[darkpuma]

>The resultant 12% oxygen is 60% of normal atmospheric air.

To put that in perspective, that's like being sent to the top of Pikes Peak (4.3km / 14,000') in seconds. Pilots flying that high in unpressurized aircraft are required to have oxygen masks. Most people will develop altitude sickness when rapidly subjected to that.

When you consider the potential for stress or panic in this kind of scenario, hypoxia emerges as a very real threat even for the young and healthy.