Young and not bent

[Genesis]

There are various "grades" of Oxygen.

The only one regulated in the US is "Oxygen USP", which is a medical gas and requires a prescription to obtain and use.

"Avaitor's Breathing Oxygen" is, as the name implies, intended for human consumption (typically by owners of unpressurized light aircraft.) It is also what most dive shops typically will obtain and use for mixing PP fills of Nitrox and Trimix.

It is NOT a prescription drug and is perfectly legal to obtain and use for diving purposes, either at or below the surface of the water.

(That's what I have on my boat.)

There are also laboratory grades (which instead of being 99.5% O2 might be "five nines" or "eight nines" pure), and welding gas, which is at least 99.5% pure as well - it has to be for oxy cutting torches - but the cylinders and such used to store it could conceivably have contaminants in them that would make it unacceptable for breathing purposes. The lab grades are gross overkill (and overly expensive) for diving use.

 

[The Iceni]

Genesis once bubbled...
There are various "grades" of Oxygen.

The only one regulated in the US is "Oxygen USP", which is a medical gas and requires a prescription to obtain and use.

"Avaitor's Breathing Oxygen" is, as the name implies, intended for human consumption (typically by owners of unpressurized light aircraft.) It is also what most dive shops typically will obtain and use for mixing PP fills of Nitrox and Trimix.

Same grades over here, Genesis,

Aviation grade is the most expensive, but is simply drier than the others to prevent it freezing the pilot's regulator at altitude in the cold. Most UK dive shops sell medical grade, which is not "prescription-only" over here, and is much cheaper.

BOC sells a 9 litre cylinder (200 bar) for about £5.

In the 'states you are clearly being overcharged for dry oxygen you obviously do not need!

Strange what knock-on effects the classification of medical gasses can have.

Perhaps I should prescribe a few dozen cylinders for you!!!

Have you voted?

 

[Genesis]

I bet you can't prescribe for me though - is a UK doc's script valid in the US?

 

[The Chairman]

my supplier handles only medical grade oxygen, and according to them... they are required by Florida law to sell it to anyone who presents a valid SCUBA card, from any agency. No, not NitrOx or advanced NitrOx or anything like that... just a plain ol' OW card gets me all the Oxygen I care to pay for. If they are in error, then I am happy for it, as it expedites getting oxygen for my crew.

 

[Genesis]

of this Florida Law, but haven't been able to find it. And with the statutes being available online, its pretty easy to find...

Florida DOES have a "Oxygen USP requires a script" law, and I can't find the exemption.

I have a shop here that will sell me the stuff out of their cascade - the same stuff they blend Nitrox with - at roughly the same cost for a tank as a tank of Nitrox (even though the tank holds fewer cuft of gas - they don't price by the cubic foot, but rather by the tank...)

Its pretty inconsequential in terms of the numbers; $10 to fill a Jumbo-D isn't enough to matter from my point of view.

 

[The Iceni]

Genesis once bubbled...
I bet you can't prescribe for me though - is a UK doc's script valid in the US?

No indeed, I am not "State certified" although I do have a US passport!

You are allowed to import any medicines I may have prescibed for you in the UK but suspect air fares and shipping costs may make this a tad uneconomic.

I gather that the web is often used to circumvent our Medicines Act (for example, Viagra).

I think this law is long overdue for reform, in regard to divers' use of oxygen at least.

 

[Genesis]

in that we're widely known as the "geezer retirement home", especially the southern part of the state.

I'm sure the law was well-intentioned, in that there are an awful lot of older folks down here who have smoked their lungs to death and now rely on O2 to be able to get enough oxygen in their blood at all, at least part of the time, and monitoring those sorts of conditions is pretty important.

But the unintended consequences are another matter entirely.

Not all scuba shops have the adapters to be ABLE to fill pin-indexed tank valves from their cascade tanks. If you have the adapter, then its no big deal. But if you don't......

If there is a cost difference I don't know what it is, but if that contributes to this I'm a bit unhappy. I'll be a whole lot more unhappy if I start doing planned-deco dives and the gas costs are doubled as a consequence of this law (having to use Aviators, and it being more expensive.)

 

[The Chairman]

for Oxygen in Florida... take it down and get it filled with medical grade O2. It ain't all that exspensive, and they have the fittings right there. I get my get tank filled for $7.50 and the small one for $6.00. Just present your C-Card and have them research the law for you.

 

[Genesis]

thanks!

 

[Scuba]

Genesis wrote the following attributing it to DAN, (They refers to DAN)

They recognize that deciding to consume the O2 may in fact prevent a hit you would otherwise take, but that it also may not, and there is no way for you to know if it will or, if you don't get hit, if it did, or whether or not such a hit's severity would be changed .

Dr. Deco wrote:

Breathing oxygen will speed the off gassing of dissolved nitrogen and than in bubbles also.

You can assist nitrogen elimination by breathing oxygen

Oxygen will not “mask” symptoms; it is not an anesthetic or any other type of anodyne (pain reliever).

Several question:

If oxygen speeds off gassing of dissolved nitrogen and helps eliminate nitrogen, would it not then reduce the severity of the hit if taken a certain amount of time before treatment can begin and severe symptons appear?

When a nitrogen hit, DCS occurs, does the "damage" occur all of a sudden in the form of a jolt, where the possible damage by the remaining nitrogen is negligible? Gradually increase in severity? Prgress in some type of fashion dependant on the level of nitrogen remaining in the system?

How long does it take for oxygen to start eliminating nitrogen from the moment its consumption begins? How long before a significant reduction occurs? Is the rate of elimination known?

Even though oxygen does not "mask" symptons of DCS, does it present some potential problems with diagnostics and treatment of DCS?

Genesis mentions emptying the bottle of oxygen, what size?, for a blown deco obligation or rapid ascent. Dr. Paul Thomas mentions breathing from the oxygen bottle for one or two minutes after climbing a ladder or after certain dives. How long should one breath oxygen if one has blown a deco obligation or had a rapid ascent after a deep dive, and shows no symptons of DCS. Not looking for medical advise but informed expert opinions.