Veritasium had video explaining about PFAS and environment protections that were needed to keep people/animals from being sick. Somewhere around minute 23 in video.

https://www.youtube.com/watch?v=SC2eSujzrUY

▲ JumpCrisscross a day ago | parent | next [-]

Minute Earth has one that’s more concise: https://youtu.be/H3aFzQdWQTg

▲ contrarian1234 21 hours ago | parent | prev [-]

What a muddled video

For the first half he seems to constantly mix up C8 and Teflon. After a long section explaining that C8 is some carrier molecule used to make Teflon - he then explain C8 is used in factories and kills cows. But it's not clear C8 is anywhere other than the factory and the town around it

They then extrapolate from two chemical (C8 and C6) to just anything that remotely similar (PFAS)

Later they walk it back and say it's only a few chemicals. Actually your Teflon pan is safe. But then say thing "Blah blah was used to make waterproof..." is it in the final product? or is it part of the chemical procedure to make the product?

Is the problem the final consumer goods? Or is the problem the chemical manufacturing? (and subsequent dumping in the environment) Is this residue from after making the Teflon-like material?

The last parts I couldn't follow at all b/c it was a acronym soup of a ton of chemicals that aren't really explained. At this point I'd lost all faith in the presenters impartiality. Seems like he's just trying to stoke outrage for engagement

(the central point may still be right!)

▲ ganyu 20 hours ago | parent | next [-]

PFAS is short for 'Per- and poly- FluoroAlkyl Substances'. The Teflon that's used on your pans, which are 'poly-' materials, comes in extra long chains (hundreds of thousands of molecules). Most of its chemical bonds are hidden behind the extremely reactive Fluoride atoms (so if Fluoride is bonded onto that position, it's hard to take it off) and are extremely inert, so they don't interfere with typical biological reactions, thus are perfectly safe.

C8 is known as PFOA (perfluorooctanoic acid). Per for its chained molecule shape (no carbon side chains), 'fluoro' for the F part, 'octanoic' for the 8 carbon atoms, and 'acid' for its chemical property. Unlike Teflon:

  - C8 has a really small molecular mass, making it easier to flow around your body participating in all kinds of biological operations;
  - It is an acid (having the carboxylic '-COOH' group) and can pretend to be all kinds of acids and actively take part in reactions. Once they start to get inside, the consequences can be unpredictable and devastating.
  - All other atoms on C8 except for the last -COOH group are covered by fluoride atoms. This means that C8 is not biodegradable (no enzyme can break apart the C-F covalent bond since it's bond energy is really too high), and when it gets into the environment, it stays that way.

C6 has a highly similar chemical property akin to C8 (it's a carboxylic acid, and has all atoms covered by fluoride), so is equally harmful.

	▲	contrarian1234 6 hours ago \| parent [-]
		I'm not sure why you're summarizing what's explained in the video. It's clear PFAS contains chemicals that are likely dangerous (like C8) and chemicals that are likely not - like Teflon. So, unless I'm misunderstanding, as an umbrella term for dangerous chemicals it's useless from the get go. I understand the potential danger of C8 and similar acids.. it's explained in detail. But the part that's not explained is why is it in final consumer products. It seems like a chemical that only forms a step in the processes of making Teflon (and I'm guessing other similar products). Is the problem they were just dumping it into the soil at the plant? How is it getting to polar bears? (they keep talking about polar bears)

▲ ganyu 20 hours ago | parent | prev | next [-]

So TL;DR,

1. Any substance that has most atoms covered by Fluoride are 'PFAS'. 2. C8 is strictly speaking PFOA (by-definition). 3. C6, and all other acids that has similar chemical properties to C8, can all be generically classified as PFOA-like materials. But for ease of communication people also call them PFOAs or just short for PFOA.

4. PFOAs are crucial for manufacturing Teflon. 5. The problem is manufacturers just dump waste water from PFAS production plants (containing PFOA) without post-processing into natural water bodies and let these toxic substances participate in the food chain and eventually land in our own bodies.

	▲	contrarian1234 6 hours ago \| parent [-]
		So the problem isn't PFAS or Teflon. It's the dumping of intermediary chemicals during manufacturing? This is the part that just comes off as fear mongering How is the PFOA ending up in food? Is it from contaminated groundwater near the plant? Isn't the solution to not consumer agricultural products from that limited area? And.. how is it ending up in polar bears? The video just seems sensationalist. Somme chemical use in a step to make teflon is pretty toxic.. big surprise. But then it's ending up everywhere... somehow? And it's never really explained. But lots of hangwringing

▲ jackmottatx 21 hours ago | parent | prev [-]

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