A fire extinguisher system that generally provides a passive ability to prevent at least some inadvertent discharge events. The fire extinguisher system having a passively activated (turned on) and deactivated (turned off) sliding safety interlock cross shaft structure. The system interlock operation is generally performed without an operator performing any new or additional tasks in addition to those tasks that are typically implemented during installation, repair, and/or maintenance tasks. The safety interlock shaft is generally shaped and positioned to prevent inadvertent discharge of fire extinguishing chemicals via propellant when the outlet does not have either of a discharge conduit (pipe, tubing, or the like) or the anti-recoil plug properly installed therein.