Funny to see IPA called "toxic". In aircraft manufacturing it's considered the nice and friendly solvent in comparison to the stout stuff like MPK or MEK, and considerable effort is invested in convincing workers to use it when the big guns aren't needed. Or, natch, to get workers to wear gloves when working with solvents.
(Much discourse on industrial safety casts corporations as the bad guys, with considerable evidence, but it is still the case that much safety equipment is bulky or unpleasant to use. Ketone-proof gloves are thicker and less pliable than latex gloves, which is no small consideration when doing fine work under time pressure. Easier to just wear two layers and change the outer glove when it starts to break down. When do you know it's breaking down? When you feel it leaking through. When you feel that, doesn't it mean you're already getting skin contact with the solvent. Well, yes, but....)
MEK has the distinction of being the only material I know of that was simultaneously on both the FDA's "generally recognized as safe" food ingredients list and the EPA's "hazardous air pollutants" list, for which no safe emissions level is recognized. It did eventually get removed from the second.
(Much discourse on industrial safety casts corporations as the bad guys, with considerable evidence, but it is still the case that much safety equipment is bulky or unpleasant to use. Ketone-proof gloves are thicker and less pliable than latex gloves, which is no small consideration when doing fine work under time pressure. Easier to just wear two layers and change the outer glove when it starts to break down. When do you know it's breaking down? When you feel it leaking through. When you feel that, doesn't it mean you're already getting skin contact with the solvent. Well, yes, but....)