress the skin and destroy its protective barrier ( the naturally protecting hydrolipidic film). The cutaneous pH will suffer a disequilibrium and the skin will be subject to dermatosis, itching, sensations of dryness…
The hypoallergenic cleansing bar is a gentle cleanser which respects the skin pH. It is specifically recommended for sensitive, reactive, dry, babies’skins or simply for anyone willing to respect their skin.
A short and slightly more technical account:
The manufacturing of the cleansing soap follows two stages: 1. A purely chemical stage: the saponification reaction. 2. A physical stage: the separation of several components of the reaction.
The saponification reaction is a reversible reaction. That is to say, in contact with water, the combined soda gets partly released, producing an alkaline pH close to 10.3/10.5. On an acid skin (pH =5) , these alkaline solutions destabilize skin ecology and may lead to itching on sensitive epidermis.
In order to make up for this drawback, a substitute has been created: the syndet or hypoallergenic cleansing soap. It contains surfactant cleansing agents. Stable in aqueous medium, the syndet has an acid pH close to that of the skin. It thus respects its balance, leaving a super fatted film and it is easily washed off even in the presence of hard water. That’s why it is highly advisable for sensitive skins and can be associated to dermatologic treatments since it respects the skin pH.
However, some anionic surfactants are more aggressive than others. Skin tolerance being our main target, we have chosen to discard them from our formula.