Abstract The chemical decomposition of NTO 1 and its corresponding amine ATO 2 was investigated. To make easier the identification of the decomposition products, we synthesized 14 C-labelled NTO and ATO. Our results confirmed the high stability of the NTO triazolone ring. Its scission can be achieved partially by sulfuric acid under intensive heat and pressure. The triazolone ring of ATO was cleaved in alkaline solution. Carbon dioxide ...