Science
Mechanism of Action
Benzophenone-9 functions by capturing UVA and UVB radiation (290–400 nm) through its conjugated molecular structure. Upon absorbing photons, the molecule enters an excited state and subsequently releases this energy as harmless heat as it returns to its ground state, thereby neutralizing potential photodamage before it can affect the product or the skin surface.
Research
Clinical Evidence
High confidence5%
Key findings
- 01 Concentrations between 0.1% and 1.0% effectively halt UV-driven color fading and fragrance spoilage in aqueous formulas.
- 02 At a 5% concentration, the ingredient demonstrates dual absorption peaks at 324 nm (UVA) and 286 nm (UVB).
- 03 Dermal testing at 10.72% confirmed the ingredient is non-irritating to skin tissue.
Transparency
Dusting Analysis
Benzophenone-9 is typically used at low concentrations for product stabilization; however, 'dusting' is rare because even at 0.1%, it serves a functional purpose in protecting the formula's aesthetics.
The Formula
Formulation
Stability
Highly stable in water-based systems, though pH levels exceeding 9.0 can trigger a bathochromic shift, reducing UVA protection efficiency.
Synergies
- Water-based antioxidants
- Chelating agents
- Aqueous colorants
Conflicts
- Highly alkaline environments (pH > 9)
- Strong oxidizing agents
- High-molecular-weight cationic polymers
Safety
Safety Profile
Reaffirmed as safe by the CIR Expert Panel in 2021. While not classified as a primary sunscreen active in the US, it is approved globally and permitted up to 10% in Japan.
Your Skin
Skin Compatibility
Our Assessment
Verdict
An essential stabilizer for water-based formulas that ensures product potency and aesthetic longevity against light-induced degradation.
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References
Sources