In an explosives manufacturing plant, a detonator was tripped during a destructive test of the explosive trains (for cash-in-transit vehicles).

The detonator was tripped (it would seem) when connected to the detonator lead, between the time the technician deshunted the detonator and connected the detonator lead to the explosive train. This was the 12th and final control operation performed without fault detected during this activity and during this session. The activity had been conducted without incident since 1994. The detonating explosive train was mounted with a detonating cord and a low intensity detonator (with fusehead N20B).

The technician was seriously injured in the face, eyes and hands by the discharge and had to undergo surgery on one of his eyes to recover vision.

Setting off the detonator was caused by the static electricity from work clothes (especially the jacket), despite having been identified as a “conductor”, but for which the lining was not conductive.

Experts warned that wearing personal protective equipment (PPE), identified in the safety studies and prescribed by posted orders (goggles, gloves), was imperative and moreover the proper connection and testing of an initiation for small explosives must be designed to limit the impact of an accident on technicians. They stated that the risks from electrostatic electricity during initiation operations before detonation should not be underestimated.

A third-party expertise recommended the installation of a stainless steel firing table, to ensure its proper grounding (stainless steel braid) and provide a connection point for a conductive wrist strap. The design of the “firing box” will be improved, instructions and procedures completed and staff being warned. Finally, the operator will seek protective parkas that does not include insulating liners.