When I spray I wear a paper mask - the type the construction and landscapers use. It keeps the spray out of my mouth and nose - and I have a ceiling fan overhead going gently so it is pushing it down with the windows and door open.
If you can spray it outside, all the better. If you are super sensitive to chemicals then I would not use it at all and would go with the Elmer's School glue route. Because after it is all together you still have to handle it to quilt it. It does not bother me and fumes can send me into a migraine, but handling the spray basted quilt does not.