Tonicity matters too. Deionized water will suck the ions right out of you. All the way to your death if you're so determined.

> That said, the state of mind must be so wild that "is it poisonous in this specific/usual sense" is probably not the right thing to discuss.

I've struggled to tell the difference between doses of LSD that exceed 100µg. Maybe I just take it too frequently to make much of a difference. It's also possible that it only increases duration, but not intensity.

Fentanyl is actually much more toxic than the mycotoxins produced by mold (which I'm guessing is what you're referring to), and yet fentanyl is generally recognized to be a useful drug because of its therapeutic effects. If something has no possible therapeutic, recreational, nutritional, or culinary effect, while being toxic, it might be fair to characterize it as a 'pure poison'.

That's purely because it's usage is accepted nearly as a default, and drug in common usage is most often a pejorative term if it doesn't refer to a medicinal context.

Most people who use drug as a pejorative term also wouldn't use it to describe caffeine.

> Alcohol requires an astronomical intake compared to most drugs

That's primarily because it's most commonly diluted 90%. Spirits (or everclear) have much lower intake required.

But the "Active dose" to "lethal dose" ratio, aka "therapeutic index" of alcohol is pretty bad.