Linda Coscarelli at Bixby Medical Center in Adrian MI asks about disposal of 
mercury containing fixative such as B-4, and Eric Kellar (U of Pittssburgh) 
responds by citing the Dapsons' recommendation that you precipitate the 
mercury with an alkali.

Further treatment with sodium sulfide yields black, extremely insoluble and 
inert mercuric sulfide, which one could store a great quantity of before 
needing to dispose of it. You have to know enough high school chemistry to 
calculate how much sodium sulfide you need. How hazardous to handle is sodium 
sulfide? Because of the toxicity and bad smell of hydrogen sulfide, I 
wouldn't want to handle it without a hood, a facility not available to 
histologists in most small labs. Do the rest of you think this procedure is 
practical?

I've found an odd complication of keeping a bottle of mercury waste: people 
who break mercury thermometers want to put the mercury, the glass, and the 
clean up materials in my mercury waste, greatly increasing its volume.

Bob Richmond
Samurai Pathologist
Knoxville TN