Within a munitions plant, several detonations occurred successively during the incineration of packaging that used to contain electric detonators.

The packaging material came from a building where the detonators were being refurbished; these detonators contained 0.25 g of lead azide and 2 g of secondary explosive and were initially packaged into boxes of 30 inside individual cardboard tubes. The packing operation consisted of placing each detonator into a metal tube and then inside crates containing 25 such tubes. The empty cardboard tubes were stacked alongside the original packing boxes for subsequent destruction.

Several detonators in the cardboard tubes most likely stayed in a box that afterwards got stuffed with other empty cardboard tubes. Technicians working in the burning zone sampled a few packaging specimens to ensure they were empty before inserting them into the incinerator furnace.

The operator had informed technicians of the importance in verifying packaging contents and moreover implemented a systematic control of empty packaging within the shipping zone. The operating protocol was modified to include: breaking the cardboard tube after verifying that no contents remained inside, and the systematic folding of empty boxes into flat cardboard sheets. An element accounting sheet with the headings “incoming / outgoing / reject / return to warehouse” was also introduced.