Forensic analysis of post-blast residues from lead styphnate-based primers

Explosions involving primary explosives as the sole energetic material are very uncommon, since such compounds are typically used only to initiate main charges. This case report addresses an unusual blast at a civilian logistics facility, where primer compositions containing lead styphnate were present not as initiators but as the principal energetic charge. To investigate this rare scenario, postblast residues were collected from a cotton disc at the explosion epicenter and subjected to forensic chemical analyses. Tandem mass spectrometry (MS-MS) revealed the styphnate ion, while scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) identified lead-rich particles consistent with lead styphnate residues. Additionally, Pb-Ba-Sb-containing particles, characteristic of gunshot residue, were observed. The morphological characteristics of the particles indicate high-temperature formation and, together with their chemical composition containing Pb, Ba, and Sb, provide strong evidence of residues related to deflagration. These findings confirm that the explosion residues originated from a primary explosive, highlighting the forensic relevance of identifying such unconventional scenarios.