4-Hydroxybenzoic acid methyl ester, ROTICHROM® Working Standard, Molar mass (M) 152,15 g/mol, Density (D) 1,38 g/cm³, Boiling point (bp) 270 to 280 °C, CAS No. [99-76-3], UN-Nr. 3077, EG-Nr. 202-785-7, Empirical formula C8H8O3