triggering explosive; initiating explosive; primary explosive
Technical term for an explosive used to detonate a larger charge; common in military, demolition, and pyrotechnic contexts.
Triggering explosives are used in detonators.
This initiating explosive is sensitive to impact.
雷管 is the detonator device that often contains 起爆薬; 起爆薬 is the chemical substance itself.
Compound of 起爆 (きばく, 'detonation') and 薬 (やく, 'chemical agent, drug'). The exact historical derivation is uncertain, but the term follows standard Sino-Japanese word formation patterns for technical vocabulary.