Initiators

(also called detonating powders or primary explosives), chemical compounds that explode easily on impact, friction, or flame, releasing energy sufficient to initiate detonation in secondary (high) explosives. The most important initiators are mercury fulminate, lead azide, lead trinitroresorcinate, and tetrazene. Azides and fulminates (salts of fulminic acid) of heavy metals, organic azides (such as cyanur triazide, C₃N₁₂), organic peroxides, derivatives of tetrazol and tetrazene, certain derivatives of diazo compounds, and silver acetylide are also used.

Initiators are used in war matériel and blasting operations to rig priming caps and electrical detonators. Mixtures of initiators with oxidants and combustible substances are used to rig percussion caps (they ignite powder charges of firearms); a mechanical mixture of powders of mercury fulminate, potassium chlorate, and antimony trisulfide is most often used for this purpose. Lead azide is mainly used to load commercial explosive devices (electrical detonators and priming caps). Because of the high sensitivity to mechanical and thermal impulses and the associated great danger of an explosion, the manufacture and handling of initiators must be accompanied by special safety precautions. The shipment of initiators is allowed only in the form of finished products (priming caps).