I don't know if you have access to Den of Angels.com but there is a huge thread about staying safe when using spray sealants.
http://www.denofangels.com/forums/showthread.php?399096-What-you-need-to-know-about-respiratory-protection!
"Many of the items that we work with as doll customisers are toxic and many of them are cumulatively toxic. You may feel ill for a while and then get better, but the sorts of diseases that can be caused by sanding processes and spraying processes can come back to haunt you many years down the road. These products can cause Cancer and Pneumoconiosis. Cancer may be treatable if caught early enough. Pneumoconiosis, which is respiratory diseases like asbestosis, silicosis and coalworker's "black lung" disease, is NOT TREATABLE....
...
This includes all types of spray applications, whether you are spraying sealant (like MSC or Testors) or airbrushing or spraying paints.
The process of spraying releases aerosols (and this is true whether or not you are using an aerosol spray can product. Airbrushing paint creates aerosols too!) for which an N95 filter is not effective."
I would probably just spray it outside to be on the safe side.
Also, it's respectful to your bf's mom since not everyone would be comfortable in having chemicals sprayed in their homes. I spray out side since I have lovebirds and birds are notorious for being super sensitive to air born things. Hence why canaries were once used to detect fumes/gases in coal mines and such. The birds would succumb to the noxious gasses way before human workers would and a dead bird meant everyone to evacuate the job site.
I don't burn candles, use hair spray or such and I am really careful not to use non-stick/teflon pots and pans because over heating these creates fumes that kill birds too. It's amazing that every day home items when misused can cause health issues and we don't even know it!
In my apartment, when someone moves out of a unit, the paint guys even wear little masks when they refresh walls and such with paint.