Troubleshooting clay masks

[LBV]

I am making some skin care products and am testing a few clay masks and oils, but am surprised by the reaction that happened. I only made up small quantities and only did small spot tests, for which I am thankful.
I used samples of Kaolin, Ghassoul and Dead Sea Mud, singly and in combinations. On one side mixed with water and the other mixed with almond oil. Once washed off my mothers leg came up with a rash on the side with the clay and distilled water. The red strips were still visible and itchy the following evening. She only had a small rash with the kaolin and oil, but that disappeared that night.

Can anyone enlighten me as to why this reaction may have happened?

 

[Marsi]

how long was the clay sitting in water?

natural clays can contain bacteria and these can trigger a reaction
treat a moist natural clay product like food
(put it in the fridge if you are not using it immediately)

you can kill bacteria in natural clay by baking it in a moderate oven for 30 minutes
dont overcook it - it doesnt smell nice if you do

 

[LBV]

They went into the fridge as soon as they were made and they were tested the following day. I was aware that water increases the risk of bacteria, hence the fridge and I used bottled distilled water, which I added using a pipette. You could see the stripes where the clays had contact with her skin.