1,1-Di(t-butylperoxy)-3,3,5-trimethylcyclohexane (TMCH) 88 mass% and 1,1-di(tertial butyl peroxy)cyclohexane (CH) 70 mass% are widely used in the polymer industry. Both are peroxyketal peroxides. Mixing peroxides with incompatible materials could induce runaway reactions in an upset situation. This is study of how acetone affects the peroxide decomposition reaction. We used differential scanning calorimetry (DSC) to detect the decomposition reaction with various ratio of acetone mixed with both peroxides. Our results showed that the acetone change from low concentration to higher concentration had a diverse effect on the peroxide decomposition reactions. A lower concentration of the acetone indicated an accelerated effect for the mixture conditions. The decomposition rates of peroxides decreased gradually as the concentration of acetone increased. (C) 2011 Elsevier B.V. All rights reserved.