Hm, It's not really being too heavily "interfaced" with the body. I wouldn't stick it under your skin, but this would probably be fine I think. I'd also think that most things are unsafe in molten form, heh.
Well, people put BPA in plastics even though it was known to be toxic because the thought was that the material would bind the BPA in place (i.e. it would always stay in the material).
