Hi all
Just wondering if anyone can provide any research articles or personal insights into whether any ingredients should be avoided when a formula has clays (kaolin and/or bentonite - ie for a clay mask).
We've been testing some clay mask formulas, and a small portion of people have had a reaction (red and burning).
I'm wondering if the clays are having a reaction with the preservative ingredients used? We don't get any reports of red/flushing or burning sensation when using the same preservatives in formulas that do not have the clays included. We're using a preservative mixture of Sodium benzoate 0.15%, potassium sorbate 0.1%, sodium dehydroacetate 0.15%, phenoxyethanol 0.3%. Also have EDTA 0.15%, Citric acid 0.15% Which is also present in the formulas without the clay and do not get reports of red/flush or burning. So only seem to get some reports of skin sensitivity when the clay is added.
I cant find any research to suggest anything.
Any suggestions or articles much appreciated.
Kindest
Comments
It is mildly alkaline, that can exacerbate certain skin conditions, strip the acid mantle. It seems that your pH is fine at 5.
Did you measure it before or after mixing in the clay? Or immediately after mixing it in? If so I would let it sit and monitor the pH of samples at regular intervals over 24 hours, to see if there is any drift.
Does the redness happens with the same frequency if you used only Kaolin, or very fine french green clay (which is a montmorillonite of different origin)? Both are lesser irritants than Bentonite, with Kaolin being the more "delicate" one. (Nevertheless, clays are "brutal" ion exchange and absorbing agents, from a chemical point of view).
ı have good experiance on paint and coatings
do you ever test Laponite RD in your formulation