This paper reports measurements made within the DIPPR(double dagger) Project 821 for the 1992 Project Year. Vapor pressures were measured to a pressure limit of 270 kPa or lower decomposition point for eight compounds using an inclined-piston and twin ebulliometric apparatus. Liquid-phase densities along the saturation line were measured for each compound over a range of temperature (ambient to a maximum of 548 K). A differential scanning calorimeter (dsc) was used to measure two-phase (liquid + vapor) heat capacities for each compound in the temperature region ambient to the critical temperature or lower decomposition point. Where possible, the critical temperature and critical density for each compound were determined experimentally. The results of the measurements were combined to derive a series of thermophysical properties including critical temperature, critical density, critical pressure, acentric factor, enthalpies of vaporization [restricted to within +/- 50 K of the temperature region of the experimentally determined vapor pressures], solubility parameter, and heat capacities along the saturation line. Wagner-type vapor-pressure equations were derived for each compound. In addition, the liquid-phase densities were compared with values derived using extended corresponding states. All measured and derived values were compared with those obtained in a search of the literature. Recommended critical parameters are listed for each of the compounds studied. The temperature at which initiation of thermal decomposition by a bond scission reaction occurs is discussed. A "Rule-Of-Thumb" is derived to estimate thermal decomposition temperatures by radical scission from a knowledge of the bond dissociation energy or vice versa. Compounds studied were acetophenone, (+/-)-1,2-butanediol, (+/-)-1,3-butanediol, diethylene glycol monopropyl ether, 1,3-dimethyladamantane, 2-ethoxyethyl acetate, ethyl octyl sulfide, and pentyl acetate.