Peracetic acid (PAA) is a widely used green antimicrobial agent of the environmental protection chemicals, whose registered applications have expanded to include in sanitation at food processing and pasteurizers in beverage plants, agricultural premises, wineries and breweries, as well as the disinfection of medical supplies, to prevent biofilm formation in pulp industries, and as a water purifier and disinfectant. The thermal reactivity and hazard characteristics were evaluated for PAA solutions by calorimetry analysis methodology, where the thermal reaction and kinetic data were programmed by differential scanning calorimetry. The thermal stability screening test was able to determine the self-decomposition of PAA solutions, and to observe the initial exothermic temperature ( T i ) and heat of decomposition (Δ H d ). The thermokinetic parameters of PAA were also calculated according to the experimental data by temperature programming and thermal analysis model with Arrhenius equation. The purpose of this study was to elucidate the self-heating exothermic excursions associated with the various PAA solutions via C++ programming language. Understanding the thermal decomposition hazard of PAA was beneficial to proactive safety protocol for the industrial process, storage, as well as transportation.