A packaging system includes a container (34) within which are disposed first detonator devices (10) having reactive coils (16), e.g., coils of shock tube leads, and second detonator devices (20) having inert coils (26), e.g., coils of insulated electric leg wires. The inert coils (26) are interposed between the reactive coils (16) and are approximately co-extensive with the reactive coils (16), so that the inert coils (26) form a barrier to propagation of an accidental initiation from one reactive coil (16) to another. Reactive coils (16) and inert coils (26) are fastened to each other to form mixed coil pairs (30) which are nested to interpose a pair of the inert coils (26) between at least some of the reactive coils (16). A method of packing the first and second detonator devices calls for placing them in a container (34) in the described arrangement.