It's kinda funny to say this because one of the early problems with PTFE was the nerves in the hands of people handling PTFE-insulated aircraft wiring dying - due to residues from manufacturing in the PTFE. Sure, the polymer itself is non-toxic and non-reactive as can be. Everything that went into it is absolutely not. The way to minimize that is expensive process and quality control => don't use cheap polymers!
This was also the case with agent orange. Sloppy, rushed production led to it being absolutely full of unintentional contaminants from the manufacturing process.
