I very much doubt submarines operate that high
replyThe ISS runs at 3000-6000ppm CO2. over 7000 is dangerous
over 7000 is dangerous[citation needed]
replyI found 3-11k as regular levels, with no impairment known of. So acclimatization can happen?
>Having CO2 sensors is mostly useless
replyI got one because old apartment and bad ventilation. Was able to open a window when I felt the effect before, but now I can get an alert earlier. Since getting it I could consistently feel the effect at around 11100-1300.