Science
Mechanism of Action
AZO forms a physical barrier on the skin, improving zinc oxide's semiconductor characteristics. This enables it to neutralize free radicals and bacteria through reactive oxygen species (ROS) generation or direct microbial cell wall contact.
Research
Clinical Evidence
High confidence0.2%
Key findings
- 01 Effective as a microbicidal agent against pathogens like E. coli and S. aureus at 0.001%-2.0%, particularly when synergized with other metal ions or surfactants.
- 02 Related zinc oxide formulations are non-irritating to guinea-pig skin. Aluminum-doped variants are used at 0.2-0.7% to enhance solubility and antimicrobial efficacy in film-forming compositions.
Transparency
Dusting Analysis
Safety data warns against inhalation due to potential sensitizing asthmagen risk, but no specific dusting thresholds are provided for cosmetic use.
The Formula
Formulation
Stability
Highly insoluble in its pure form, AZO disperses in both water and oil as a nanopowder. Its amphoteric nature means it is most stable in neutral to slightly alkaline environments (pH 7.0-11.0).
Synergies
- Other metal ion sources
- Specific surfactants
Conflicts
- Strong acids
- Strong alkalis
- Fatty acids (can form lumpy zinc soaps)
- Chlorinated rubber (risk of violent reaction)
Safety
Safety Profile
While not specifically reviewed by CIR as a complex, its components (Aluminum and Zinc Oxide) are well-documented. It is generally considered non-toxic for topical use, but inhalation should be avoided due to potential asthmagen risk.
Your Skin
Skin Compatibility
Our Assessment
Verdict
A versatile ingredient offering broad-spectrum UV protection, antimicrobial benefits, and skin protection with low irritation risk across all skin types.
Related
Similar Ingredients
Finding similar ingredients…
References
Sources