"PTFE" Nonstick Surface

The non-stick surface known popularly by its trade name as "Teflon" was devised by DuPont.  Its fundamental ingredient is the molecule polytetrafluorethylene, commonly referred to as "PTFE."  Fluorine is the critical atom in the molecule.  Of all the atoms, fluorine holds its electrons the tightest.  Because of that, it will not bond easily with other substances.  

A molecule of PTFE has four fluorine atoms.  Since the fluorine atoms will not bond readily with other substances, PTFE is very non-stick.  In a sense, it repels other substances.   That is why oil beads on non-stick surfaces.  PTFE is inert; it typically does not react with other substances.  Thus, usually nothing will stick to it.  Moreover, if ingested by a human, it will pass through the body without being absorbed into it.

However, because PTFE is really a type of plastic, if heated above 530° F, the molecule becomes unstable and will begin to react with other substances, and undue heat will cause it to deteriorate.  You should not use a pan if its PTFE surface has been ruined by excessive heat.