Abstract: Hazard suppression apparatus (10) is provided with a container (12) of suppression fluid and a non-explosive, pressurized gas-operated actuator assembly (16). The assembly (16) includes an actuator body (32) and first and second spaced apart rupture discs (36, 38) defining a zone (43) therebetween; the first disc (36) is preferably of bulged, scored configuration, whereas the second disc (38) is flat and has a series of vent openings (52) therethrough. A perforate, bar-type support (34) is positioned adjacent the second disc (38) and remote from the zone (43). A container (18) of high pressure actuating fluid is operatively coupled to the body (32) via a coupling unit (56) having an elongated, tubular nipple (58) equipped with a third rupture disc (62). A valve (70), adapted for connection with a hazard sensor is interposed between the container (18) and the coupling unit (56).