It's a 2-part epoxy-like finish. It smells just like automotive 2-part finishes.
The smell seemed to last for about 3 weeks in our house after we had about 1000 square feet done. We felt OK moving back in after 5 days. I think they recommended 3 but that wasn't enough curing time.
If you're more worried about it or are sensitive to solvents, just stay away from the house and wait longer for it to cure. The quality of the finish is worth it.