Comment by zeotroph

I was wondering why this material is so bad, it seems to be because it is mostly silica crystals. Without the resin holding it in place such a material wouldn't be possible.

90–93%: 99.9% pure silica in grits and powder form constitutes; 7–10%: Matrix of unsaturated polyester resin with catalysts to help with ambient temperature curing, according to https://en.wikipedia.org/wiki/Engineered_stone

Technically you can safely handle it, just like technically you can have lead or even asbestos in a lot of places. But some poorly paid worker ends up with ruined health in the end, so I can totally understand the ban.