To prevent fire and explosion accident caused by acetohydroxamic acid (AHA), the adiabatic stability of AHA was investigated by an accelerating rate calorimeter (ARC) in this paper. Comparison of test results from ARC and differential scanning calorimetry (DSC) was carried out. The test results show that the initial exothermic temperature for AHA was 352.68 K, the maximum exothermic temperature was 465.82 K, maximum self-heating rate and the time to maximum self-heating rate were 8.748 K•min^－1 and 382.65 min respectively, and the maximum pressure produced by unit mass was 2.22 MPa•g^－1. The high thermal hazard and powerful explosion of AHA were demonstrated by the results of DSC and ARC. Finally, The kinetic parameters such as apparent activation energy and pre-exponential factor of the thermal decomposition of AHA were calculated by a rate constant method, and the temperature of no return (T_NR) and self accelerating reaction temperature (T_SART) of AHA with some specific package were predicted. The studies have revealed that AHA is sensitive to thermal effect, and the thermal decomposition is hazardous due to its serious pressure effect.

Key words: acetohydroxamic acid, accelerating rate calorimeter, thermal stability