An interesting fact, passed to me by  "my son, the doctor" is that inhaled
powdered sugar is really nasty in the lungs.  The condition is known as
"Bassinosis" (sp?), . Bakery workers, sugar cane harvesters, even those who
frequently consume powdered sugar doughnuts are at risk.  This has the
potential to be very serious, with ulceration or possibly surgery a
potential, and he cautions using it only outdoors, or in very good
ventilation.

EDW