PTFE is considered a PFOAs molecule by ROHS3 and you can’t use it in new design. I know this because I design stuff that occasionally may need high temperature plastics or other solids. The stuff is inert but its not good for you as the other commenter mentioned. Once heated to 500F or 260C, it may release toxic fumes that can cause flu-like symptoms, liver damage, cancer and disruption in development of kids.