NOVELTY - Method of using fuel cell-based system (10) involves communicating power to system controller (38) to control the fuel cell-based system; providing pressurized fuel flow to fuel cell stack (12) in the fuel cell-based system; detecting fuel flow pressure provided to the fuel cell stack; activating pressure switch (34) to interrupt the communication of power to the system controller; and releasing portion of pressurized fuel flow provided to the fuel cell stack in response to the fuel flow pressure provided to the fuel cell stack exceeding a second threshold.    USE - As method of using fuel cell-based system (claimed), preferably a pressure relief system for a pressurized gas e.g. hydrogen i.e. used as a fuel source in a fuel cell system.    ADVANTAGE - The fuel cell-based system prevents an overpressure condition from damaging the anode circuit of a fuel cell stack or creating a hazardous environment.    DETAILED DESCRIPTION - Method usable with a fuel cell-based system (10) involves communicating power to a system controller (38) to control the fuel cell-based system; providing a pressurized fuel flow to a fuel cell stack (12) in the fuel cell-based system; detecting a fuel flow pressure provided to the fuel cell stack; activating a pressure switch (34) to interrupt the communication of power to the system controller to isolate the fuel cell stack from the pressurized fuel flow in response to application of a fuel flow pressure to the pressure switch that exceeds a first threshold; and releasing a portion of the pressurized fuel flow provided to the fuel cell stack in response to the fuel flow pressure provided to the fuel cell stack exceeding a second threshold. The method further involves preventing startup of the fuel cell-based system in response to the release of the portion of the pressurized fuel flow; detecting the released portion of the pressurized fuel flow in the vent path; isolating the fuel cell stack from the pressurized fuel flow provided to the fuel cell stack in response to the detection of the released portion of the pressurized fuel flow in the vent path; and preventing startup of the fuel cell-based in response to a detected amount of fuel flow in the vent path exceeding a threshold amount.    DESCRIPTION OF DRAWING(S) - The figure shows a block diagram of a fuel cell-based system.    Fuel cell-based system (10)    Fuel cell stack (12)    Cathode inlet (16)    Pressure switch (34)    System controller (38)