Disteardimonium Hectorite is a modified clay compound in which some sodium cations of the clay (hectorite) have been replaced by stearyldimonium groups (which include carbon chains containing 18 carbons).
In cosmetics and personal care products, Disteardimonium Hectorite functions as a dispersing agent - nonsurfactant.
Disteardimonium Hectorite is in a class of substances called quaternary ammonium compounds.
Ingredients in this class all have a nitrogen atom bound to four alkyl groups.
The nitrogen atom in these compounds always has a positive charge.
The alkyl groups in Disteardimonium Hectorite are two stearyl groups (18 carbons each) and two methyl groups (1 carbon each).
The CIR Expert Panel reviewed the safety of Disteardimonium Hectorite with other quaternary ammonium hectorite compounds including dihydrogenated tallow benzylmonium hectorite, stearalkonium hectorite and quaternium-19 hectorite.
All of these compounds have high molecular weights and carry a positive charge; therefore, the CIR Expert Panel concluded that these compounds would not penetrate the skin.
At concentrations used in cosmetic products, Disteardimonium Hectorite and the related quaternary ammonium hectorite compounds were not dermal irritants or sensitizers.