I know that if there is too much CO2 in the air we will have too much greenhouse effect.

I would like to know if there is too much CO2 in the room, something like 3% while there is also more that adequate oxygen for us to breath. will we live or die? why?


2 Answers 2


CO2 forms carbonic acid in water, which helps to dissolve rocks and mountains in envitonmental science. It would slightly acidify your body with what is called a weak acid.

5% can cause acidosis and loss of conciousness, without lack of oxygen.

3% would devastate most chalk based sealife, corals and shells.

Perhaps lifelong breathing of 3% co2 would have serious effect on alkaline processes in the body, osteoporosis, and would have to be counterbalanced by the body to maintain its blood ph above 7.35, with alkaline chemicals like sodium.

Also check out this fact sheet.


First, the toxicity of any substance is a matter of dose. So the answer of your question is yes too much is toxic but the real question is how much is too much ?

This is still not clear in the litterature but effect are starting to appear over 3% see:

HAYWOOD C., BLOETE M.E. - Respiratory responses of healthy young women to carbon dioxide inhalation. Journal of Applied Physiology, 1969, 27, pp. 32-35.


ALEXANDER J.K.,WEST J.R.,WOOD J.A., RICHARD D.W. - Analysis of the res- piratory response to carbon dioxide inhalation in varying clinical states of hypercapnia, anoxia and acide-base derangement. Journal of Clinical Investigation, 1995, 34, pp. 511-532.

CO2 is the result of respiration as you know and a too high concentration in the blood result in a change a Ph of your blood and asphyxia. You can find more information on those effect here Permentier and al.

Hope this helps !

  • 1
    $\begingroup$ nice answer. You can add more information about physiological impact on hem, but it is still good :). $\endgroup$
    – L.Diago
    Commented Sep 11, 2018 at 4:46
  • $\begingroup$ I know CO2 is toxic if it's too much in the blood. by question can somehow be reduced to how doe increasing the CO2 level of air increases the CO2 level of blood. $\endgroup$ Commented Sep 11, 2018 at 9:38

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