A massive explosion in Taichung, Taiwan, in 2016, which was attributed to the thermal decomposition of o,o-dimethyl phosphoramidothioate, resulted in one fatality and one injury. This accidental explosion stemmed from certain elements being absent from process safety management (PSM), including process safety information, the management of change, process hazard analysis, mechanical integrity, operating procedures, training, and the pre-startup safety review. Problems encountered during the promotion of PSM were also identified, such as the hazards associated with highly hazardous chemicals at normal temperatures and pressure as outlined in the safety data sheet and the fact that these may be different from those under the conditions of the process. (c) 2017 American Institute of Chemical Engineers Process Process Saf Prog 37:104-109, 2018