> Abstract: Japanese quail and parakeets were exposed to the pyrolysis products of: (1) commercial fry pans coated with Teflon® finish, (2) plastic fry pan handles, (3) corn oil, and (4) butter. Other materials used in the test were commercial aluminum fry pans and cast iron fry pans. A four-hour Approximate Lethal Temperature (ALT) was determined for each test material for each specie. All products tested were lethal to Japanese quail with ALT's ranging from 260° C for butter in cast iron to 370 °C for a plastic handle in a glass container. The ALT for a fry pan coated with Teflon® finish was 330°C. All products were also lethal to parakeets with ALT's of 260°C for both the pan coated with Teflon® finish plus butter and the cast iron pan plus butter. The ALT for a fry pan coated with Teflon® finish was 280°C.
Butter in cast iron is toxic at 260 degrees. Teflon isn't toxic until 280 degrees.
Check out http://www.ncbi.nlm.nih.gov/pubmed/4723395
> Abstract: Japanese quail and parakeets were exposed to the pyrolysis products of: (1) commercial fry pans coated with Teflon® finish, (2) plastic fry pan handles, (3) corn oil, and (4) butter. Other materials used in the test were commercial aluminum fry pans and cast iron fry pans. A four-hour Approximate Lethal Temperature (ALT) was determined for each test material for each specie. All products tested were lethal to Japanese quail with ALT's ranging from 260° C for butter in cast iron to 370 °C for a plastic handle in a glass container. The ALT for a fry pan coated with Teflon® finish was 330°C. All products were also lethal to parakeets with ALT's of 260°C for both the pan coated with Teflon® finish plus butter and the cast iron pan plus butter. The ALT for a fry pan coated with Teflon® finish was 280°C.