Sodium bicarbonate/baking soda irritation
I am new here but I really need help! I believe this forum might be the solution because here are many people knowledgeable in the chemistry behind the cosmetic.
This year I had an internship at a small company for natural cosmetics and my project was to find an alternative deodorant formulation without baking soda as some customers get rashes, itches etc (although it isn’t an allergen). Online I found that other companies use magnesium hydroxide as a deodorising agent instead of baking soda. As of now I do have some positive feedback from customers.
Now onto my problem: as I have to write a report on it, I was looking for resources (preferably papers, books, journals) about why baking soda causes these irritations on the skin. Of course the high/alkaline pH-value might be the reason but the deodorant with magnesium hydroxide is also alkaline. The only difference between these two is that baking soda is water soluble.
I would be grateful if someone could give me a good explanation why some people’s skin get irritated coming into contact with baking soda as well as a source supporting that explanation.