p-Hydroxybenzoic Acid (PHBA)


4-Hydroxybenzoic acid; para-Hydroxybenzoic acid; PHBA

Technical Data

CAS Number: 99-96-7
Molecular Formula: C7H6O3
Molecular Weight: 138.12
Beilstein Registry Number: 970950
EC Number: 202-804-9

FabriChem Specifications

AppearanceWhite powder
Assay99.8% Min.
Melting Point213°C Min.
Moisture0.20% Max.
Sulfated Ash0.02% Max.
Salicylic Acid0.1% Max.
4-Hydroxy Iso Phthalic Acid0.05% Max.
Potassium (K)10 ppm Max.
Sodium (Na)10 ppm Max.
Iron (Fe)10 ppm Max.

Molecular Structure



p-Hydroxybenzoic Acid (PHBA) [4-Hydroxybenzoic acid] is a monohydroxybenzoic acid, a phenolic derivative of benzoic acid. It is a white crystalline solid that is slightly soluble in water and chloroform but more soluble in polar organic solvents such as alcohols and acetone. p-Hydroxybenzoic Acid (PHBA) [4-Hydroxybenzoic acid] is primarily known as the basis for the preparation of its esters, known as parabens [a class of widely used preservatives in cosmetic and pharmaceutical products].