Re: silicon dioxide in protein powders; inhalation health hazard?

This information is provided on a casual basis, and I accept no 
responsibility  for errors, omissions, etc.

silicon dioxide is quartz, and you may know it as the sand you see on a 
beach. It is pretty non-reactive, and I believe that it is fairly non-
toxic. Having said that, the nature of toxicity is that everything is 
toxic; it is the dose that determines the poison. If you eat/breathe 
enough silica, you will have problems. My suspicion is that the protein 
is more likely to be problematic than the silica. 

Under any circumstances, if someone provides you with a protein powder, 
it should have a hazard warning sheet or description which identifies any 
problems. You should consult this, and whoever is responsible for your 
health and safety.

cheers
david

Editor's note:  according to this 
site and the Material Safety Data Sheet (MSDS) for silicon dioxide, 
prolonged (stress: prolonged) exposure to silicon dioxide inhalation can lead 
to lung fibrosis, also called silicosis.  However, this disease is usually seen 
in industrial settings, where LOTS of silicon dioxide is inhaled on a daily 
basis.