Sulisobenzone on your skin: a safety profile

What is sulisobenzone?

The IUPAC name is 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid.

Also known as: 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, BP-4, benzophenone-4, 2-hydroxy-4-methoxy-5-sulfo-benzophenone.

IUPAC name

2-hydroxy-4-methoxybenzophenone-5-sulfonic acid

CAS number

4065-45-6

Molecular formula

C14H12O5S

Molecular weight

292.31 g/mol

SMILES

C1=CON=C1

PubChem CID

9254

Regulatory consensus

2 regulatory and scientific bodies have classified Sulisobenzone. The classifications differ — that's the data.

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter sulisobenzone

• sunscreen
• facial_sunscreen
• body_lotion
• color_cosmetics

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Sulisobenzone:

• Mineral UV filters (zinc oxide, titanium dioxide) — no systemic absorption
  Trade-offs: Alternative approach; specific tradeoffs depend on application context, scale, and regulatory requirements. Full hazard assessment of alternative recommended before adoption to avoid regrettable substitution.
  Relative cost: 1.2-2×
• Newer-generation organic filters with lower skin penetration (e.g., bisoctrizole)
  Trade-offs: Alternative approach; specific tradeoffs depend on application context, scale, and regulatory requirements. Full hazard assessment of alternative recommended before adoption to avoid regrettable substitution.
  Relative cost: 2-5× conventional
• UPF-rated clothing and physical sun protection
  Trade-offs: Removes 95-99% of dissolved contaminants including metals, PFAS, nitrates; wastes 2-4 gallons per gallon produced (improving with newer systems); removes beneficial minerals; $0.05-0.25/gallon; requires pre-treatment for longevity.
  Relative cost: 1.2-2×

Frequently asked questions