What else can cause severe allergies?
Antistat rags in the dryer, deodorants, brighteners and scents in laundry detergents, latex gloves, and common household molds and fungi. Of course there is dust mite dust, skin flakes and the grand total for common dermatological tests number 60. And this is just for things around the house!
I would not worry about most of the photographic chemicals when faced with hundreds of irritants.
Oh, and the photo companies eliminated formalin from coatings and process solutions so we are only exposed to it wen we buy a new shirt or new furniture. Formalin is used in glues, paints and sizing materials that give us permanent press shirts.