I was always under the impression that Teflon was such a stable molecule, even if you ingested any, it would go straight through your body without any reactions.
Incidentally, it seems that the reason to be concerned about non-stick frying pans is not the teflon, but the aluminium under the teflon coating (for details, check out the thread about aluminium cookware).
However, this article rised some doubts about the inoccuity of Teflon. Is the chemical used in the manufacturing of Teflon harmful only to employees making it, or to anyone using Teflon frying pans?
According to this 2001 article , there are concerns that teflon, when heated, can degrade into other compounds, one thought toxic to plants, while another accumulates in animal (and human) tissue.
Sounds like the debate’s only just heating up on this one.
It probably too soon to tell whether the perfluorooctanoic acid released by teflon is a significant danger. Here’s a bit on the EPA’s response: Teflon chemical draws EPA’s attention (4/15/03)
As for Teflon itself, it’s so tightly bound to itself, so to speak, that it doesn’t have any use for binding to your scrambled eggs, burned on cheese, or your insides.
That is exactly what we are trying to quantify for NASA in one of our research projects.
NASA uses Teflon® insulation on electrical wires and hence a overheating/shortcircuiting of these wires give rise to products which are more harmful in the enclosed space in a shuttle. Its complicated by microgravity and flame properties.
However, I seriously doubt if the regular fluorocarbons give substantial degradation products in home cooking coatings, but I will look into that.
I don’t have ready references at home, but would be happy to provide more info if required.