Quaternium-18 Hectorite

Quaternium-18 Hectorite is an organoclay rheology modifier/suspending agent used at low levels (typically ~0.5–3%) to thicken and stabilize emulsions and makeup. As an insoluble clay treated with a quaternary ammonium compound, it is generally well tolerated in patch testing and real-world use, with irritation more likely from the overall formula (e.g., solvents, surfactants) than from the clay itself. Rare mechanical dryness or reactivity can occur in highly compromised eczema skin, but its intrinsic irritancy is low, supporting a very gentle score. Safety Notes: Quaternium-18 Hectorite is an organoclay rheology modifier/suspending agent used at very low levels (~0.05–0.3%) in leave-on creams/lotions and some rinse-off cleansers to stabilize oils, pigments, and insoluble actives. In high-oil, anhydrous or silicone-rich systems (e.g., foundations/primers, balm/ointment textures, certain hair styling and specialty skincare suspensions) commercial products and supplier formulating guidance commonly reach ~1–3%, with upper-end consumer-available thickened/suspension systems observed up to ~5% for maximum structure and anti-settling performance.