The present work summerizes the results obtained during the slow cook off phenomenon to study the thermal stability of castable plastic bonded explosive (PBX-OXC-01). A method was developed to measure accurately the kinetic and physical parameters of this process and to establish an empirical model for cylinder blocks of castable plastic bonded explosive systems. The empirical model is based on the theoretical model of Zinn and Rogers which is valid for explosives only, and includes a limited number of experiments. It predicts the critical temperatures and induction periods of explosive blocks of any size.