I am sure there are still kilns being fired in unvented classrooms and the
teachers think it just smells bad,
but is not harmful. Headaches would be one of the first symptoms that you
are getting poisoned.
Madera High School
>Be careful as well breathing in fumes from the bisque firing. This firing
>emits dangerous toxins as well. Studio Potter Magazine some years back had
>information on this and through this article I was able to discern that I
>had carbon monoxide poisoning through the bisque firing. My kiln was in my
>classroom. (perhaps it was carbon dioxide poisioning, regardless I was
>almost incapicated and took a while for recovery).