The word to watch for is Isocyanates which all the moisture cured urethanes contain. You can do a web search and come up with a bunch of information.
Isocyantes are one reason you don't see a lot of old painters around.... Very prevalent in the catalyzed 2 component paint systems used automotively today. It may appear they would not be in the moisture cures because they are a single package product, but you can bet your hat and the house cat, they are.
The requirements are almost uniformly for fresh air supplied breathing gear as the iso's are odorless and you cant tell when you may have lost your seal of a full face mask and are breathing it.....
