Iron Oxides

Iron oxides are inert mineral pigments used primarily as colorants in makeup and tinted sunscreens, typically at low-to-moderate concentrations, and they are not chemically active on skin. Clinical experience and patch testing data generally show very low irritation and sensitization rates; reactions are uncommon and more often related to contamination, particle friction, or the overall formula rather than the pigment itself. Given their strong tolerability even in sensitive populations, they fit an exceptionally gentle irritancy profile. Safety Notes: In commercial cosmetics, iron oxides are used as pigments and can appear at trace levels (~0.01–0.1%) in lightly tinted skincare (tone-up lotions, subtle color-correcting serums) or as part of blended color systems. At the high end, consumer-available color cosmetics with strong coverage—particularly cream foundations, concealers, camouflage makeup, and some pressed/powder foundations—can reach ~15–25% total iron oxides (often combined with TiO2) depending on shade depth and opacity. Use is primarily leave-on; rinse-off products typically contain none or only trace carryover from colorant systems.