Quaternium-90 montmorillonites (inci)

Quaternium (see also Polyquaternium) refers to complex quaternary ammonium compounds. Quaternary ammonium compounds, also called quats, have quaternary nitrogen atoms, i.e. all four hydrogen atoms of the ammonium ion (nitrogen atom) are replaced by organic residues. The compounds are therefore cationic, i.e. they have a positive charge. "montmorillonite" refers to a clay mineral; the mineral substance is the most essential component (60-80 %) of bentonite (montmorillonite is named after its first finding, the French municipality of Montmorillon).

Quaternium-90 montmorillonite is used in cosmetic formulations. The mixture acts as an emulsion stabilizer (supports emulsion formation and improves product stability) and as a viscosity regulator (increases or decreases the viscosity of cosmetic products).