Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
General Maintenance Action
Aircraft; Human Factors
For the past few weeks I have been flying with a new First Officer and we have been reviewing a variety of things to help gain knowledge on systems and procedures. While cruising at FL320 and reviewing the emergency descent procedure I pointed out the passenger O2 guarded switch and while flicking the front part of the plastic cover the Passenger Oxygen Caution message appeared. I immediately called the Flight Attendant and assured her that we didn't have any kind of pressurization problem and that I would make a PA announcement. I reassured to passengers via a PA announcement that the plane was perfectly fine and that the dropping of the masks was not related to a pressurization problem. I sent an ACARS message to Dispatch and another one to Maintenance describing the problem. I made another call to the Flight Attendant and she told me the passengers were fine; she had made another announcement reiterating what I had said. We continued to [our destination] where all the passengers deplaned without incident. Maintenance met the aircraft and secured the masks. I can't stress enough that the guard on the switch was never fully pulled up and the button never pressed in.The root cause was reviewing an emergency procedure and the main contributing factor was a very sensitive switch. Explicit communication with the entire pilot group that the switch is not to be touched; bumped [or] even grazed in flight.
CRJ-200 Captain reported inadvertently deploying the passenger O2 masks when he touched the guarded emergency oxygen switch cover.