I don’t think it’s actually used for welding though? The cylinders they used to use in dentists offices are pretty big too.
Here's the thing. Nitrous oxide isn't used in welding. Nitrous oxide, as the name implies, is an oxidizer. You generally don't want oxidizers in your welds, because it introduces impurities that weaken the root of the weld. Welders mostly use argon or carbon dioxide, sometimes a mix of both; inert gases that push atmospheric air away from the weld as it is being created. Rekieta can't just walk into a welding supply store and ask for a 100 pound tank of nitrous oxide because they'll likely not even have it stocked.
Even then, the nitrous oxide bottle itself (when used in racing applications) contains a valve with a siphon tube that goes down to the bottom. When you use it, it injects liquid, not gas; this is why nitrous cars have that scenic white spray coming out of them whenever they're just about to race, they're purging the gas out of the nitrous lines.
This is kind of relevant because you can't show up to a speed racing shop and have them refill whatever 10 pound tank you bring (like say a scuba tank), it has to be an approved nitrous oxide tank with an approved nitrous oxide valve. Not to mention the bottles themselves are filled to 900+ psi that aren't regulated. If Rekieta puts his mouth on it to take a huff, as soon as he opens the tank he'll have his teeth blown out the back of his head.
It is the same gas… but I googled it, and whaddya know!
“Automotive-grade liquid nitrous oxide differs slightly from medical-grade. A small amount of
sulfur dioxide (SO2) is added to prevent substance abuse.”
This is correct, and it not only applies to nitrous oxide used for racing, but all types of inhalants, like computer duster. If you look at the SDS for racing nitrous oxide, you can see it does have a <0.1% of sulfur dioxide, although even that could be enough to make it bitter.
Although, on second thought, maybe he
is inhaling racing nitrous oxide after all.
Bottom line being, Rekieta is restricted to only small canisters, considering any food or medicine canisters of nitrous oxide are incredibly difficult to get your hands on (for obvious reasons), and any non-food and non-medical bulk amounts of nitrous oxides already have chemicals to try and prevent people from abusing them.
