“I think what Whitney was expressing was the fact that most chemicals used in ceramics are “cancer causing” BEFORE they are fired”¦raw form. ”
This is just not the case.
To suggest it is irresponsible.
Whereas it’s undeniable that nutmegs and almonds are toxic. As are red beans and potatoes, if improperly treated. We can kill ourselves by overdosing on coffee.

We have to get this into perspective. The basic materials of ceramics are found in our everyday surroundings, humans have been firing clay for at least eighteen thousand years.
We don’t need to use particularly toxic, reactive, carcinigenic materials to make pots, but if we choose to, then we can use POTENTIALLY dangerous materials in safe ways.
As for fumes from firing clay, well, sure, the fuel used to fire the clay may cause fumes that are harmful. But five minutes worth of the fumes released earlier this year by the Eyjafjallajokull eruption in Iceland would be more harmful than all the kilns fired in the last decade.

If you want to see toxic, carcinogenic, environmentally damaging activities, you just can’t beat mother nature,

I think there is blur between “eco friendly” and “human friendly”. Eco friendly would be to pollute the environment, for example, when you fire ANY ceramic piece, it’s polluting the air, toxic fumes are released from wares whether you dig the clay up in your backyard or not. The components of clay change when heated at a high temperature and create fumes…BUT the same piece, by the time it’s fired, may be ‘human friendly’ and non-toxic. So which is it? It falls into both categories with varying degrees of toxicity on either side.

Higher fired (stoneware and porcelain) pottery tends to use less-toxic glaze materials. Bright colours at earthenware temperatures,such as red yellow and orange tend to use toxic compounds.

Wood-fired kilns are carbon-neutral, whereas electric or gas kilns tend to be fired by fossil fuels.

The factory where i work actually a few years ago invested on Spectometer of Light Absorption to check on Lead and cadmium on our wares.

We have two body clays… the “regular” earthenware, which the flux(?) is Calcium Carbonate, so its has a porosity of 14 %, LOI 11% and another body clay, that considering our temeperatures, it’s still earthenware, though the flux is feldspar, higher mechanical strenght, LOI 5 % and a slightly lower porosity than the calcium carbonte one.

All this to say i am familiar to the lead and cadmium limits specially in USA……and particular in California’s DA Proposition 69, which in my opinion are an exageration without the chemical/health study to really back it up those values.

We (mostly all ceramics in Portugal that do tableware) don’t use Lead glazes anymore….only on decoration or underglaze. We actually had Wedgwood as clients like 15 years ago, and they pretty much made us jump to a more “green”.

* We have the Continuous Tunnel Kiln (max temperature is 1050 ºC or 1922 F) works on natural gas.

* As already stated our opaque and transparent glazes don’t have Lead at all.

* We use stable pigments…the raw oxides are seldom used…the only one used is perhaps Iron Oxide red, Cobalt oxide…..and its rare.

*We, by portuguese law, must have a Water residual treatment station, the residue that comes out goes to a cement factory (along with the old plaster molds)….they use it on their cements formula. Unfortunatly the residue has glazes and clay mixed….and the experiences to use it on the body clay werent successful.

* The so called EcoDesign. Our Designer pretty much gives the same dimension to the wares: for example, you may have 2 different clients which their wares of course have different designs BUT the dimension is the same…both clients, the big plate is 32 cms diameter,,,,and desert plate is for example 12 cms diameter. Why?. Packing! That way the boxes will also be around the same size…and can be re-used on the several different clients…Thus making us buy less boxes.

*and a lot more………

Also annoyed about the arguments where people bring in driving their car as part of the art making process, really, do you drive to the grocery store to buy food and call that green too because you are using recyclable bags? I live in California, a few years back we were in a power crisis, so is that why here and now we should supposedly be thinking green, but it was just 50 years ago there were more than 3 h-bombs dropped on the planet so now we care? There are other art forms that ingest more energy than a gas kiln. (molten glass production)

I do know older ceramics like Bauer, those lovely strong oranges and yellows not only contain lead but uranium. A geiger counter will activate when near them. Of course, so will smoke alarms, but that’s another story….

Older ceramics with wear or hairline cracks on glaze surface may also leach lead when lemon juice or salad dressings are served on those plates.
My favorite old vintage ironstone tests lead positive so I’ve given up using them for food.