It is possible to stay and sleep in your house after you've coated your floor with water-based polyurethane because unlike oil, it dries rapidly. It takes about 2 to 3 hrs for it to dry completely. As a result, you are able to recoat your floor the same day. Yet the primary reason why it is safe is that it contains fewer toxins than its oil-based counterpart, and the smell dissipates quickly.