4-Hydroxybenzoic Acid

4-Hydroxybenzoic Acid

AKA “p-Hydroxybenzoic acid, p-Salicylic acid, 4-Carboxyphenol, Benzoic acid, para-Hydroxybenzoic acid, p-Oxybenzoesaure”

Acid

Ingredient Facts

4-hydroxybenzoic acid

AKA: P-Hydroxybenzoic acid, P-Salicylic acid, 4-Carboxyphenol, Para-Hydroxybenzoic acid, P-Oxybenzoesaure

Acid · Antioxidant · EWG: 3

Synthetic

Antioxidant

Preservative

Anti-Aging

Safety Concern

Acid

Clean

A gentle preservative that keeps formulas fresh and effective by preventing bacterial and mold growth, ensuring your product stays safe to use from first application to last.

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.

Antimicrobial

Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.

Antioxidant

Fights free radicals — the unstable molecules from UV, pollution, and stress that break down collagen and cause premature aging.

Anti-Aging

Targets fine lines, wrinkles, or loss of firmness. Works by boosting collagen, speeding cell turnover, or both.

Brightening

Evens out dull skin tone for a more radiant, lit-from-within look

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

Melanin-Rich Skin

Suitable

Pregnancy & Breastfeeding Safe

Yes

EWG

CIR

Safe

Pregnancy

Yes

Restricted By

Whole Foods Premium Body Care

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).