Sodium magnesium silicate is a preservative, I believe... but the castile soap is soap made with vegetable oil instead of tallow (animal fat), so it'd still be a no-no for strict CGers. Also the ingredients that say "saponified" are indicating soap. In fact, I'm pretty sure that saponified coconut, jojoba, and olive oils are considered castile soaps.
Also, castile soap has a high pH (around 9) , so it can make hair (which has a pH of around 5-6) dry. So that could be an issue.
Hope that helps!
modified CG since July 2004.
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