Wait, GP said 800-1000, you have it at 1300-1400... isn't 1000 like the headache line? Shouldn't it be around 400-600 in a healthy environment?

Edit: Looking it up, the Wikipedia article on CO2 has the following to say on the topic:

> A study of humans exposed in 2.5 hour sessions demonstrated significant negative effects on cognitive abilities at concentrations as low as 0.1% (1000ppm) CO2

> Another study observed a decline in basic activity level and information usage at 1000 ppm, when compared to 500 ppm.

So 1ppk is definitely bad. Another datapoint is from 5ppk:

> At [5000 ppm for an 8h period, the] International Space Station crew experienced headaches, lethargy, mental slowness, emotional irritation, and sleep disruption.