An Emerging Safety Hazard: Triacetone Triperoxide Formation in Aged 2-Propanol

Abstract. Since the 1970s, and particularly during the first decade of the 2000s, the use of 2-propanol has increased substantially across society, including in healthcare, industry, academia, and laboratory environments. In parallel with this widespread use, there appears to be an increasing trend in reports of spontaneous formation of the high-explosive triacetone triperoxide (TATP) in aged 2-propanol. Several incidents worldwide have involved explosions during the handling of aged 2-propanol, some resulting in serious injuries. Previous studies have demonstrated that TATP can form naturally in 2-propanol upon prolonged exposure to air and that its physicochemical properties and friction sensitivity are comparable to those of laboratory-synthesized TATP, highlighting a significant and potentially growing hazard associated with storage and handling. In Norway alone, one accident attributed to TATP formation in 2-propanol was reported in 2024, followed by three additional incidents in 2025, suggesting an emerging and underrecognized safety issue. Here, we review the documented cases in Norway and further show that TATP is present in a substantial fraction of aged 2-propanol samples analysed in this study, indicating that spontaneous formation may be more prevalent than previously assumed and that the associated risk may be increasing.