Anyone have an educated guess (or personal experience) with this? Do they taste very similar or different?
And is rubbing alcohol that much more poisonous/deadly/dangerous than the same volume of rectified spirits? If so, why?
I’m asking for similar reasons to my last thread about cocaine. Another fictional murder scenario… where someone is already very drunk from whiskey. Would serving them a few ounces of rectified spirits (cut with something sweet to mask the taste of course) be enough for them to get lethal alcohol poisoning? If not, would the same amount of rubbing alcohol work instead? And that’s why I started wondering about the taste difference… Mixed with juice, would it be noticeable?
So yes, you’ll likely get drunk if you decide to drink rubbing alcohol, but it will also taste awful, will burn your throat for days afterward, you’ll be throwing up due to the fact that it’s been denatured, you’ll most likely need to go to the emergency room, and, oh yeah, the chances of it killing you are pretty good.
The short answer is: it depends on what exactly you pour into their drink.
“Denatured alcohol” is any of a variety of mixtures in which ethanol (the normal dinking-alcohol alcohol) is made deliberately undrinkable by cutting it with substances that taste terrible and/or are toxic enough to make you sick right away, before you drink much.
“Rubbing alcohol” is one of either:
denatured alcohol made with chemicals that make it undrinkable but are not harmful by contact (at least in the concentration used); it’s usually a high priority to make it foul enough to be completely undrinkable by any sane person, and I’ve bought some from drugstores that contain stuff like phenol, which you’d probably notice immediately.
70% isopropanol, which tastes and smells somewhat unpleasant but not to the extent that it couldn’t be masked. It’s not usually made deliberately offputting, but it’s toxic all by itself, although not as toxic as some of the stuff used in denatured alcohol.
People regularly die from drinking either, mostly alcoholics who are desperate for anything that might make them drunk, people attempting suicide, or kids getting into the medicine cabinet (more common for isopropanol, since the entire goal of denatured alcohol is to be undrinkable). For your purposes, I’d think you’d be more likely to get the victim to consume a fatal dose of isopropanol, but it would still be something of a stretch.
Isopropanol can be ingested in small amounts with no obvious effect; larger doses (an ounce or so) will cause vomiting and “drunkenness” and possibly metabolic effects that will put you in the hospital for a couple of days. For an otherwise healthy adult, it looks like you’d have to get them to drink around 200-300 mililiters of the stuff to be reasonably sure of immediate death; if you dilute it down to 20%, for a stiff cocktail, that’s around a liter of fluid. So unless the victim is the type who is comfortable drinking Thunderbird straight out of the bottle, it’s not going to be just one drink, more like a pitcher of sangria.
A not-acutely-fatal dose will land the victim in the hospital with symptoms that don’t match standard alcohol poisoning, at which point it will be obvious that something is up.
I’ve heard that one antidote for methanol ingestion is the give ethanol as they compete for the same metabolic pathways greatly slowing the release of the deadly byproducts of methanol. Perhaps the already ingested whiskey could offer some protective effects against this plan?