Oxygen-consuming zero gap chlor-alkali cell was configured to minimize peroxide formation. The method is useful, for example, in the protection of integrated circuit manufacturing equipment, internal chamber components, and electrostatic chuck manufacture. The surface of a cavity defined in the plug is covered with an insulator film. If the suction fails, then a vent tube transmits the lost vacuum to an alarm chamber, thereby allowing a spring to bias the alarm button outbound, exposing the alarm ring to a worker so he can grab the workpiece and prevent damage.