Abstract: A system for detecting oxidizer burn through comprising a network of three ndependent photodetectors and their associated circuitry connected to a two-out-of-three majority voting network. When a fire occurs, the photodiodes will produce a response. If two or three signals are received by the voting network, an output signal is produced which can be used to dump oxidizer, activate alarms, close valves, activate damage control systems, etc. Two types of detection techniques are possible: (1) spectral line detection which incorporates an optical pass filter before each photodetector which limits the detector so that it responds only to a wavelength of light produced by a particular burning metal-oxidizer combination, and (2) intensity change detection which incorporates comparison circuitry after the photodetectors which compares detected light levels to ambient light levels.