Originally Posted by frequentfloater (Post 9507579)

It depends on the cylinder manufacturer and local legislatory requirements - however I do recall there being a mandated minimum. It's got me thinking - will ask my friends still flying.

From memory, it was 100% in emergency situations, which was like only 4lt / min (it was 4 or 8 - but its been a while!)

I do remember the BA 767s we leased at QF had (I think) double the duration in the fixed cabin drop down masks, supposedly due to their frequent trips over high altitude areas.

To be honest, I always thought they were a health and safety hazard. The only time I used a bottle on myself (in an actual depressurisation event), we had to wrangle them in severe turbulence as the aircraft descended. They could be improved with something that secured them to an individual better.