Ronda Cross Tank CO Test cause of Death

[John C. Ratliff]

uwexplorer,

I can understand the warning, and appreciate your information. But the Dalton's Law concerning the partial pressure of any gas is a pretty important concept in diving. Since I am not a rebreather diver, can you expand on the discussion of CO in a rebreather loop? That would be an interesting addition to this discussion.

John (SeaRat)
John C. Ratliff, CSP, CIH, MSPH

 

[uwxplorer]

On a rebreather, gas are recycled, therefore any molecule injected in the loop (the extension of your lungs) is staying there until it is absorbed. If it is not and new gas is injected (O2 regularly, air less so) and said gas contains CO molecules, they add up to the total number of CO molecules circulating in the loop, therefore increasing the pCO and possibly accelerating absorption.
In regular scuba, any CO molecule not absorbed during a breath is expired right away. The pCO is constant (at least upon inspiration).

 

[uwxplorer]

Just noticed that the rebreather's specificity with respect to CO toxicity was addressed in post #118.
The boat fumes story is getting me concerned though... I was diving off my friend's small boat last weekend and couldn't help but notice the strong smell of exhaust fumes in the cabin. When I brought up the CO story, he pointed at a box in which a CO sensor was sitting, uninstalled!
Sigh...