So don't bloody well drink anything above 190 proof, ever, no exceptions! Though when you're going through 55-gallon drums of it to clean clean-room equipment, a lot of it tends to end up in the air... turns out you can get enough alcohol in the air to get noticeable effects on you.
Like I said, lots of ways to kill you.
Also the really high purity stuff (for HPLC and the like) has the "fun" chemicals removed from it and a chemical analysis printed on the side of the jug. Benzene content can be well below safe drinking water standards depending on the product. Pretty sure you'd be paying more at that point than just buying taxed vodka though.
Fun fact though: it’s not 100% ethanol for long after you open the bottle because it will absorb water from the air until you hit the azeotropic limit.
Downsides: It's flammable and you wouldn't want it accessible with kids around.
Everclear is 151 in states where it’s not legal to sell spirits of higher proof than that (for example, California).
I discovered this little disappointment while attempting a limoncello recipe that called for real Everclear and all I could legally buy was the 151 proof version.