A method and system for using an existing open-environment hydrogen sensor for detecting hydrogen leaking from an atmospheric reference port of a pressure regulator. The atmospheric reference port extension tube of one or more pressure regulators in a hydrogen storage system is routed past a hydrogen sensor which is already used to monitor air around the hydrogen storage system for the presence of hydrogen. In this configuration, the open-environment hydrogen sensor can quickly and reliably detect hydrogen gas flowing from the atmospheric reference port of one of the pressure regulators in the event a pressure regulator develops an internal leak.