Okay I have 4 different boxes of lamps I use for heating my brooders. One is a 100 watt flood light and the other 3 are brooder bulbs. NONE of them say Teflon on it or anything remotely, telling me that. So how do you find out? I would guess I'm would be fine since my chicks were in a plastic tote with the lamp on top of it. I think what killed OP's birds was a shatter-proof covering, which is unsafe for birds, here is an article.
http://blog.mcmurrayhatchery.com/20...nt-bulbs-a-potential-danger-to-your-chickens/
http://blog.mcmurrayhatchery.com/20...nt-bulbs-a-potential-danger-to-your-chickens/