If you preserve opened wine with argon, when you go to pour it again, what happens to the argon gas? Do you drink it and get poisoned?
Helium, Neon, Argon, and Krypton are stable noble gases. https://www.ptable.com/ They tend to be non-reactive and argon in the bottle is to push out oxygen. The safety concern is only in diplacing oxygen, and there is not enough used to suffocate you in a room. Although argon can dissolve in wine like oxygen, it doesn't tend to stay that way because it is unreactive and letting the glass sit should dissipate it. It isn't considered harmful in small amounts.
It just escapes into the air when you open the bottle again. There is a tiny amount of argon in the air we breathe anyway! It's not poisonous. Argon is one of the "noble gases" that doesn't chemically react with anything, so it can't possibly poison you. What it does in a wine bottle is to keep the reactive gases out, particularly oxygen, and that's how it preserves the wine. The only thing argon can possibly do to you is if you breathe an atmosphere full of it, and then you will suffocate because you're not getting oxygen. But the amount you would have in a wine bottle is FAR FAR too small for that.
The Oracle of Omigod
Argon is not poison but is simply a part of our air that does not promote oxidation and germs.
Argon is non-toxic - no worries
The wine goes into the glass while the gas falls to the floor because its heavier than air.
Who uses argon? The cans I have seen are filled with nitrogen.