Bullshit. There is “toxic” and there is “causes cancer, even outside California, reduces fertility, and negatively affects fetal development.” Just because something doesn’t kill you immediately does not mean it isn’t harmful.
Even inert materials can do stuff, such as prevent other reactions or act catalytically or have physical impacts (collision which defold molecules, make certain things heavier by being enclosed or enclosing ... ).
Furthermore PTFE is know to interact with Gallic Acid [1] somewhat. The body contains gallic acid
I really appreciate you making the effort to debunk the witch-burners; have you thought about doing it in a less ephemeral medium? Your comment will probably be here for a decade or more but nobody will read it after this month.
But the claim in question is one of the best-known and most thoroughly established claims in all of toxicology. Asking for scientific research supporting the biocompatibility of PTFE is akin to asking for scientific research supporting biological evolution or the claim that people have landed on the moon: it's a sure sign that the person making the demand has a pre-existing flimsy pretext for rejecting literally all the research in the relevant field, which did indeed turn out to be the case; see https://news.ycombinator.com/item?id=32517203.
And you think that ingesting PTFE is somehow worse than an actual PTFE implant? Why you insisting it must be a digestion study? Do you make such requirements for everything you interact with? Has someone done a study on using paper straws? Or plastic plates? Or metal spoons?
Do you understand that when you eat PTFE it comes out exactly the same way it went in?
Even powerful acids can't do anything to PTFE, what makes you think the body can do anything to it?
Titanium is a common biocompatible implant material, widely considered safe in this context. One of the primary benefits of titanium implants is that that they readily form a TiO2 passivation layer. TiO2 is also common in many topical lotions and sunscreen, where it is considered safe.
TiO2 also has a signficant body of evidence demonstrating that it is a carcinogen when inhaled in particulate form. Just because some compound is safe in one context does NOT mean it is safe in all contexts.
> Do you understand that when you eat PTFE it comes out exactly the same way it went in?
I bet if I asked you to eat shards of glass, they would leave your body pretty close to how they went in :) Whether your body would remain unchanged is another question. While this is an extreme example, there are more subtle ways a compound could interact with the body. For instance, glyphosate has long been considered a safe compound because it "leaves the body the way it comes in." However, recent research has revealed substantial evidence that glyphosate may adversely interact with the human microbiome, which is linked to many various health conditions. This is an active thrust of a lot of new medical research that wasn't strongly considered 20 years ago. It is simply not enough to say the compound remains unchanged, the real question is whether the body is unchanged, and the body is pretty complex and our understanding is very incomplete.
It's not clear which version of the scientific method you subscribe to from your posts, but in general proving a negative is ~really, really~ hard. This list of all possible interactions in the human body with arbitrary chemicals is quite long. The list of things that have been 'proven safe' only to be considered unsafe when studied more carefully is quite long. To suggest that our knowlegde of the safety of ~any~ compound is complete is impossible.
> And you think that ingesting PTFE is somehow worse than an actual PTFE implant?
I think that it isn't even close to being equivalent.
> Why you insisting it must be a digestion study
You are the one who made the statement: "It's about the most inert material that you can possibly ingest." so prove it, or admit that this is your opinion and not backed by research.
I'm not even asking for research comparing the effects of the ingestion of PTFE with every other "material that you could possibly ingest", just for any data, at all, on the long term effects of ingesting PTFE.
It's my understanding that the toxicity of ingested PTFE is still an open question, that there is no consensus on the safety or dangers of Teflon in food, and no research into the effects of ingesting it over/after long periods of time (say > 20 years).
If you have actual knowledge of advancements in the science I'd like to see what was found, but otherwise let's just acknowledge that there is still far too much work to be done before we can make meaningful claims about the safety of ingesting PTFE. At best, what we can say right now is that it won't instantly kill you, but the long term effects of ingesting PTFE on the body are unknown.