murphy4-Hydroxybenzoic Acid
AKA: 99-96-7, P-Hydroxybenzoic acid, P-Salicylic acid, 4-Carboxyphenol, Para-Hydroxybenzoic acid, P-Oxybenzoesaure
Synthetic
Preservative
Acid
Not Clean
Origin4-Hydroxybenzoic acid belongs to the benzoic acid chemical family and is produced synthetically from petroleum-derived precursors. It is synthesized through hydroxylation of benzoic acid or para-substituted benzene derivatives using oxidation processes.
The CIR Expert Panel concluded that the following 20 parabens are safe in cosmetics in the present practices of use and concentration described in the safety assessment when the sum of the combined concentration of parabens in any given formulation does not exceed 0.8 %...4-Hydroxybenzoic Acid...
Solubility Solubility (in 100 g of solution): 99% ethanol 38.75 g (67 °C); n-butanol 19.5 g (32.5 °C)
Formula
C7H6O3
Mol. Weight
138.12
CAS #
99-96-7
Form
Liquid
State
Pellets or Large Crystals; Dry Powder
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
Functions
Preservative
Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.
Antioxidant
Brightening
Anti-Inflammatory
Prevents microbial growth
Provides scent
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed1 review →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
3
CIR
Safe as used
Pregnancy
Yes
Restricted By
Concentration Guide
0%50%100%
Reg. limit 0.4%
CIR lists it as not reported to be in use.
CIR · report published 2020
EU regulatory limit: 0.4% (as acid) for a single ester, 0.8% (as acid) for mixtures of esters. Source: EU Cosmetics Regulation (EC) 1223/2009, Annex V (Preservatives), Entry 12.
Regulatory Agencies
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR