The reason I suggested caution in the use of uranium-based chemicals came from one of my cached issues of Camera and Darkroom (Lord, fo I miss that magazine - even today many of the articles from ten years ago are of current interest). Someone once walked into rather old darkroom with a scintillometer and the thing went *nuts* recording all kinds of radioactivity - at considerably *more* than commonly acceptable levels - all traced to a can of Uranium Oxide (??? something like that) that had been in photographic processing use in the distant past.

I take pride in not panicking easily; at the same time. I would have to place uranium - whatever - in the "risk unknown" category.

I still have vivid memoriies of sifting through thousands (literally) of prints, material lists and specifications, searching for cadmium plated screws - or cadmium-plated anything - once common - so that we could ship our products to Europe.