Kris Griffith on thu 6 mar 97
------------------
I am posting this for a friend who runs a clay manufacturing business. He =
does
a great deal of business with schools. We were discuss the thread about
manganese dioxide, come to find out that is an ingredient in one of his clay
bodies. I told him according to our discussions here, that body would be =
toxic.
He is interested in finding out how to have his clay body and or formulas =
tested
for toxicity. He would like to tell schools his clay is non-toxic. Amoco
labels all of their clay bodies =22non-toxic=22. Can you tell this from =
just
looking at the formula or would the clay body need to be tested. How many =
rats
have to die before the formula is considered toxic?:-)
Please someone enlighten me?
Kris Griffith
Monona Rossol on sat 8 mar 97
Kris Griffith wrote: ------------------
> I am posting this for a friend who runs a clay manufacturing business. He
> does a great deal of business with schools. We were discuss the thread
> about manganese dioxide, come to find out that is an ingredient in one of
> his clay bodies. I told him according to our discussions here, that body
> would be toxic. He is interested in finding out how to have his clay body
> and or formulas tested for toxicity.<
In the U.S. all "art" material's formulas must be evaluated by a certified
toxicologist and labeled in accordance with a labeling standard (ASTM
D-4236). This is the law. So if this is the U.S. and he's asking this
question, he has a big problem. If he is in Canada, I think that he is
only bound by the Canadian Hazardous Products Act which relies on acute
animal tests (see below).
> He would like to tell schools his clay is non-toxic.<
Right there I disagree with this person. The clay is going to contain free
silica so warnings about the dust should be present. Even clay (kaolin)
dust has an OSHA standard because it causes lung disease. The manganese also
ought to be disclosed. Suppose it is in less than toxic amounts for most
people--how will it affect young students who already have disabilities from
neurological problems?
> Amoco labels all of their clay bodies "non-toxic". <
Amaco labels in conformance with ASTM D-4236. This is an example of one of
the reasons I don't like the standard.
And Amaco's label is the only justification I can see for your friend
labeling his product "non-toxic," too. He is competing with this company, so
if he labels with ingredients and warnings, people will assume his product is
more toxic. It may or may not be.
> Can you
> tell this from just looking at the formula or would the clay body need to
be > tested. How many rats have to die before the formula is considered >
toxic?:-) <
THis, of course, is a very intelligent question. The Canadian Hazardous
Products Act, just like the U.S. Federal Hazardous Substances Act, relies on
acute animal tests (Lethal Dose 50 and Lethal Concentration 50 --LD50 and
LC50). Unfortunately, even powdered asbestos will get a perfect score on
these tests because it doesn't harm animals by skin contact, inhalation, eye
contact or ingestion in only two weeks. Things that take years to develop,
reproductive damage, harm to the fetus, and many other longer-term hazards
are completely missed by these tests.
It was to correct this, that the US law incorporating the ASTM D-4236
labeling standard was passed. However, I sit on this ASTM committee, and I
tell you that the labeling standard/law sucks. The tests and rationales for
deciding what amounts constitute toxic amounts, how to determine
bioavailability, and to how much consumers will be exposed are seriously
flawed.
At this point, I think potters would be wiser to educate themselves about the
hazards of all the ceramic chemicals they use and demand disclosure of the
ingredients in their products so they can make up their own minds.
Monona Rossol, industrial hygienist
Arts, Crafts and THeater Safety
181 Thompson St., # 23
NYC 10012-2586 212/777-0062
http://www.caseweb.com/acts/
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