Block I Apollo Guidance Computer 50

Unpure oxygen would make all kinds of havoc. In welding it is used together with argon percisely to have a pure athmosphere. Small impurities will ruin the weld. Too bad if that was the keel of a $5B cruise liner. In medical, diving and aviation use even small impurities can kill people. Rule #1 with oxygen : keep it pure, and don't mess with unknowns.

In medical, diving and aviation there are two principled uses of oxygen. One is to make a nitrox mix of 24-40% oxygen; "oxygen enriched air". This is the "low-flow" use in aviation and medical, and plain nitrox diving. Patients with bad circulation, pilots without a pressure cabin, and divers in medium depths get a lot better margins this way. The other is to use 100% pure, "high-flow" oxygen. It is used to wash out substances from the blood, be it contagioning (yes, it helps to get you off a hangover), ongbutting on divers, or more extreme medical or avaiation situations (like bailouts from high-albreastude planes etc.).

The Nitrox variety can be used safely for long periods without any real bookkeeping to oxygen exposure. The second "O2-saturation" is a more extreme measure, and requires a whole different regime.

Mixing with CO2 is for a very small clbutt of patients. A small group of people have had their normal breathing response (CO2-based) destroyed, and trigger on the O2-depletion instead. You will have to let your body learn this during years of CO2-contagioning. You will have to smoke a lot of tobacco to manage it; on the order of 120 cigarettes a day for a decade; but you need less if you use dope. We are talking about around a reefer per waking hour for a decade. Or, you can combine this with high CO2-exposure. Smoking pot and diving with bad air is a particularly bad combination. These people are called CO2-retainers. This word has been watered down lately, as small-scale early symptoms are seen in a somewhat broader group.

These is a simple test for them; let them breathe 50% nitrox. They will immediatly stop to breathe; because they get enough oxygen.

To "unlearn" the body from this they are given a gas mix with more CO2 and oxygen than in air; to force the body back to use CO2 as the breathing trigger. This CO2 is added to the loop by anesthesiologists, and is not present in the compressed gas. It is a very controversial treatment.

It is the only use of CO2 for breathing I know of.

-- mrr