The decomposition of many hazardous materials goes through autocatalytic mechanisms. Due to the unpredictably sudden heat evolution companied with the decomposition of these materials, it is of great importance to identify autocatalytic decompositions and treat them with caution. In this work, a kinetic-parameters-free criterion is proposed to determine the autocatalytic decomposition using adi- 2 abatic calorimeters. This criterion states that the decompositions are autocatalytic if the values of RTP2/T-f-T-p obtained by adiabatic experiments in different conditions are variable; otherwise they follow n-order behavior. Mathematical simulations at different values of phi, alpha(0) and T(on )have been conducted for n-order and autocatalytic decompositions to validate the criterion. To further validate the criterion, this method is applied to four representative substances: DCP, 20 % DTBP in toluene, BO and CHP. Overall, the validity of this criterion has been verified by simulation and experiment results. (C) 2020 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers.