How long would it take for death to occur from CO2 exposure and at how many ppm?

Question

My husbands has 3 20lb CO2 tanks in a small work area. The other day I caught our 13 year old son and his friends messing around with them. I was told if they were turned on fully the air would drain from the tanks in about 2 to 3 minutes. If all three tanks were on would there have been enough gas to have killed these young boys? And how quickly could it have happened if so?

I am asking this as my husband believes there is very little risk and I am not in favor of it. If an accidental release of the gas were to EVER happen while my husband or anyone else was in the garage I want to be assured that there is enough time to realize it and the effects would not be instantaneously.

Answer 1

CO2 is not poisonous, and you cannot die from CO2 poisoning, per se.

However, if you are in an atmosphere where enough CO2 is released, the CO2 will displace the oxygen from the air, and you can die of suffocation. This is somewhat obvious if you consider the case of a pure CO2 environement with no oxygen whatsoever.

Your body's respiration is triggered by CO2. When you try to hold your breath, you don't feel like you "have to breathe" because you're running out of oxygen. Instead, the breathing reflex is triggered by an excess of CO2 in the lungs.

I suppose if the boys managed to displace too much oxygen from the air, they'd find themselves short of breath, and want to get out of the room so that they could breathe.

Hopefully, that would happen before they passed out, which could be fatal if there is little ventilation in the room.