It's releasing a high amount of micro and nano plastics, and those are linked to different health issues including cancer.
https://www.sciencedirect.com/science/article/pii/S0048969724027232
our findings suggest that PTFE-MPs-associated toxicity may be specifically linked to the activation of the ERK pathway, which ultimately induces oxidative stress and inflammation.

https://www.nature.com/articles/s41698-024-00554-5
https://pmc.ncbi.nlm.nih.gov/articles/PMC7027163/
https://biologyinsights.com/oxidative-stress-and-cancer-whats-the-connection/
https://biosignaling.biomedcentral.com/articles/10.1186/s12964-023-01398-5
https://pmc.ncbi.nlm.nih.gov/articles/PMC6831096/