Science
Mechanism of Action
On the skin, CI 77891 primarily functions by physically reflecting and scattering both UVA and UVB rays, establishing a protective barrier against sun damage and premature aging. Simultaneously, it acts as an opacifying agent and white pigment, enhancing product uniformity and color, and can offer a skin-lightening effect. It also exhibits antibacterial properties in certain formulations.
Research
Clinical Evidence
High confidenceN/A
Key findings
- 01 The Scientific Committee on Consumer Safety (SCCS) has confirmed CI 77891 (including nano-TiO2) is safe for topical application as a UV filter in sunscreens at concentrations up to 25%.
- 02 SCCS also found it safe for use as a pigment in loose powder for face make-up applications up to 25%.
- 03 It is effectively incorporated as a UV filter in sunscreens, BB creams, and foundations within a concentration range of 2-25% for sun protection.
- 04 As a white pigment, it is safely used in lipsticks, powders, and concealers, typically ranging from 5-15%.
Transparency
Dusting Analysis
Due to potential respiratory concerns, the SCCS advises against the use of CI 77891 in applications leading to inhalation exposure, such as aerosol sprays or fine loose powders. For specific aerosol hair styling products, strict concentration limits apply: up to 1.4% for general consumers and 1.1% for professional hairdressers. This is due to concerns about potential lung inflammation and its classification as a suspected human carcinogen (Category 2) by inhalation. Therefore, any formulation intended for inhalation exposure should be carefully evaluated, with concentrations exceeding these limits considered a red flag in such contexts.
The Formula
Formulation
Stability
CI 77891 demonstrates excellent chemical, thermal, and photostability. However, its dispersion stability within formulations can be influenced by pH, with aggregation potentially promoted around an isoelectric point of approximately pH 5.8. Surface modifications, utilizing materials like alumina, fatty acids, or silicones, are frequently applied to enhance its dispersion, reduce dusting, and improve overall formulation stability.
Conflicts
- Formulations with potential for inhalation exposure (e.g., aerosol sprays, loose powders) should be avoided or adhere to strict regulatory limits due to respiratory safety concerns.
- Higher concentrations or non-micronized forms may result in an undesirable white cast on the skin.
Safety
Safety Profile
The Cosmetic Ingredient Review (CIR) and the U.S. Food and Drug Administration (FDA) classify Titanium Dioxide as a safe color additive and sunscreen ingredient for cosmetic use when meeting specified criteria. The SCCS confirms its safety for topical application in sunscreens up to 25%. However, for products with inhalation potential (e.g., aerosols, loose powders), significant safety concerns necessitate strict concentration limits (e.g., 1.4% for general consumers in hair sprays), due to potential lung inflammation and its classification as a suspected human carcinogen via inhalation.
Your Skin
Skin Compatibility
Our Assessment
Verdict
CI 77891 is an essential, highly stable ingredient valued in skincare for its effective broad-spectrum UV protection and its ability to provide opaque white pigmentation, demonstrating low topical irritancy and comedogenicity.
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References
Sources