Tin Oxide

Tin oxide is an inert inorganic pigment/opacifier used at low levels in color cosmetics (commonly a few percent) to add opacity and shimmer. It is generally non-reactive and not a common irritant or sensitizer in patch-testing, but as a particulate mineral it can cause occasional mechanical irritation in highly reactive or compromised skin (especially around the eyes), so it is best rated very gentle rather than fully inert. Safety Notes: Tin Oxide is most commonly used as a pearlescent/opacity modifier in color cosmetics and some skincare-makeup hybrids; at the low end it appears as a trace component (~0.01–0.1%) when supplied as part of mica/TiO2/SnO2 effect pigment blends in leave-on products. Higher levels occur in shimmer/highlighter products and radiant primers where SnO2 is used as a discrete effect pigment component, with total SnO2 commonly in the low single-digits and reaching the low-teens (~10–15%) in highly pearlescent consumer formulations. It is uncommon in rinse-off skincare and, where present, is typically at the low end due to limited benefit and cost/handling considerations.