Fascinating. Luckily butter almost never gets to those temperatures. We're obviously different animals, and it seems that birds can eat butter, so I wonder what it is about oils specifically that kills them. Likely the mechanism will be different from PTFE and PFOA and maybe incompatible with humans who also suffer from large-scale inhalation (see article). We don't know much about long term PTFE/PFOA inhalation in small quantities.
So it seems to be that cast iron itself, heated, doesn't cause the bird to die. Cast iron + butter kills the bird, but so does teflon + butter. So in butter-less dry pan to dry pan scenarios, cast iron is non-toxic yet teflon is toxic.
As you can see here [1] if you leave your pan on the stove heated it can hit these toxic temperatures within minutes. So the exposure to the gas isn't hypothetical. Dry pan toxicity is a real concern which is unique to Teflon.
Then there's digesting it since it will slowly wear off into your food. We don't have science specifically looking at long-term slow exposure to PTFE/PFOA. So you're taking your chances... but we do know that PFOA is much less inert than PFTE when digested.
Non-stick pans won't last as long as cast iron or stainless steel, and cast iron can perform like non-stick while also adding flavor and necessary iron. Oh and cast iron can be often as cheap or cheaper than non-stick (except for the super crazy low end, but talk about most likely to be toxic...), and most certainly is cheaper in the long run (I'll have my great-grandmother's pan for the rest of my life which I do 90% of my cooking in... try that with your teflon).
So if you don't need non-stick pans, so why voluntarily expose yourself to the risk?
So it seems to be that cast iron itself, heated, doesn't cause the bird to die. Cast iron + butter kills the bird, but so does teflon + butter. So in butter-less dry pan to dry pan scenarios, cast iron is non-toxic yet teflon is toxic.
As you can see here [1] if you leave your pan on the stove heated it can hit these toxic temperatures within minutes. So the exposure to the gas isn't hypothetical. Dry pan toxicity is a real concern which is unique to Teflon.
Then there's digesting it since it will slowly wear off into your food. We don't have science specifically looking at long-term slow exposure to PTFE/PFOA. So you're taking your chances... but we do know that PFOA is much less inert than PFTE when digested.
Non-stick pans won't last as long as cast iron or stainless steel, and cast iron can perform like non-stick while also adding flavor and necessary iron. Oh and cast iron can be often as cheap or cheaper than non-stick (except for the super crazy low end, but talk about most likely to be toxic...), and most certainly is cheaper in the long run (I'll have my great-grandmother's pan for the rest of my life which I do 90% of my cooking in... try that with your teflon).
So if you don't need non-stick pans, so why voluntarily expose yourself to the risk?
[1] http://buffalobirdnerd.com/clients/8963/documents/Teflon.pdf