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use of cadmium and lead (was: red glaze for raku)

updated mon 30 sep 02

 

Janet Kaiser on mon 30 sep 02


Craft Potters Association of Britain declaration:

"The Craft Potters Association is fully aware of the possible danger to
health of cadmium or lead released from glazed pottery into food. The CPA
Council requires all members sending work to the shop to state whether lead
or cadmium are used in their pottery or not. It these materials are present
then potters must have their work tested regularly and produced
certificates to show that it conforms to the new British Standard BS6748.
The public can buy safely from the CPA shop"

So what exactly is the BS6748? Apparently similar to ISO6486. I tried
looking up the British Standard but would have to pay =A311 sterling... It
is headed: BS 6748:1986 Specification for limits of metal release from
ceramic ware, glassware, glass ceramic ware and vitreous enamel ware. As it
was 1986, I wonder how the CPA can say the "new" British Standard?

What is good enough for the CPA is good enough for The CoA and we take the
same line. Note that this does not exclude the use of either. As long as a
glaze is stable and does not leach, it will pass the test. I believe the
health and safety people from the local council use acid (sulphuric?) when
testing and they do test everyone. They buy a pot off the maker and then
take it away to do nasty things to it... Heaven help you if the pot fails.
You get closed down and may even be prosecuted.

The big scare about cadmium and lead has been because of poor glaze
technology, which we just did not take seriously in the past, but which no
one can deny is extremely important these days. Just one more reason I get
really mad at colleges and art schools for not teaching this important part
of responsible craftsmanship.

Sincerely

Janet Kaiser - who (it is claimed) poisoned a friend through a Raku tea
bowl which had an "unstable" lead glaze but looked absolutely gorgeous!
Lovely flashing... The friend is still alive, but HIV positive. No, that
had nothing to do with the tea bowl.

Janet Kaiser

The Chapel of Art =95 Capel Celfyddyd
8 Marine Crescent, Criccieth LL52 0EA, Wales, UK
Tel: 01766-523570 URL: http://www.the-coa.org.uk