It is commendable that you are seeking a safe environment for
your ceramics classes. I write a safety column for the Art
Educators of New Jersey(AENJ) and have found over the years,
that what the art suppliers often indicate on their labels as
being safe is not quite true. One must read the sheets (MSDS)
that should be supplied with each item ordered. The Material
Safety Data Sheets (MSDS) informed me that the many glazes that
were labeled as being safe actually contained fritted lead which
is a toxin. I never permit the students to create any pottery
item that will be used as a food container. I am unable to
control the many variables when firing that may not cause the
kiln to fire unevenly and safely: power surges, hot and cold
spots in the kiln, and quality control. Nor am I able to test
the completed projects for their actual level of lead. Many
suppliers are now providing proper labels to adhere to purchased
art supplies that are used in your classroom. In most cases the
labels on a product do not give s