How do I tell if a metal can is safe to bake in?
I normally use tin bread molds for baking. They are 'unlined', and so far, they seem to be safe enough. I suppose lining also refers to teflon coating, which is also safe for baking.

Try your luck with tin, the link below has a image for a bread mold similar to those I use.

http://www.elmaral.com/images/moldebudiningles%20graneado..jpg