Detection of TATP in vapour phase: influence of the packaging: Influence of the packaging

The threat posed by improvised explosive devices (IEDs) remains significant, making early detection a security priority. Among available detection techniques, explosive detection dogs (EDD) are still considered one of the most effective tools for detecting explosives in the vapour phase. However, packaging materials can significantly influence the availability of explosive vapours thereby affecting their detection. This study investigates the diffusion behaviour of triacetone triperoxide (TATP), a common homemade explosive, through various packaging materials.TATP diffusion was analysed using Solid Phase Microextraction (SPME) and Getxent tubes. Experiments were conducted using up to four successive polyethylene (PE) bags. The results demonstrated that most of the TATP vapour diffuses through the bag's seal rather than through the polymer matrix itself. Furthermore, the quantity of TATP inside the packaging did not influence the diffusion rate, as the vapour concentration is governed byTATP'svapour pressure, which is independent of the sample mass.Diffusion through a plastic bottle was also evaluated and found to be slower than through PE bags. In contrast, no diffusion of TATP was detected through sealed aluminium-coated polymer bags, indicating a complete barrier effect.Detection tests with trained EDDs corroborated with the analytical results: dogs consistently detected TATP stored in PE bags and plastic bottles but failed to do so when the explosive was sealed in aluminium-coated bags. These findings confirm that packaging plays a crucial role in the detectability of explosives by EDD.