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Comment by Aurornis | Hacker News Reader

The prices in the article are what the company is charging for their services, not the gas itself.

The gas itself is under $100 per liter depending on purity.

The depending on purity is doing a lot of heavy lifting here, to the point where I would say it's misleading. I don't know the price for xenon off the top of my head, but for a comparison with nitrous oxide, food grade is generally between 99% and 99.9% pure. If you want medical grade, the threshold is 99.99% pure or better, depending on what you're doing. Those additional nines are what drive the price up, plus the fact that someone signed off on it with their name. Food grade is cheap, medical is expensive. No one is going to go up Everest with anything below medical.

> The depending on purity is doing a lot of heavy lifting here, to the point where I would say it's misleading.

Not really. The range of prices doesn't change by multiple orders of magnitude. At small quantities the cost of the ancillary equipment might be as much as the gas. I guarantee you they're not buying $5000 of pristine gas per client.

One of the hardest parts of dealing with Xenon is getting the last little bits of Krypton gas out. Very small doses of Krypton gas are inert and not really a health issue. The research grade Xenon has to be higher purity because many experiments rely on it being the only gas present.

> No one is going to go up Everest with anything below medical.

Companies who do Everest expeditions vary greatly. There's a lot of history of bad behavior among companies around Everest. Just because it's expensive and their clientele is wealthy, you shouldn't assume they're operating according to the highest standards. There's a long history of badly behaving companies around Everest.

But why would it even be bad behavior to use "food grade" Xenon? They extract it from air, and they're going to mix it with air again.

Because the contaminants in that 0.01% can be byproducts of the refining process and not necessarily what was in the air originally.

Like what, lubrication from the air liquification equipment? I guess I don't know much about the details of the process, but I really don't know what the contaminants would be.

Yes, or random things like minor amounts of carbon monoxide or nitrous oxide or what have you.

One reason why it’s not a good idea to use a normal air compressor to breath from (or compress air for cylinders), is precisely because of issues like this.

No one here is claiming they're charging that purely for the gas. Of course you have equipment, personnel costs, maintenance, profit margin etc on top. The point is that the cost of the gas is not trivial.

What does the additional .09% of purity get you - if the xenon or nitrous is mixed with air at inhalation time anyway? For example, divers and pilots use ABO oxygen which is only 99.5% pure.

https://www.aopa.org/news-and-media/all-news/2023/december/p...

It's often what the 0.9% is that makes the difference between grades, other than purity.

Generally and as an illustration, a chemical may have a 99% "reagent" grade that includes industrial solvents or some other chemicals that are toxic to ingest. So its equivalent "food" grade may have the same 99% purity but the other 1% is something that isn't poisonous.

My chemistry teacher pointed out to our class that "99%" ethanol was distilled in benzene, and therefore had poisonous residue, whereas "95%" was water distilled, and thus safe to spike your OJ.

In the US they generally add toxic chemicals back in for that kind of thing to prevent people doing that.

They might generally add toxins (or bitterants) to the 95% if regulations instruct them to.

With the 99% stuff, the laws of physics compells them to use the benzene.

Financial considerations also exert an influence on the process.

Such toxins are added to make the alcohol unsuitable for human consumption, and thus avoid paying government alcohol tax or duty.

Where I am it's called "methylated spirits" and IIRC the boing point of the additive is very close to that of the alcohol so it's not possible to distill it out.

20 years ago I read about a Dutch company that sold pure alcohol for consumption to Russia, where people would drink one sip of pure alcohol followed by two sips of orange juice.

Hopefully the only country with a market for that.

> The gas itself is under $100 per liter depending on purity.

At what temperature and pressure?

STP, standard temperature and pressure, most likely. Commerce may vary the temperature slightly, but I doubt by much.

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