The suspected cause was a mixture of oxygen and hydrogen that passed downstream from the electrolysis unit into several storage vessels. Hydrogen-oxygen mixtures are very hazardous. Subsequent ignition resulted in internal pressure that exceeded the limits of the storage system. The design of electrolyzers, detection of upset conditions, and preventing the accumulation of oxygen within the hydrogen system is important for safe operation.

Detection systems are nearly always installed but the system design and installation details of detection equipment are up to the manufacturer. Standards are being developed for this market.