I would think in small amounts it would do no harm. If you are spraying a large quilt doing it outside might be better.
If you have an outdoor clothesline, it might make it easier for you to do. You could take it back in to add the next layer.
Or, if you could do it in a kitchen and have the stove fan and some other fans blowing it away from you it could work too.
JMTC
Lyette