My assumption is that it isn’t safe to eat regular, unblended glass not because of its composition, but because it’s probably not a good idea to chew or swallow. Wiki lists several compounds present in glass, but I’m not sure if any of those are inherently dangerous to the human body. And if so, would there be sufficient quantities in, for example, a 10 oz glass soda bottle? For the sake of argument, let’s say we’re blending it with water (or Coke, if you prefer).
Again, not planning to actually partake in the ingestion of blended glass beverages, but it would be good to know in a world’s end situation where I’m left with nothing but a glass bottle and blender.
Leaded glass would cause problems, as the acid in your stomach will encourage leaching.
You might run into trouble with CaO raising the pH of your digestive system, but I’ve never measured the pH of a powdered coke bottle, so don’t know for sure.
Also, if the stuff is powdered fine enough, you might get gel formation in your intestines and clog things up; not that eating 10 ounces of sand would be good for the digestion in the first place.
Glass, ground finely enough, is safe to swallow. My Dictionary Of Misinformation cites a British case wherein a doctor ate a spoonful of ground glass in open court to prove this point. The old carnival trick of appearing to chew and swallow a light bulb? They really do chew and swallow an ordinary bulb. Glass won’t cut the teeth, and again if chewed into fine enough bits it won’t cut the digestive tract either.
Please note, eating glass is a lot like tight rope walking. It can really be done, but serious injury tends to result if you don’t know exactly what you are doing.
Have you ever seen this guy? He ate multiple bicycles, TV sets, and even a whole airplane. He doesn’t look that healthy to me but your question is trivial compared to what he did and he lived.
I made the association and further research shows that it is you. Stop eating perfectly good airplanes. I would love to have one and I would gladly send you 1000 feet of chain, 20 pounds of concrete, and 500 pounds of marbles in exchange for one.
It’s worth mentioning that his career choice has left him with rounded, worn stumps for teeth. As others have already said, I imagine the extent of internal damage would depend primarily on the nature of the glass particulate.
For what it’s worth, David Niven’s autobiographies have several mentions of such-and-such a person eating a champagne glass during various festivities. I got the impression that among the Hollywood set of the time it was the drunken ‘hey y’all, watch this’ trick to show how cool and manly you were.