I chanced across the website of American campaigning journalists Propublica yesterday. The organisation was founded by a bunch of ex-New York Times writers, so you can probably guess the kind of thing they write. I was struck, however, by their analysis of the contents of fraccing fluid, which included this:
Yes, they have relabelled sand as "crystalline silica", adding a picture of heaven knows what, and a skull and crossbones. Evil crystalline silica is, we are led to believe, a dangerous carcinogenic.
Helpfully, they have provided a link to an official materials safety sheet. However, the title of this sheet reads:
Silica, crystalline (as respirable dust)
OK, so the dust may be carcinogenic. And are fraccers using powdered sand or just ordinary sand? The answer is here in an article about the boom in sand mining brought about by the fraccing revolution.
The highest-quality 20/40 mesh [a size measurement] sells for roughly US$75 per ton currently. 30-50 mesh is around US$70/t; 40-70 is around US$60/t; and the 100 mesh is around US$40/t, but that depends on the plant.
Sounds like ordinary sand to me.