Synonyms: 4-Hydroxybenzoic acid;P-OXYBENZOIC ACID;para hydroxy benzoic acid;p-Hydroxybenzoic acid;4-Hydroxybenzoic acid (Paraben);HYDROXYBENZOIC ACID, 4-(P);HYDROXYBENZOIC ACID, 4-(RG);Methyl Paraben-13C6;p-Salicylic Acid;4-Carboxyphenol;4-Hydroxybenzoesaeure;4-hydroxy-benzoic acid;4-HYDROXYBENZOIC ACID FOR SYNTHESIS;ACETYLSALICYLIC ACID IMPURITY A (ASPIRIN IMPURITY A);Benzoic acid,4-hydroxy;Benzoic acid,p-hydroxy;HYDROXYBENZOIC ACID, P- POLYMER GRADE;PAR;para-Hydroxybenzoic acid;p-carboxyphenol;PROPYL PARAHYDROXYBENZOATE IMP. A (EP): 4-HYDROXYBENZOIC ACID, CRM STANDARD