... 1018 Danger Class: 2.22. Physical Properties: Molecular Weight86.48Boiling Point, °C-40.82Relative Density(30°C), liquid, g/cm3 ... 1.177Melting Point, °C-160.00Critical Temperature, °C96.15Critical Pressure, MPA4. ... C)]0.16Critical density , g/cm30.526Vaporization heat below boiling point , KJ/Kg233.53. Quality Index (GB7373-87) GradeExcellent GradeFirst ...