Agree with what Scotty says. All the "good stuff" is unfortunately quite toxic so you do probably need a fresh air respirator and full suit for this stuff and a paint booth.
In my research the industry does not yet have a true non-iso system yet. I was surprised to find the water based system still uses a isocyanate hardner.
If you don't need a clear there are several safe alternatives. And if need a clear but don't care if it is 'crystal clear' you can actually get away something as simple as Varathane which only has a slight amber quality and quite easy to shoot.
I'll be checking out some of these epoxy clears. Could be like the old Hobby Poxy clear(although who knows how safe it actually was).
I've had some success with spar urethanes but they take forever to dry.