Where do you find this?
Insulation on the underside of roofs and sometimes sides of buildings and warehouses. Also used as fire protection on steel and reinforced concrete beams/columns and on underside of floors.
It was very easy to overspray or get a 'splash back' from the equipment used to apply this so there is likely to be debris around the sprayed area.
What does this look like?
Usually white or grey in colour with a rough surface, although they may have been painted.