(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....)