noun
detonator; primer; priming charge
Technical term for a substance or device that initiates an explosion. Used in military, mining, and demolition contexts.
爆弾には起爆剤が組み込まれている。
A detonator is built into the bomb.
起爆剤として雷管が使われる。
A blasting cap is used as a primer.
noun
Figurative use for something that sets off a major event, change, or reaction. Often used in social, political, or personal contexts.
その事件が戦争の起爆剤となった。
That incident became the trigger for the war.
彼の一言が改革の起爆剤になった。
His single remark sparked the reform.
触媒 is a chemical catalyst; 起爆剤 is more about initiating a sudden, often dramatic, change rather than facilitating a reaction.
Compound of 起爆 (きばく, 'detonation') + 剤 (ざい, 'agent, substance'). The figurative sense is a natural extension from the literal explosive initiator.