Hi All,
I am posting this due to a discussion among scuba friends. The topic was whether it was possible or not, in an emergency situation and without any other source of air use the air which can be found in the BCD more than one time: that is inspire the air, expire back in the BCD and repeat the sequence.
Aside from any health consideration about the germs that can be there, the basic issue was the max level of Carbon Dioxide which can be tolerated and for how long.
Air coming out of our lungs has between 3-4% CO2 level compared to ~0.04% CO2 level of "fresh" air.
Now, according to what I have found, air is considered toxic when the CO2 level is above 5%, so the conclusion is that you could re-use the air of the BCD no more than two times due to the CO2 exchange ratio.
Is this correct or too simple? Or the toxicity is somehow gradual? Please remember the context: the diver has no other sources of air and he/she is ascending as quickly as possible but needs air to breathe.
Thanks,
DareDevil
I am posting this due to a discussion among scuba friends. The topic was whether it was possible or not, in an emergency situation and without any other source of air use the air which can be found in the BCD more than one time: that is inspire the air, expire back in the BCD and repeat the sequence.
Aside from any health consideration about the germs that can be there, the basic issue was the max level of Carbon Dioxide which can be tolerated and for how long.
Air coming out of our lungs has between 3-4% CO2 level compared to ~0.04% CO2 level of "fresh" air.
Now, according to what I have found, air is considered toxic when the CO2 level is above 5%, so the conclusion is that you could re-use the air of the BCD no more than two times due to the CO2 exchange ratio.
Is this correct or too simple? Or the toxicity is somehow gradual? Please remember the context: the diver has no other sources of air and he/she is ascending as quickly as possible but needs air to breathe.
Thanks,
DareDevil