This was so long ago, block disposal of human tissues in clinical setting
as it pertained to me, mercury was still used willy nilly and was still
drain dumped. (over 20 years ago!)

How this is done now is another good question?  But I also recall, we did
not use mercury fixatives like B5, pathologists were used to NBF, and
used it almost exclusively.  It was not the fixative that was a problem then,
it was the dumping of hematoxylin made with mercuric oxide that would have
been the big problem and poisoning the fish in our Montana blue ribbon trout 
stream.  

I assume one might have to collect ashes ???? from incinerator, then dispose of
these correctly???? to contain any mercury residue.  

I can say that mercury fixatives and solutions, today, are banned from our 
histo lab.  

Gayle Callis