Just found this plot in the Man-System Integration Standards (NASA-STD-3000 Volume 1) in section 5.1 http://msis.jsc.nasa.gov/sections/section05.htm#_5.1_ATMOSPHERE
I've seen that graph, as well... I have reason to believe that the lower bound is not really exactly accurate when you get to the right side of the graph (though is decently accurate on the left hand side) based on research that actually cites that graph.
bump.
I want a simple answer and I get.. graphs!
It looks from above like about 50% and 30% oxygen has no health issues and is safe re fire, so we would at least go that low if people were living and working in the moon?
How would this affect pre breathing time? Apparently a suit can be called zero-prebreathe if it works at 50% of earth pressure.. If we started at 50% could we step straight in a 25% earth pressure suit without pre breathing?
btw is there any number already chosen for a permanent moon base supposing we were to proceed? It seems to me the pressure it would work at would be one of the earliest things established before you started designing the thing.
