4-Hydroxybenzoic acid ethyl ester, ROTICHROM® HPLC, Molar mass (M) 166,18 g/mol, Density (D) 1,291 g/cm³, Boiling point (bp) 178 °C, CAS No. [120-47-8], EG-Nr. 204-399-4, Empirical formula C9H10O3