Hi, I have got a friend thats child is allergic to nikel and parfume. whats the best soap recipie i can make for her.
Thank you
A quick fling around google says that nickel can be used as a catalyst for hydrogenation, so don't use any artificially hard oils, margarines, or high melt point (modified) oils, if you are going to exclude nickel-rich ingredients.
After that, there are oils that naturally contain nickel.
Page 710 of this
journal (page 4 in the scan), gives a good list of nickel rich foods - looks like there's quite a few.
This blog seems to have information on oils that naturally contain nickel (which is helpful to use when you are avoiding them!)
https://nickelfoodallergy.com/natural-skin-products-loaded-with-nickel/
You haven't mentioned the age of the child. For a very young child, soap probably isn't recommended at all. For a young to teenage child, I would still err on the side of caution and use certified organic or source it from a farmer directly if you can, and if it must be soap, a mild castile as lsg described.
The effect I've seen in people with a strong nickel sensitivity is that the response is as if the soap itself is harsh - mostly it shows up as peeling, or contact dermatitis (but each person is different and a child needs additional caution). I don't know that a mild nickel sensitivity would show this (and I haven't checked whether the reaction is cumulative).
As an example, where I am, there is an imported KOH that causes this reaction (more than any source of NaOH I've encountered) - I like the idea of checking levels directly with the supplier.
Take care