Ci 77891

CI 77891 is titanium dioxide, an inorganic pigment/UV filter used at variable but often meaningful levels in makeup and mineral sunscreens; it is insoluble and generally biologically inert on intact skin. Clinical experience and patch testing show low irritancy for most users, but in eczema-prone or highly reactive skin it can still cause mild irritation from particulate/friction effects or from contaminated/impure grades, so it is not scored as completely inert. Safety Notes: CI 77891 (titanium dioxide) appears at trace levels (~0.01–0.1%) as an opacifier/whitener in lotions, cleansers, and creams, including some rinse-off products where only minimal whitening is needed. In leave-on color cosmetics and hybrid skincare (tinted moisturizers, foundations, concealers, tone-up/brightening creams), it commonly rises into the several-percent range and can reach ~20–30% in highly pigmented, high-coverage consumer products. While TiO2 can also serve as a UV filter, the highest consumer-available levels are most consistently observed in pigmented makeup and tone-up products rather than standard facial sunscreens.