> >"Gios Blue" contains cobalt, highly toxic and indeed illegal in paint in
> >most places.
I should have written read "Gios Blue contains a cobalt base which is highly toxic and indeed illegal in paint in most places"
The pigment may well have been Cobalt Arsenate, a once-popluar violet pigment which has been banned in the USA since the 1960s.
Aldo Ross
Middletown, Ohio
>
> Not true... cobalt is a common and easy to get pigment and is used all
over
> the place. It's replacement in many blues is motivated not by toxicity,
but by
> expense. Cobalt oxide from my ceramic supplier was going for $35 a pound
> last I checked and cobalt carbonate was only a few bucks cheaper (compare
this to
> well under $10 a pound for almost everything else, copper carbonate,
chrome
> oxide, etc.)
>
> As to cobalt being highly toxic, no more so than most other metal oxides
used
> as pigments. I am equally careful of chrome, cadmium, copper, vanadium,
> etc... don't ingest the stuff in glaze/paint form and wear a respirator
when
> working with it in dry powdered form. Most of the oxides and carbonates
are safe
> with these simple precautions (the chlorides on the other hand are a
different
> ball of wax... they can be absorbed right thru the skin)
>
> Bob Hovey
> Columbus, GA