ᐅ White granules on an old building beneath a drywall ceiling

Hello everyone,
I’m at a friend’s construction site and noticed that a large amount of white granulate (not polystyrene) was spread above the drywall ceiling in the “finished attic.” Surely for insulation. What kind of material could this be???
I’m wearing a mask, but it still feels unpleasant... Thanks and best regards

Perlite, most likely. A mineral insulation material.

Yes, quite certainly perlite. It is commonly used, fairly natural and non-toxic (just dusty), and quite lightweight. It is also often used as a leveling fill. I used it in my bathrooms and the utility room as the bottom insulation layer (but for the floor) because I simply had too many pipes running all over the place to cut EPS foam.

Thank you very much for your answers.

Isn’t it nice to suddenly receive such “good” news after initially being quite shocked? I know several cases where people found completely different materials underneath. Perlite is good news!