High concernPreservative
Butylparaben
ParabenEndocrine disruptorReproductive toxicant
What it is
The n-butyl ester of para-hydroxybenzoic acid. Among the most estrogenic parabens in common use due to its longer alkyl chain.
What it does
Preservative used in cosmetics, pharmaceuticals, and some foods to prevent microbial spoilage.
Why it’s a concern
Butylparaben showed the strongest binding affinity to estrogen receptors among the parabens tested by Routledge et al. in 1998 (Toxicology and Applied Pharmacology), roughly 10,000 times weaker than estradiol but present in far greater amounts in daily exposure. Animal studies link it to reduced sperm counts and altered testosterone. Denmark banned butyl- and propylparaben in products for children under three in 2011, a precaution later reflected in EU rules.
Also known as
butyl parabenbutyl 4-hydroxybenzoate
CAS numbers
94-26-8
Commonly found in
lotionsunscreenmakeupdeodorant
Safer alternatives
- phenoxyethanol
- sodium benzoate
- ethylhexylglycerin
Related chemical families
Sources
- Routledge et al. 1998
- Danish Statutory Order on Parabens 2011