🚀 go-pugleaf

Beryllium Oxide is dangerous if you inhale particles of it.  It 
causes granular tumor-like formations as I recall.  I don't think
they are malignant, but if you get enough of them they interfere
with breathing.  We used BeO to support Yittrium Iron Garnet spheres
in (YIG) oscillators for a while, and when one of us accidentally 
broke them, I'd run out of the room for a few minutes.  One day a
nuclear engineer friend of mine told me that the guys who were  
actually having trouble with berylliosis were machinists who ground
the stuff in big shops where the dust was so thick that you couldn't 
see from one end of the shop to the other!  Even their family members
would show signs of granulomas as a result of the large quantity of 
dust on their clothes.  They now grind and machine such things under
cover, or in oil or other liquids to keep it out of the air. 

As far as I know, the metallic form is safe to handle without protection,
though I'd be careful if I were grinding it into dust. 

All the best to you,
Ray