ACTSNYC@cs.com on wed 26 apr 00
> ---------- Forwarded message ----------
> Date: Tue, 25 Apr 2000 14:42:45 EDT
> From: Janet Kaiser
> Reply-To: Ceramic Arts Discussion List
> To: CLAYART@LSV.UKY.EDU
> Subject: Re: Leaching/Lemon juice story
> Resent-Subject: Re: Leaching/Lemon juice story
> ----------------------------Original message----------------------------
>
SNIP
> I am personally far more concerned about the chemical and gaseous
"leaching"
> from paints, preservatives, adhesives and man-made products like MDF. The
> formaldehyde content of the later in particular.
>> Janet Kaiser
> The Chapel of Art, Criccieth LL52 0EA, GB-Wales
> Home of The International Potters Path
> TEL: (01766) 523570
> WEB: http://www.the-coa.org.uk
> EMAIL: postbox@the-coa.org.uk
>
Absolutely. Potters have no corner on toxicity. I too worry about MDF and
also the very fine particle size of the dust which makes it difficult to
control.
Then there is leaching of phthalate plasticizers from the polymer clays. I'm
very interested in what happens to these products on the other side of the
pond now that the European Union Product Safety Emergencies Committee
approved a ban on phthalates in children's toys. I wonder if the ban will
includes the polymer clays which expose children directly to phthalates by
both skin contact and inhalation when they fire the "clay" in the kitchen
oven.
You also worried about traditional pottery industries dying. Doesn't seem so
in some cases. I'm particularly familiar with the problem of Chinese
traditional ware (the brightly colored ware with all the little details)
which leaches incredible amounts of lead and cadmium. The Chinese and the US
FDA signed an important memorandum of understanding regarding ceramics that
specifically addresses, among other things, this traditional ware. The
Chinese are retooling to use lead-safe glazes and are setting up their own
glaze testing facilities--which, of course, will be monitored by our own labs
on this end.
We will have to see how well it works, but it looks hopeful. A rod for the
back can be used as a staff for walking, too.
Monona Rossol
ACTS
181 Thompson St., # 23
NYC NY 10012-2586 212/777-0062
ACTSNYC@cs.com
ACTSNYC@cs.com on tue 2 may 00
> ---------- Forwarded message ----------
> Date: Fri, 28 Apr 2000 17:55:57 EDT
> From: Janet Kaiser
> Reply-To: Ceramic Arts Discussion List
> To: CLAYART@LSV.UKY.EDU
> Subject: Re: Leaching/Lemon juice story
> Resent-Subject: Re: Leaching/Lemon juice story
> ----------------------------Original message----------------------------
> Ray
SNIP>
> I am sorry, but I do not agree with "glass *is* a ceramic material". It is
> not! At least clay has been no where near any glass recipes I have seen.
For
> your information, milk bottles are made to very high specifications,
because
> they get re-used countless times and the dairies never know what people
have
> used them for... (probably just as well in some cases).
>
This is a semantic question. Its really not in the ingredients but their
state. If they are in a glassy state, they are glass--that's not too
difficult.
The best example I can think of is to explain is lava (magma) coming out of
the earth. It has relatively similar composition around the world and it
goes into making all the rocks, minerals and clays that exist through various
geological processes. It also can cool in just the right way to form
obsidian, which is a glass.
> I fail to see what there is to leach in high quality glass. Perhaps you
> could tell us?
The same as glazes--whatever is in them is slowly dissolving. That's why
laboratory glass has to be considered a source of metal ions in many tests.
It doesn't leach much, but it can be a significant problem in analyses.
SNIP
Monona Rossol
ACTS
181 Thompson St., # 23
NYC NY 10012-2586
ACTSNYC@cs.com
ACTSNYC@cs.com on tue 2 may 00
> ---------- Forwarded message ----------
> Date: Mon, 1 May 2000 14:29:39 EDT
> From: Cindy Strnad
> Reply-To: Ceramic Arts Discussion List
> To: CLAYART@LSV.UKY.EDU
> Subject: Re: Leaching/Lemon juice story
> Resent-Subject: Re: Re: Leaching/Lemon juice story
> ----------------------------Original message----------------------------
SNIP
> And farther, there are, in the USA at least, imported wares. My ceramic
> supplier tells me these are not, as a rule, tested or regulated for lead
> release. So, if this is true, your customers who gladly buy that bright,
> bright colorful glazed low-fire ware at the local department store feel
safe
> because it's sold in a store. Therefore it must be okay. How many clerks at
> Penny's get asked whether this imported bright red, glass-shiny soup bowl
> contains lead? Well, it probably does. Yet they will always ask you if your
> high-fired stoneware contains lead. People are trying to protect
themselves,
> but they simply don't know how. <
Your supplier is only half right: Its true that they are not often tested,
but they are regulated. The failure to test has to do with budget problems.
The FDA, for example, only has a budget to test around 300 shipments per year
in the New York harbors. Obviously far more than 300 shipments come in.
What they do is target shipments from countries that have a bad record with
respect to lead and test at random.
Any shipment found to leach too much lead can be seized. And this does
happen. But many bad lots get missed and get into the market. Even then, if
someone complains, the pottery can be tested, seized, and destroyed.
Even more interesting, the store selling the stuff probably will be forced to
recall the ware. This is very costly for them. They must put notices in
national papers and media and give customers refunds or replacements. Some
department stores require proof of safety of ceramic ware before they will
carry it to protect themselves from this kind of thing.
> Handmade pottery is not the only thing that can be dangerous. Glass and
> other things can also be very much so. Using our common sense is a good
> starting point, true, but people also need knowledge. We should do our very
> best to give them that. <
A few years ago a standard for lead crystal was being worked on by an ASTM
subcommittee. I was at one of the meetings. An FDA representative was
there, too. Once the standard is finished, it will probably be put into law.
Its a slow process, but it is going to happen. What seems to be a sticking
point is that it appears to be a little harder for some of the lead crystal
manufacturers to meet the same standard as ceramics.
There already are lip and rim lead and cadmium standards for glass mugs that
are the same as for ceramic mugs. You might remember that back a while ago
McDonald's give away glasses flunked these tests and had to be recalled. The
problem was not lead glass but decals that leached.
Monona Rossol
ACTS
181 Thompson St., # 23
NYC NY 10012-2586 212/777-0062
ACTSNYC@cs.com
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