When these lab rats breathe in fumes from overheated non-stick coating at a certain level, their lungs get inflamed really quickly — within just 4 hours — and lots of immune cells rush into the lungs, showing their bodies are reacting strongly.

What we've found so far is that the evidence we've reviewed leans toward PTFE fumes causing increased inflammation in the lungs of rats. Our analysis of the available research shows this effect happens quickly after exposure. We looked at two assertions from the data, and both support the idea that when rats inhale fumes from overheated non-stick coatings, their lungs respond with signs of inflammation. In one case, we found that rats developed lung inflammation within just 4 hours of exposure, with a noticeable influx of immune cells — a clear sign the body is reacting to a threat [1]. In the second case, we saw a rapid rise in inflammation signals in the lungs, also within a few hours of exposure [2]. These signals suggest the body’s immune system is activating in response to the fumes. The evidence we've reviewed comes entirely from studies on lab rats, and all of it points in the same direction: PTFE fumes from overheated coatings are linked with lung inflammation in these animals. There were no studies in our analysis that contradicted this finding. Still, what we know is limited to these animal studies and specific exposure conditions. We cannot say how this might apply to humans or what happens with long-term or low-level exposure. Our current analysis only reflects what has been observed in rats under controlled lab settings. Practical takeaway: If you're heating non-stick cookware at very high temperatures, especially beyond what it's designed for, fumes are released that have been linked with lung inflammation in rats. Based on what we've seen so far, avoiding overheating these materials seems like a reasonable precaution.