Nano titanium dioxide is a physical/mineral UV filter used in sunscreens, where its reduced particle size minimizes the white cast while reflecting and scattering UVB and short UVA radiation. It is widely regarded as photostable and broadly tolerated on skin.
| Reported effect | How often | Notes |
|---|---|---|
| White cast or cosmetic residue | Common | Less pronounced than non-nano TiO2 but can still leave visible film, especially on darker skin tones. |
| Mild skin dryness or tightness | Uncommon | Often related to the overall sunscreen formulation rather than TiO2 alone. |
| Contact irritation or stinging | Rare | Generally low irritant potential; reactions more often linked to other formula components. |
| Allergic contact dermatitis | Very rare | TiO2 is considered a very weak sensitizer; documented allergy is exceptional. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.