>>9276614
No, there's loads of data on carbon monoxide poisoning. Also CO doesn't trigger a suffocation reflex.
Bear in mind normal ambient CO2 level is less than 1/20th of a percent of dry air, vs 78% nitrogen. So we're talking about more than 1600 times normal concentration as I understood the formulation of the original question. And it is absolutely not biologically neutral.
From NIH
>Carbon dioxide does not only cause asphyxiation by hypoxia but also acts as a toxicant. At high concentrations, it has been showed to cause unconsciousness almost instantaneously and respiratory arrest within 1 min [6].
>Carbon dioxide at low concentration has little, if any, toxicological effects. At higher concentrations (>5%), it causes the development of hypercapnia and respiratory acidosis. Severe acidosis increases the effects of parasympathetic nervous activity, possibly by interfering the hydrolysis of acetylcholine by acetylcholinesterase, resulting in a depression of the respiration and the circulation [6]. Concentrations of more than 10% carbon dioxide may cause convulsions, coma, and death [1, 15]. CO2 levels of more than 30% act rapidly leading to loss of consciousness in seconds. This would explain why victims of accidental intoxications often do not act to resolve the situation (open a door, etc.) [7, 10, 16].