This volume is the 13b in the OECD Nuclear Energy Agency (NEA) Chemical Thermodynamics series. It is the second part of a critical review of the thermodynamic properties of iron, its solid compounds and aqueous complexes, initiated as part of the NEA Thermochemical Database Project Phase IV (TDB IV). This volume will be of particular interest to scientists carrying out performance assessments of deep geological disposal sites for radioactive waste. The results of this critical review carried out following the guidelines of the NEA TDB Project have been documented in the present volume, which contains tables of selected values for formation and reaction thermodynamic properties and an extensive bibliography.