Agreed with Ohiofarmer- I have been around Acetone in warehouse environments all my life and have never seen anything negative other than gettin a lil high while working with it. Those metal cans don't leave much room for poor storage.
I understand what Ohio is talking about as well. We are simply using one solvent- butane, under one polarity. That means if you are under full vacuum and can change polarity you can even get a different oil or finished product with same butane. I have not got to this level yet. The key is being under vacuum which molecularly changes everything and allows proper purging.
I too am curious about other solvents as I tried some oil that was made with nitrous recently- tasted great. Not any stronger or any more purged but definitely different.
What makes me wonder is actually the difference in taste, color, effect (cannabinoid content, activity, and degredation) due to different solvents, polarity, and temperature at which its purged. Hot water baths definitely change cannabinoid content and activity due to heat levels. under real vacuum most solids can change state to liquid and this further eases purging especially with a low temp water bath to aide. Sorry for the rant, just some thoughts.