I just did a bit of an experiment. My lab uses Kimberly Clark nitrile gloves, and we have a huge jug of acetone. First, I put a glove on my hand, and poured acetone all over it. My hand felt cold, but not nearly as cold as it feels when I spill acetone on my bare hand. I allowed the acetone to evaporate from the glove (approximately 30 s), and removed the glove. There was absolutely no acetone on my hand or the inside of the glove. I then took a fresh glove, and poured enough acetone into it to fill the fingers with acetone. I held the opening shut for about 5 minutes, and poured out the acetone. During that time, the glove slowly felt thinner and easier to stretch. At the end, it was so thin that it tore with almost no effort. So for the particular pair of nitrile gloves and acetone, it looks like somewhere between 1 and 5 minutes' exposure will render the glove useless.