We are going to be painting our home with homemade clay paints, using clay, water, sand and hardeners such as wheat paste.. and ceramic dyes used in glazes for pottery for the stains. Many of these are derived from Iron Oxide which I'm assuming is safe.
However others are derived from the following metals:
Al - Aluminum Oxide
B - Boric Oxide
Ca - Calcium Oxide
Cd - Cadmium
Co - Cobalt Oxide
Cr - Chromium Oxide
Fe - Iron Oxide
Mn - Mangenese Dioxide
Ni - Nickel Oxide
Pr - Praseodymium Oxide
Se - Selenium
Sb - Antimony Oxide
Si - Silicone Dioxide
Sn - Tin Dioxide
Ti - Titanium Dioxide
V - Vanadium Pentoxide
Zn - Zinc Oxide
Zr - Zirconium Dioxide
However, the context is they're assuming that you're gonna use these in glazes for pottery. Presumably, having this stuff on the walls will lead to more dust/inhalation potential of these and I just wanted to see if any of you have experience with this or know whether it's advisable to use all of these.
I would recommend you stay away from the heavy metals (cobalt, Cadmium, Chromium, Selenium, Praseodymium, Zirconium and Vanadium.
As you noted, the original intent is for a Fired product, which encapsulates or otherwise renders the heavy metals more inert than using them as a raw coloring agent.
Some of these elements we can recognize as beneficial on occasion but it has a lot to do with quantity and delivery method (usually as small dose vitamins or multi mineral supplements).
Inhalation and skin contact absorption might not be good for human health and even poisonous.
What if your coating flakes or otherwise manages to contaminate food stuffs? Cobalt and the other heavy metals are detrimental to good human health.
If you are serious about using any of the listed metal compounds, it would be wise to contact an MD or poison control center for information first.