Journal of Hazardous Materials B81 (2001) 67–82 Studies on energetic compounds Part 16. Chemistry and decomposition mechanisms of 5-nitro-2, 4-dihydro-3H-1,2,4-triazole-3-one (NTO) Gurdip Singh ∗ , Inder Pal Singh Kapoor, Sunil Kumar Tiwari, Prem S. Felix Chemistry Department, DDU Gorakhpur University, Gorakhpur 273009, India Received 29 July 1999; received in revised form 30 June 2000; accepted 3 July 2000 Abstract The present review deals with the chemistry and thermolysis of NTO and plausible decomposition pathways have been described. The decomposition of 5-nitro-2,4-dihydro-3H-1,2,4-triazole-3-one (NTO) induced by X-ray, UV, laser, photochemical irradiation has also been discussed. High-speed photographic studies of the impact responses of NTO are also included. The thermal decomposition of labelled NTO has also been described here. Methods of detection as well as safe disposal of NTO have also been mentioned. © 2001 Elsevier Science B.V. All rights reserved. Keywords: High energetic compounds; Thermolysis; Heterocyclic nitro compounds; Decomposition; Thermoanalytical techniques 1. Introduction The common explosives RDX (1,3,5-trinitro-1,3,5-triazacyclohexane), HMX (1,3,5,7- tetranitro-1,3,5,7-tetraazacyclooctane) and TNT (trinitro toluene) were considered adequate for all weapons applications uptill now. Due to the many catastrophic explo- sions resulting from unintentional initiation of either impact, friction or shock, aboard ships, ammunition trains and aircraft carriers, these explosives have become less attrac- tive. TATB (1,3,5-triamino-2,4,6-trinitro benzene) is noted for its insensitivity and is cur- rently employed as an IHE (insensitive high explosive) in few applications. Unfortunately, TATB does not have the energetic performance of either RDX or HMX. Therefore, there ∗ Corresponding author. Tel.: +91-551-200-745; fax: +91-551-340-459. E-mail address: mss2@nde.vsnl.net.in (G. Singh). 0304-3894/01/$ – see front matter © 2001 Elsevier Science B.V. All rights reserved. PII:S0304-3894(00)00289-2