can we breath oxygen more than 21% or up to what level we can breath oxygen.?

Question

I heard If we breath more oxygen, co2 will reduce in our brain and we will be unconscious. our brain need CO2 in particular level.

Answer 1

Yes, humans can breathe 100% oxygen, but it increases the risk of hyperventilation. If the CO2 level in the blood gets too low, it confuses our regulatory mechanism.

Answer 2

In hospitals where people are having trouble breathing, they are given oxygen in higher percentages. It is flammable so there are always signs saying no open flames. The amount of CO2 in the blood is monitored in the brain and it causes us to breath deeper if we need more oxygen. CO2 will not reduce in your brain. You do become unconscious when there is not enough O2 or too much CO, carbon monoxide.

Answer 3

I guess not.
Level of CO2 in our body depends on how we extract energy from food and how it is expired by our lungs.
Similarly, the amount of oxygen intake depends on our body requirements and lung capacity to absorb it ( cases of lung disease).
On the other hand more intake of oxygen means more oxidation to produce CO2.