A lockout padlock for securing a switch of an industrial plant comprises a lock housing composed of plastic, a hoop, a lock cylinder that has a cylinder housing and a rotatable cylinder core, and a key, with the cylinder core being rotatable between a locked position in which the hoop is locked or lockable to the lock housing and an unlocked position. The lock cylinder has a plurality of tumblers, with each tumbler being movable between a respective release position and a respective blocking position. The plurality of tumblers comprise a plurality of pin tumblers that are spring-loaded in the direction of their respective blocking positions. The plurality of tumblers furthermore comprise a plurality of supplementary tumblers that are not spring-loaded and that are freely movably supported between their respective release positions and their respective blocking positions.