Yes, I guess they safety coat them to make them shatterproof.just read in BACKYARD POULTRY, TEFLON COATED LIGHT BULBS ARE TOXIC TO CHICKENS
I assume the ones from the feed store or pet store for animals are safe.
I heard of our local zoo using bulbs from the hardware store in a bird aviary and all the birds died from the fumes of the teflon coating on the light bulbs. So you would not want to put a teflon coated light bulb into a coop!
Like I said - I try to get bulbs from the feed store or pet store.