ACTSNYC@cs.com on thu 18 nov 99
IVOR WROTE:
SNIP
> I use cadmium based paints as watercolour. They are made form Cadmium
> sulphide
> and Cadmium seleno-sulphide. In the hand book ( Kurt Wehlter) it states
> clearly
> under Toxicity that they are not poisonous as paint pigments. Is this
> information now out of date? <
Greatly out of date. This was the propaganda that the pigment industry
pushed for years on the basis that the cadmium pigments are not very acid
soluble. They made the assumption that it would go through the human gut
essentially unchanged. Turns out not so.
And by inhalation, insoluble is worse! Now you have a contact carcinogen in
a particle size that can get right down into the alveoli and take up
residence.
The last time the pigment industry tried to make their case for these
pigments being safe was in 1992 when OSHA published the Cadmium Standard.
OSHA rebutted all the pigment industry's lousy data. In fact, one of the
arguments OSHA rebutted was Woodhall Stopford's, the ACMI toxicologist that
certifies the labeling of art materials!!! At that time, you could still see
"non-toxic" labels on cadmium paints and inks!
Now, by law, you have to treat these compounds like any other cadmium
compound.
This means, if you are using cadmium in any workplace: a school, a business,
or any other location where there are employees, you first must do personal
monitoring of the workers using it. If the amount they are exposed to is
over the action limit, you have some very expensive medical monitoring,
ventilation, and personal protective equipment requirements. Even if it is
below the action limit, you have repeated monitoring every time personnel or
jobs changes, and intense record keeping requirements.
The schools that use these pigments or cadmium-containing metals in ways that
can become airborne are almost all in violation of this OSHA standard.
> Ah, yes. Apparently Cadmium sulphide can react with Sodium chloride at high
> temperatures to give Cadmium chloride which boils at about 960C (1760F).
So
> I will avoid putting any cadmium compounds on my pots when I next fire the
> Salt Kiln.
The stuff fumes without being a chloride at even lower temperatures, too.
You weren't on this thread when we discussed the difference between boiling
points and melting points with respect to fuming. Check the archives.
> Ivor, who enjoys using stains for underglaze decoration.
And should love seeing that lab data come back in nice neat envelopes.
Monona Rossol
ACTS
181 Thompson St., # 23
NYC NY 10012-2586 212/777-0062
ACTSNYC@cs.com
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