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Another example people miss is plumber's tape. That tape is effectively all PTFE. Literary every plumbing system in the last 20 years or more has all your wate

Another example people miss is plumber's tape. That tape is effectively all PTFE. Literary every plumbing system in the last 20 years or more has all your water inlets lathered in PTFE along every joint of the pipework.

hef19898 4y ago
Which, as bad as it is in general, shouldn't be that much of a problem since it is not in direct contact with water flow, being used to seal the joints.
- serf 4y ago
  > Which, as bad as it is in general, shouldn't be that much of a problem since it is not in direct contact with water flow, being used to seal the joints. have you ever taken apart half of those joints? people love going overboard with the tape, when the threads are overloaded guess where the excess gets squished?
- amelius 4y ago
  Since the tape prevents leakage, isn't it in contact with the water flow by definition?
  - 8note 4y ago
    Kinda. Water has a skin effect where at the surface it doesn't move, only acts as a lubricant of sorts for water in the middle of the pipe
    - amelius 4y ago
      Interesting. What does that mean for the diffusion of contaminants? Does the boundary between these two regions act as a barrier for diffusion?
aaaaaaaaaaab 4y ago
Just use crimped fittings or hemp.
- nousermane 4y ago
  Or copper pipes soldered with lead-free/SAC. Those are rather pricey though.
  - kube-system 4y ago
    Fun fact: Between 1986 and 2011, lead free plumbing can contain up to 8% lead per EPA standards. After 2011, lead free plumbing may now only contain 0.25% lead.
  - zionic 4y ago
    For copper you want to use ProPress, it’s completely solderless
- fuzzfactor 4y ago
  >hemp Incidentally, before Teflon tape became affordable enough for plumbing use, most plumbers were using a type of traditional "pipe dope" instead. Maybe this is another application where it might be a feature if "dope sells itself".
  - aaaaaaaaaaab 4y ago
    No, I’m talking about literal hemp fibers: https://youtu.be/QJAIFJtiRQo https://youtu.be/QJAIFJtiRQo That’s the traditional way of sealing joints. No chemicals, just hemp and your own saliva (you usually don’t have running water nearby when doing plumbing).
    - bohwaz 4y ago
      This is banned in Europe as bacteria develop with time, making it unsafe for drinking water pipes. Sometimes chemicals are safer.
zbrozek 4y ago
Is that one so bad in its end use? I would imagine production byproducts would be the bigger issue for plumbing tape, which is effectively solid and used in non-abrasive applications.
- fuzzfactor 4y ago
  The PTFE itself is really an inert polymer that is harmless to the water flowing through. It will not get into your water or break down through decay, those were considered superior properties. It takes a lot more heat to decompose PTFE than it does regular plastics, but once that's happening the vapors are a lot more toxic. But these are not the kind of plumbing fittings for welding or soldering. Chemically, ethylene is the gaseous hydrocarbon monomer that is polymerized to make the common polyethylene plastic, like so many milk jugs and other items needing a cheap plastic are made of. Tetrafluoroethylene (TFE) is the fluorocarbon monomer which is the fluorinated analog of the common ethylene. It's really rough and wants to spontaneously react with itself (or any number of other things) to form a bit of polytetrafluoroethylene (PTFE) polymer with somewhat explosive force under not-fully-predictable conditions. So nobody really wants to handle TFE. Instead extensive research at places like 3M and DuPont came up with a number of different alternative starting molecules that were less self-reactive but could still be coerced into forming PTFE as a final product. The PTFE was intended be a forever plastic like no other, but a variety of fluorinated starting materials and byproducts were also obtained some of which had interesting properties themselves. For instance some acidic PFAS compounds are not very inert on their own, one end of the molecule will firmly bond to some natural products like canvas or leather, which largely neutralizes their further reactivity. So after that those molecules aren't going anywhere until degradation of the substrate occurs. And the other end of the molcules possess the perfluorinated inert feature, forming an invisible coating which repels water like people had never seen. So it's all this other stuff, and the final degradation products (of those PFAS that have a decomposition pathway), that ends up in the environent eventually, many with a physical propery of self-dispersal. OTOH the PTFE is a solid plastic and just sits there permanently inert, no decomposition pathway, with little tendency for further environmental spread unless incinerated or microscopically pulverized, which disperses it as a byproduct gas, or very tough microplastic, respectively.
deleted 4y ago
[deleted]
bandyaboot 4y ago
I could be mistaken but I believe PEX has been the dominant type of pipe used in new water systems over the last 15 years or so. There’s not really any plumbers tape involved with the various types of fittings that are used with those pipes.
- mh- 4y ago
  Connecting the pipes, no. but connecting fixtures to those pipes, yes. Showerheads, faucets, etc. will all be screwed on and sealed with PTFE.
  - bonzini 4y ago
    I have seen plumbers that are still using hemp.
    - DoingIsLearning 4y ago
      That's exactly what I did with all my faucets. Call me paranoid but I've taken them apart remove all the mangled PTFE tape and sealed the thread with hemp.
jefftk 4y ago
That's not correct. Neither PEX nor copper use tape, and that's been the vast majority of new water piping for 20+ years. In connections that do use tape, like old galvanized steel pipe, the tape is entirely within the joints, because it's a lubricant. (Just checked with my uncle who's a plumber)
- kube-system 4y ago
  Yeah, there is generally no PTFE in the middle of anyone's PEX or copper system. Thread sealant only goes on threads, and PEX systems are crimped together and copper systems are (generally) soldered together. Threaded fittings are expensive and so they're avoided when possible. But, either system will have often have PTFE at any terminations where transitioning to other fixtures via threaded fittings. [0] And occasionally there are brass fittings in the middle of these systems which are threaded and those will use PTFE as well. [0]: https://terrylove.com/images/homeowner/lee_01.jpg https://terrylove.com/images/homeowner/lee_01.jpg
- zionic 4y ago
  >PEX Yeah, rather than just the joints now the entire pipe is leeching toxic compounds
  - jefftk 4y ago
    What does PEX leech?
    - aquaduck 4y ago
      My understanding is that polyethylene is one of the most benign plastics with respect to leaching, and that PEX should be even more benign than normal polyethylene because of the crosslinking.
stjohnswarts 4y ago
can you point me at an authoritative source that says PTFE is bad and not inert in humans (unless you reach a temperature of 500F or so)? All I ever see are "holistic medicine" and food babe level sites saying it.
refurb 4y ago
You realize we implant PTFE into human bodies as medical implants? What makes you so concerned about PTFE tape on a tap?
- DoingIsLearning 4y ago
  The FDA retroactively banned PFOA residue from PTFE coated stents and guidewires. So you would have had people with PFOA contamination during endivascular surgery prior to that. PFOA-free PTFE guidewires suffer higher risk of delamination, i.e. flaking of the ptfe coating which becone an embulus in your bloodstream. The FDA does an amazing job at keeping us safe but the more evidence we have about the effects of novel substances the more I am biased to applying a cautionary principle. In my pipe fixtures at home I will stick to hemp to seal the threads. If in the future I happen to need a stent, then I'll worry about it when I cross that bridge. :)
  - refurb 4y ago
    Why do you assume that hemp is safe?
    - DoingIsLearning 4y ago
      Hemp is being used by Humans since the Neolithic, we have been eating, wearing, and building houses with it for more than 10 centuries. If it really was unsafe the data would have revealed it a long time ago. Synthesized fluoropolymers have been around for about 60 years with an overall poor track record for Health and Safety. If we apply a moderate cautionary principle towards novelty and also consider the minor life quality improvements that these 3M innovations bring (fluoropolymers only make things slightly less incovenient they are not ground breaking in my life), then it really is a no brainer decision.

