Have you ever wondered how some sunscreens feel lightweight yet provide powerful UV protection? The answer may lie in an ingredient called 2-phenylbenzimidazole-5-sulfonic acid (PBSA). Behind this complex chemical name lies a potent defender against sun damage. Let's explore how PBSA works in sun protection products.
2-phenylbenzimidazole-5-sulfonic acid (PBSA) is an organic compound widely used in sunscreens and personal care products for its exceptional UV-absorbing properties. This ingredient effectively absorbs both UVA and UVB rays, providing broad-spectrum protection. PBSA's remarkable photostability ensures lasting protection even under prolonged sun exposure, making it a crucial component in cosmetic formulations.
PBSA possesses several distinctive features that make it an ideal sunscreen ingredient:
- Water solubility: Easily dissolves in water-based formulations
- Photostability: Maintains effectiveness under sunlight
- Formulation flexibility: Compatible with various sunscreen and skincare ingredients
| Property | Description |
|---|---|
| Canonical SMILES | C1=CC=C(C=C1)C2=NC3=C(N2)C=C(C=C3)S(=O)(=O)O |
| InChI Key | UVCJGUGAGLDPAA-UHFFFAOYSA-N |
| Molecular Formula | C13H10N2O3S |
| IUPAC Name | 2-phenyl-3H-benzimidazole-5-sulfonic acid |
| CAS Number | 27503-81-7 |
PBSA's physical characteristics contribute to its practical applications:
- Melting point: Above 300°C (decomposes at 410°C)
- Appearance: White to off-white powder
- Solubility: Soluble in water
- UV extinction coefficient: 970 (E1%, 1cm at 302±2nm)
While PBSA is generally safe, proper handling is essential:
- May cause mild skin or eye irritation in sensitive individuals
- Dust inhalation might irritate respiratory passages
- Recommended precautions include wearing gloves and eye protection
To maintain PBSA's quality:
- Store in cool, dry conditions away from direct sunlight
- Keep containers tightly sealed to prevent moisture absorption
- Use appropriate personal protective equipment during handling
PBSA serves multiple purposes in personal care products:
- Primary UV filter in sunscreens
- Component in anti-aging formulations
- Ingredient in lightweight, non-greasy sun protection products
PBSA offers significant benefits for product development:
- Low skin irritation potential
- Suitable for sensitive skin types
- Contributes to non-oily textures
- Enables transparent water-based formulations
PBSA absorbs UVB radiation (280-320 nm) through excitation-deexcitation cycles, converting harmful UV energy into harmless heat. The sulfonic acid group enhances water solubility, making it particularly effective in aqueous sunscreen formulations.
PBSA has gained approval in multiple markets:
- Authorized in European Union countries
- Approved for use in Asian markets
- Maximum permitted concentrations vary by region
This versatile UV filter continues to play a vital role in modern sun protection, combining effective performance with formulation flexibility to meet diverse consumer needs.
