I'm just amazed at the idea that a chemist would put anything in a lab near their mouth. Like, even ignoring acids, there are so many nasty chemicals that are toxic on a measure of parts-per-million or parts-per-billion that I'd be too concerned about accidentally getting a molecule on my lips. I remember reading about how dimethylmercury is so nasty that if you come into contact with it your only chance of survival is to grab a butcher knife and immediately hack off the contaminated limb (that's kinda hyperbole, but it's nasty shit).

Then you have basically anything that contains fluorine.

Maybe those were the days before they discovered the "instantly kill you dead with a single molecule" chemicals.