Jane is right. Even at the college level I use Crayola and other
safe projects as much as possible.
Students are advised about dangers of clay dust and I don't use
clays that contain talc.
For the painting courses I explain about toxic materials in
professional paints (cadmiums, etc). Of course we don't even have
the bright white lead based paints I remember from the early days.
I pay attention to fumes and don't allow paint pens, metallic paints
in the classroom but in other well ventillated areas. Both latex and
non-latex gloves are available.
I run the kiln when students are not in the room, even though it has
the latest safety vent and other features. I never let the kiln stop
automatically and have sometimes stayed at the school until midnight
to be sure the electricity source as well as the kiln is shut off.
We art teachers have a lot of responsibility for health and safety
in our schools!