That's odd (though perhaps not altogether surprising, given the normal paranoia) as bismuth (note – by convention, chemical names are not capitalised) is one of the least toxic, least bio-accumulative of all the heavy metals, and its compounds have been used in medicine for decades (especially in indigestion relief!). Although many of its compounds are toxic in larger amounts (what isn't – sodium chloride is lethal in large enough amounts) the metal itself is considered fairly harmless.
Was there some special reason it was considered unsuitable in your application?
David
Edited By David Littlewood on 06/06/2013 22:37:53