A purified bentonite can meet pharmacopoeia limits
LaboratoryAlgerian bentonite, Na+ ion exchange and sedimentation
After purification, lead and arsenic stayed under pharmacopoeia limits and the germs tested for were absent (E. coli, Salmonella, S. aureus, P. aeruginosa). The authors judge it suitable for creams, powders and emulsions7.
Another bentonite, same conclusion after purification
LaboratoryRaw and purified Egyptian bentonite
The purified bentonite matches a reference montmorillonite (Wyoming type), with no detectable mineral impurities, a composition within pharmacopoeia limits and none of the pathogenic germs tested for8.
Clays: binding and releasing
Review2018 review
Clay particles can bind unwanted substances, but can also make toxic elements such as heavy metals available through skin or oral routes. Hence batch-by-batch control9.
Bentonite in a third of charcoal toothpastes
Review2017 review50 charcoal toothpastes sold online
A third contained bentonite. The review finds insufficient data on the safety and efficacy of these toothpastes10.