4-Hydroxybenzoic Acid
AKA “99-96-7, p-Hydroxybenzoic acid, p-Salicylic acid, 4-Carboxyphenol, Benzoic acid, 4-hydroxy-, p-hydroxy-, para-Hydroxybenzoic acid, p-Oxybenzoesaure, JG8Z55Y12H”
Acid
Ingredient Facts
4-hydroxybenzoic acid
AKA: 99-96-7, P-Hydroxybenzoic acid, P-Salicylic acid, 4-Carboxyphenol, 4-hydroxy-, P-hydroxy-, Para-Hydroxybenzoic acid, P-Oxybenzoesaure, JG8Z55Y12H
Acid · Preservative · EWG: 3
Synthetic
Preservative
Safety Concern
Acid
Not Clean
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
See origin →
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
Traditional Use
A naturally occurring compound found in various plants that was first synthesized in the 19th century. Developed as the parent compound for parabens, a class of preservatives introduced to cosmetics in the 1920s.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
EWG
3
CIR
Safe as used
Pregnancy
Yes
Restricted By
CIR Safety Findings
Not Phototoxic
ewg-3
medical-approval
all-shades-safe
Concentration Guide
8.0%
0%11%
Reg. Limit
EU regulatory limit: 8.0%. 0,4% (as acid) for single ester 0,8% (as acid) for mixtures of esters Source: EU Cosmetics Regulation (EC) 1223/2009, Annex V (Preservatives), Entry 12. Dermal absorption: 0.1%. Source: CIR Safety Assessment (CIR Seq 746).
Regulatory Agencies
Benzyl Alcohol, Benzoic Acid, Sodium Benzoate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Safety Assessment of Benzyl Alcohol, Benzoic Acid and its Salts, and Benzyl Benzoate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
4-Hydroxybenzoic acid rescues multisystemic disease and perinatal lethality in a mouse model of mitochondrial disease.
Corral-Sarasa J, Martínez-Gálvez JM, González-García P, Wendling O, Jiménez-Sánchez L et al.
Cell reports, 2024
4-Hydroxybenzoic Acid
European Commission
EU Cosmetic Ingredient Database (CosIng)
Benzoic acid and its derivatives as naturally occurring compounds in foods and as additives: Uses, exposure, and controversy.
Del Olmo A, Calzada J, Nuñez M
Critical reviews in food science and nutrition, 2017
Benzoic acid and its derivatives as naturally occurring compounds in foods and as additives: Uses, exposure, and controversy.
Del Olmo A, Calzada J, Nuñez M
Critical reviews in food science and nutrition, 2017
Benzoic acid and its derivatives as naturally occurring compounds in foods and as additives: Uses, exposure, and controversy.
Del Olmo A, Calzada J, Nuñez M
Critical reviews in food science and nutrition, 2017
4-Hydroxybenzoic Acid
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Benzoic Acid
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Toluidines, their isomers, salts and halogenated and sulfonated derivatives except 4-hydroxy-2-nitro-toluidine and hydroxyethyl-2-nitro-p-toluidine
Health Canada
Health Canada Cosmetic Ingredient Hotlist
Safety Assessment of Benzyl Alcohol, Benzoic Acid and its...
Wilbur Johnson, Wilma F Bergfeld, Donald V Belsito, Ronald A Hill, Curtis D Klaassen, Daniel C Liebler + 5 more
International journal of toxicology, 2017
Safety Assessment of Benzyl Alcohol, Benzoic Acid and its...
Wilbur Johnson, Wilma F Bergfeld, Donald V Belsito, Ronald A Hill, Curtis D Klaassen, Daniel C Liebler + 5 more
International journal of toxicology, 2017
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR