[1] When PTFE is heated above 450 °C the pyrolysis products are different and inhalation may cause acute lung injury.

[2] Symptoms are flu-like (chills, headaches and fevers) with chest tightness and mild cough.

[3] A high white blood cell count may be seen and chest x-ray findings are usually minimal.

The polymer fumes are especially harmful to certain animals whose breathing, optimized for rapidity, allows in toxins which are excluded by human lungs.

Fumes from Teflon in very high heat are fatal to parrots,[4] as well as some other birds (PTFE toxicosis).