A two-part starter mechanism for a powder aerosol generator fire suppression system is provided. Generally, the starter mechanism includes a pyrotechnic igniter assembly and a removable mechanical trigger coupled thereto. The igniter assembly is integrally formed with and/or embedded within the powder aerosol generator and operable, upon activation by the mechanical trigger, initiates a chemical reaction leading to the discharge of the powder aerosol fire suppressant. By being detachable, the mechanical trigger may be transported and stored separate from the pyrotechnic igniter thereby improving the overall safety of the fire suppression system.