This invention relates to a dual safety time delayed fuze, useful, for example, in conventional grenades, and particularly to a biased barrier between the pyrotechnic delay charge and the fuze ignitor charge. The barrier contains a flash-hole which is normally held out of alignment with the fuze powder train by a barrier latch. Upon ignition of the delayed charge, a heat motor, activated by the burning of the charge, expands against the barrier latch, displacing it, thereby allowing the biasing element to drive the barrier flash-hole into alignment with the delay and the ignitor. The barrier flash-hole may optionally contain a lead charge to insure ignition of the fuze.