White granulate in the old building above the drywall ceiling

Hello everyone,
I am at a friend's construction site and had to find out that in the "converted attic" above the drywall ceiling white granulate (not styrofoam) was delivered in large quantities. Surely for insulation. What kind of crap could that be???
I have the mask on, still feels awful... Thanks and best regards

Perlite presumably. A mineral insulation material.

Yes, pretty sure perlite. It is commonly used, is fairly natural and non-toxic (just dusty) and quite light. It is also often used as a leveling fill. I used it in my bathrooms and in the utility room as the bottom insulation layer (but for the floor), simply because there were too many pipes crisscrossing to carve EPS there...

Thank you very much for your answers.

Isn't it nice when you suddenly receive such "nice" news after being really shocked at first? I know some who have found completely different things and materials underneath. Perlite is good news!