Is breathing CO2 itself deadly, or does it has to do with the proportion of CO2 to oxygen, and other gases?

Is breathing CO2 itself deadly, or does it has to do with the proportion of CO2 to oxygen, and … by Vivienne Marcus Answer by Vivienne Marcus: Suppose you go swimming. You hold your breath and go u…

Source: Is breathing CO2 itself deadly, or does it has to do with the proportion of CO2 to oxygen, and other gases?