We inhale Co2 with every breath! lol.
It is only harmful when it is so polentiful that it forms a HUGE cloud, displacing oxygen.
I remember hearing about a town in South America near a volcano. The volcano belched out a huge burst of Co2.
Being denser than air, the Co2 rolled down the volcano side and settled for a time right on this town, causing everyone to suffocate.
Scary, but you would have to be in a basement with 100 fermenters going full ferment to even be concerned.
.......BACK OT
I recently moved my 3 fermenters (after initial fermentation) into my bedroom.
(I currently have a female adding Co2, but I like to live DANGEROUSLY!!
)
I have to say that I really like hearing the occasional bubble. I feel like I have a slight finger on the pulse of each fermentation.
I may be fooling myself as some gas off while others are actually fermenting, but I like it anyways