Butylparaben
What it is
A long-chain alkyl ester of 4-hydroxybenzoic acid (CAS 94-26-8). Higher lipophilicity than methylparaben, increasing dermal penetration potential.
In this product: Antimicrobial preservative.
Dose & route, what actually matters
Eye-area leave-on (mascara). Periorbital skin. Butylparaben's higher lipophilicity increases dermal penetration vs. shorter-chain parabens.
EUROPEAN UNION
EU Cosmetics Regulation Annex V: maximum 0.14% (as acid) individually. Commission Regulation (EU) 1004/2014 established this limit citing precautionary principle related to endocrine disruption risk in infants and neonates; butylparaben is NOT allowed in leave-on products intended for the nappy area of children under 3.
UNITED STATES
No binding concentration limit. No infant product restriction. CIR and FDA self-assessment apply.
The evidence
Commission Regulation (EU) 1004/2014 established a 0.14% limit for butylparaben specifically, citing precautionary endocrine disruption concerns in infants and neonates. Butylparaben banned in nappy-area products for children under 3.
regulatory · 2014 · source
California Prop 65: Not listed.
How to avoid it
Paraben-free mascaras and eye products are widely available. Long-chain parabens (butyl, propyl) are the ones EU regulatory action specifically targeted.
Where it hides
Editorial analysis of publicly available regulatory and peer-reviewed sources. Not medical advice. We name our evidence and link it, including when an ingredient is fine.