that SO2 kills me
With an atmosphere of that pressure it doesn't matter if its entirely oxygen you still wouldn't be able to survive or even breath, it doesn't have to much, it has to little. And yeah the CO2 paired with the SO2 would be pretty toxic as well.I found this Oceania in Andromeda with more than enough oxygen (perhaps too much?) although I'm sure those CO2 levels are too toxic for humans.
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A 100% oxygen atmosphere with this pressure (0.153atm) is breathable for acclimatized individuals. It is the equivalent of being here (46000ft at 100% concentration) on the graphic on the first page. But your point about it being unbreathable at the given concentration (plus the SO2) is correct.