Titanium Dioxide
Also known as: TiO₂, CI 77891
Description
Titanium dioxide is an inorganic (physical/mineral) UV filter and one of only two FDA Category I sunscreen actives classified as GRASE (Generally Recognized as Safe and Effective). It provides primary protection against UVB and short-wave UVA (UVA II) radiation, with diminishing efficacy in the long-wave UVA (UVA I) range. Micronized and nano-sized forms are commonly used to reduce the characteristic white cast while maintaining photoprotective efficacy. Titanium dioxide is photostable and does not degrade under UV exposure, making it a reliable broad-spectrum filter when combined with UVA boosters. Its inert nature and minimal irritation potential make it particularly well-suited for sensitive, rosacea-prone, and post-procedural skin.
Mechanism of Action
Titanium dioxide protects against UV radiation through a combination of scattering, reflection, and absorption of UV photons. In its rutile crystalline form, it absorbs UV radiation in the 290–350 nm range (UVB and UVA II), while also physically scattering photons away from the skin surface. Micronized particles (10–50 nm) shift the dominant mechanism toward absorption rather than scattering, improving cosmetic elegance. TiO₂ remains on the skin surface with negligible percutaneous penetration, resulting in a favorable safety profile. It does not interact with biological targets and has no known systemic pharmacological activity, making it one of the safest UV filters available.
Indications
- UVB and short-wave UVA protection
- Sensitive skin sun protection
- Rosacea-prone skin sun protection
- Post-procedural photoprotection
- Pediatric sun protection
- Pregnancy-safe sun protection
Available Concentrations
Side Effects
- White cast (especially at higher concentrations and on darker skin tones)
- Potential dryness with prolonged occlusive use
- Rare contact dermatitis or irritation
- Cosmetic inelegance in tinted formulations if poorly dispersed
Contraindications
- Known hypersensitivity to titanium dioxide (extremely rare)
- Inhalation risk with loose powder formulations (avoid aerosolized application)
Pregnancy Category
FDA Category I sunscreen active (safe — no systemic absorption)