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need advice from glaze toxicity gurus, please

updated thu 4 jul 02


Jeremy McLeod on mon 1 jul 02

Had the pleasure recently of seeing some work fumed with stannous chloride (flouride? my
non-techie brain sometime glytches). Great "art nouveau-ish" rainbow spectral effects.
Just 'cuz the fume's will kill 'ya? At some point I'm inclined to solve the safety issues
and begin exploring using this stuff.

So, here's the question... the work I saw was represented as "food safe" so long as the
ware that had been fumed was originally glazed with something that is food safe.

After the fumes have dissipated and that level of toxicity has passed,
what is folks experience with the potential toxicity of ware that has been fumed
with stannous chloride? Tin cups have a long history of use. Is the tin fumed onto
ceramic ware worth the risk for use with food? or should one stick to non-functional
work with the wondrous potentials of this kind of fuming?

Thanks in advance for the list's collective wisdom.

Jeremy McLeod

Ron Roy on tue 2 jul 02

Hi Jeremy,

I don't see how any metals deposited on the surface of ware will not be
affected by food.

If the "metal" is Tin the latest info I have indicates it is not a problem
when ingested - however it will eroded away when it is in contact with food
as the layer is only one or two molecules thick.

There are many other "metals" which are toxic and should not be used in
this way on functional ware.

I would say keep them off surfaces which will come in contact with food or lips.

I have no idea how they will stand up to repeated dish washing - I would
think not very well but you can test for that.


>So, here's the question... the work I saw was represented as "food safe"
>so long as the
>ware that had been fumed was originally glazed with something that is food

Ron Roy
15084 Little Lake Road
Brighton, Ontario
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513

iandol on wed 3 jul 02

Dear Jeremy McLeod <>

I think you will have to look through the literature for anything =
difinitive about the toxicity of Tin compounds. Tin, as a metal was used =
to line preserving cans because of its corrosion resistance, but I =
suspect any metallic chlorides, inhaled as a vapour may cause tissue =

However, there is another issue, relating to the durability of a fumed =
lustre surface. Since this material will sit on the surface of the glaze =
rather than sink into the subsurface layers it will be removed by =
abrasion and may be susceptible to the corrosive effects of hot =
detergent solutions. This is a problem which plagues industrial =
products. Dip-Ing Annette Lucas of W.C Heraeus GmbH and Co. KG, is =
developing lustres which will be incorporated into the glaze rather than =
being a surface effect. But production temperatures will be much higher.

Best regards,

Ivor Lewis. Redhill, South Australia