Cumene hydroperoxide (CHP) is normally produced by the cumene oxidation process. Severe fire and explosion incidents have occurred in oxidation and concentration processes due to the thermal instability of CHP. In this study, we used DSC and ARC thermal analysis techniques to measure the runaway thermokinetic data. Data such as adiabatic time to maximum rate (TMRad), adiabatic temperature rise (ΔTad), self-heating rate (dT/dt), thermal inertia (φ), etc., are used for runaway hazard evaluation. The thermal decomposition of CHP in cumene was found to be dependent on the CHP concentration which was characterized by the Accelerating Rate Calorimeter (ARC) test, isothermal and dynamic Differential Scanning Calorimeter (DSC) tests. The reaction order of 35 wt% CHP decomposition was determined to be 0.5. The Arrhenius parameters were measured to be Ea (kJ mol-1) = 120.6 ± 3.0 and lnA (min-1M1/2) = 30.2 ± 1.3. By using the thermokinetic data, plant vessel conditions, and the Semenov model, one can evaluate the criteria of critical vessel conditions, such as temperature of no return (TNR) and critical heat transfer parameter, (US/V)cr. Thermal hazards affected by CHP concentration were also discussed.