4 ms·

Fundamentally I agree with you and have been doing my best to remove 20th century laboratory science experiments from my diet. I mostly don't use Teflon at all

by User23 5y ago

Fundamentally I agree with you and have been doing my best to remove 20th century laboratory science experiments from my diet. I mostly don't use Teflon at all and when I do I clean it using hot water jets instead of scrubbing it. That being said, I'm not a chemist, I was just mostly awake during undergrad chem, and I know there are fluorine compounds that are enthusiastic oxidizers[1], but some like Teflon coatings are more or less chemically inert. I assume that's because the oxidization has been taken to the point it's going to go. Is there a fluorine compound that will happily oxidize Teflon? The point of my rambling is can it be conclusively shown in controlled laboratory experiments that these compounds are completely nonreactive with the human digestive tract? [1] https://blogs.sciencemag.org/pipeline/archives/2010/02/23/things_i_wont_work_with_dioxygen_difluoride https://blogs.sciencemag.org/pipeline/archives/2010/02/23/th...

s0rce 5y ago
The manufacturing byproducts are known to be hazardous. Like PFOAs.
- medstrom 5y ago
  The manufacturing byproducts of vegetables are known to be hazardous (pesticide residue). I'll wager those PFOA are worse, but it's worth saying that if you're gonna manufacture PTFE for human consumption you could possibly clean up the process and get something perfectly clean, even cleaner than vegetables.
  - deleted 5y ago
    [deleted]
  - joshuahaglund 5y ago
    This comment makes no sense, it's like you've never heard of organic farming
    - dzhiurgis 5y ago
      It's like you never heard of parasites and bacteria on organic vegetables?
    - medstrom 5y ago
      Organic isn't pesticide-free, it just uses different pesticide formulas.
exmadscientist 5y ago
> Is there a fluorine compound that will happily oxidize Teflon? No. It can't be done. PTFE is fully oxidized (well, fluorinated). > The point of my rambling is can it be conclusively shown in controlled laboratory experiments that these compounds are completely nonreactive with the human digestive tract? I haven't looked for the study, but even if it hasn't been done, it's clear that fully fluorinated substances are not major health risks. What so many "oh no, TEFLON!!1!" people don't understand is that PTFE really is as chemically harmless as the evil chemical companies say it is. The problem is that this stuff isn't entirely PTFE (or even PFA, which is close enough even if it's oxygen in some spots instead of fluorine). Fail to fluorinate one location on that PTFE molecule and you've left a reasonably reactive pocket that can start causing trouble. (You end up with an inert PTFE chain hung off of some other molecule, which will gum up the works.) So... just fully fluorinate stuff, then? Unfortunately there's only one fully fluorinated molecule chain, and that's PTFE. Everything else, other than PTFE, is more reactive, and thus more toxic. (I guess there's also tetrafluoromethane, but that's gaseous.) And you need other things than PTFE: PTFE is chemically inert enough that it's difficult to mechanically bond to things. Other fluoropolymers are used to make bonding layers to help attach PTFE to substrates. These are what you should worry about in your cookware: they're intentionally more reactive! The other wrinkle is that I mentioned that fluoropolymers are chemically inert, because they are. But they're not thermodynamically inert. Get them hot, and they decompose into things with more reactive sites, usually in an uncontrolled way that admits some pretty nasty byproducts. (See "MTV flares" for an example of how to harness this.) Thus, the fact that PTFE pans kill birds who are sensitive to these decomposition products is real, and you should never use PTFE at high heats. Fluoropolymers are useful, good for many things, and often quite safe. But there are real dangers. Don't listen to the suits from the chemical company who insist that it's all safe, or the tinfoil hats who insist that it can never be safe. As with so many things, the truth is in between.
- ars 5y ago
  > PTFE is fully oxidized (well, fluorinated). Can't the C-C bond by oxidized? Teflon will burn if heated enough in a high oxygen atmosphere. From my understanding that's what happened to Apollo 13. (I'm not implying this will happen in a human gut :)

by User23 5y ago

s0rce 5y ago

The manufacturing byproducts are known to be hazardous. Like PFOAs.

medstrom 5y ago
The manufacturing byproducts of vegetables are known to be hazardous (pesticide residue). I'll wager those PFOA are worse, but it's worth saying that if you're gonna manufacture PTFE for human consumption you could possibly clean up the process and get something perfectly clean, even cleaner than vegetables.
- deleted 5y ago
  [deleted]
- joshuahaglund 5y ago
  This comment makes no sense, it's like you've never heard of organic farming
  - dzhiurgis 5y ago
    It's like you never heard of parasites and bacteria on organic vegetables?
  - medstrom 5y ago
    Organic isn't pesticide-free, it just uses different pesticide formulas.

exmadscientist 5y ago

> Is there a fluorine compound that will happily oxidize Teflon? No. It can't be done. PTFE is fully oxidized (well, fluorinated). > The point of my rambling is can it be conclusively shown in controlled laboratory experiments that these compounds are completely nonreactive with the human digestive tract? I haven't looked for the study, but even if it hasn't been done, it's clear that fully fluorinated substances are not major health risks. What so many "oh no, TEFLON!!1!" people don't understand is that PTFE really is as chemically harmless as the evil chemical companies say it is. The problem is that this stuff isn't entirely PTFE (or even PFA, which is close enough even if it's oxygen in some spots instead of fluorine). Fail to fluorinate one location on that PTFE molecule and you've left a reasonably reactive pocket that can start causing trouble. (You end up with an inert PTFE chain hung off of some other molecule, which will gum up the works.) So... just fully fluorinate stuff, then? Unfortunately there's only one fully fluorinated molecule chain, and that's PTFE. Everything else, other than PTFE, is more reactive, and thus more toxic. (I guess there's also tetrafluoromethane, but that's gaseous.) And you need other things than PTFE: PTFE is chemically inert enough that it's difficult to mechanically bond to things. Other fluoropolymers are used to make bonding layers to help attach PTFE to substrates. These are what you should worry about in your cookware: they're intentionally more reactive! The other wrinkle is that I mentioned that fluoropolymers are chemically inert, because they are. But they're not thermodynamically inert. Get them hot, and they decompose into things with more reactive sites, usually in an uncontrolled way that admits some pretty nasty byproducts. (See "MTV flares" for an example of how to harness this.) Thus, the fact that PTFE pans kill birds who are sensitive to these decomposition products is real, and you should never use PTFE at high heats. Fluoropolymers are useful, good for many things, and often quite safe. But there are real dangers. Don't listen to the suits from the chemical company who insist that it's all safe, or the tinfoil hats who insist that it can never be safe. As with so many things, the truth is in between.

ars 5y ago
> PTFE is fully oxidized (well, fluorinated). Can't the C-C bond by oxidized? Teflon will burn if heated enough in a high oxygen atmosphere. From my understanding that's what happened to Apollo 13. (I'm not implying this will happen in a human gut :)