The main risk is kids eating it. If you are an adult there is little risk other than
sitting and making a meal of it. How ever, breathing any kind of dust is bad.
So a simple dust mask is in order, or you could wet sand. Sand blasting in
a cabinet is good. To minimize the spreading of dust, wet the floor while
sanding. A 20" box fan with a 20X20" home heating type filter with trap
most of the air borne dust. Keep all children away from the work area.
Sweep up all dust or vacuum with a unit that has a bag and make sure
you don't throw it in the regular trash, take it to a disposal site.