It isn't water soluble, so if it got in the lungs it would likely just sit there and do nothing or take some incredibly long amount of time to be broken down.
Niner, as to grinding it, doesn't that just break the molecule into useless carbon?
We have carbon arranged in a molecule with a specific configuration (12 pentagons, 20 hexagons) that has extraordinary characteristics.
Wouldn't grinding it break up the molecule into simple carbon, which would have then lost all of those extraordinary characteristics?
So while I'm happy to hear niner's comments on how difficult C60 is to actually atomize, I'm also wary of the fact that aggregates might "sit there and do nothing" in the lungs. "Doing nothing" in the lungs means blocking the alveoli. So while it sounds like it's not easy to inhale accidentally, once it has been inhaled, it might take an indefinitely long period of time to dissolve into the blood stream and be excreted. Fortunately, taking c60oo will alleviate the negative effects of this problem.
"doesn't that just break the molecule into useless carbon?" -- In theory, no, because we should not expect a chemical change to occur from mechanical grinding. But it's much more complicated than that, in the sense that the mortar and pestel meet one another at various angles and velocities and with varying material composition. At some of those intersections, temperatures could briefly spike into the domain where C60 would react with something in its environment, or perhaps spontaneously dissociate. How likely is this to occur? What new compounds might form? Are these carcinogenic? I have no idea and never will. So in my ignorance I've concluded that I prefer to pay someone else to use a centrifuge.
And the idea of C60 aggregates getting stopped by a HEPA filter is somewhat disconcerting. On the one hand, it would be expected to reduce the cation population in the air, which is probably a good thing. On the other, such trapped C60 is basically a high-surface-area reaction substrate, thus effecting some degree of physical catalysis. Catalysis of what, exactly, depends on what's in the air (paint, cleaning solvents, mold, etc.) or leaching out of the AC condensing coils. Hopefully the reaction products would remain trapped in the HEPA, but who knows. Again, I'll pay someone for their centrifugation.