Thermal hazard evaluation of sodium dichloroisocyanurate via TG-MS, DSC, and ARC

Sodium dichloroisocyanurate (NaDCC) is a novel and effective material for sterilization, disinfection, and bleaching. However, the utilization of NaDCC has caused several thermal runaway incidents worldwide, raising attention to exploring its unknown thermal hazards. This paper simulated the different incident conditions to conduct a comparative study on the thermal stability and decomposition of NaDCC using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and accelerating rate calorimeter (ARC). The gaseous products of the thermal decomposition of NaDCC were analyzed by a thermogravimetry-mass spectrometer (TG-MS). Several kinetic methods were used to calculate Ea of the pyrolysis reaction of NaDCC under different conditions. TMRad and self-accelerating decomposition temperature (SADT) were calculated based on the thermodynamic and kinetic analysis. The results of TMRad showed that the adiabatic induction period decreased significantly, and the risk of losing control enlarged with increasing temperatures. Meanwhile, by comparing the SADT of NaDCC under several common packaging materials, the chemical plastic drums should be used for packaging materials of NaDCC. The result clarifies the reason for incidents and provides the fundamentals and valuable data for safe preparation, production, transportation, and storage of NaDCC.