B737 Next Generation Undifferentiated
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 214; Flight Crew Type 6068
Aircraft Equipment Problem Less Severe
Aircraft; Equipment / Tooling
I pulled the oxygen mask out to wear during bathroom breaks. I found that the beige/orange oxygen mask goggle portion did not seal up at the top of my face with very large gaps. It was written up in GUA.Yesterday; the First Officer pulled the oxygen mask to wear during bathroom break and found a plastic rivet missing on the front of mask. It was written up [at the destination airport]. On arrival I stepped off the aircraft to see a Mechanic on the jetway with a new beige/orange oxygen mask that I had previously known not to seal up around my face. I asked I thought we were taking these off the aircraft because they don't seal up and he said he didn't know but this one came from the parts room at the hangar. Maybe it's possible I do not understand the engineering of these new oxygen masks and air is expelled out these large gaps to prevent smoke from entering; or they fit perfectly on square faced person; or they are poorly designed masks. But I do think we need to take a closer look please.
B737 Captain reported an anomaly with the cockpit oxygen masks that did not seal properly.