hef19898 4y ago

Which, as bad as it is in general, shouldn't be that much of a problem since it is not in direct contact with water flow, being used to seal the joints.

serf 4y ago
> Which, as bad as it is in general, shouldn't be that much of a problem since it is not in direct contact with water flow, being used to seal the joints. have you ever taken apart half of those joints? people love going overboard with the tape, when the threads are overloaded guess where the excess gets squished?
amelius 4y ago
Since the tape prevents leakage, isn't it in contact with the water flow by definition?
- 8note 4y ago
  Kinda. Water has a skin effect where at the surface it doesn't move, only acts as a lubricant of sorts for water in the middle of the pipe
  - amelius 4y ago
    Interesting. What does that mean for the diffusion of contaminants? Does the boundary between these two regions act as a barrier for diffusion?

aaaaaaaaaaab 4y ago

Just use crimped fittings or hemp.

nousermane 4y ago
Or copper pipes soldered with lead-free/SAC. Those are rather pricey though.
- kube-system 4y ago
  Fun fact: Between 1986 and 2011, lead free plumbing can contain up to 8% lead per EPA standards. After 2011, lead free plumbing may now only contain 0.25% lead.
- zionic 4y ago
  For copper you want to use ProPress, it’s completely solderless
fuzzfactor 4y ago
>hemp Incidentally, before Teflon tape became affordable enough for plumbing use, most plumbers were using a type of traditional "pipe dope" instead. Maybe this is another application where it might be a feature if "dope sells itself".
- aaaaaaaaaaab 4y ago
  No, I’m talking about literal hemp fibers: https://youtu.be/QJAIFJtiRQo https://youtu.be/QJAIFJtiRQo That’s the traditional way of sealing joints. No chemicals, just hemp and your own saliva (you usually don’t have running water nearby when doing plumbing).
  - bohwaz 4y ago
    This is banned in Europe as bacteria develop with time, making it unsafe for drinking water pipes. Sometimes chemicals are safer.

zbrozek 4y ago

Is that one so bad in its end use? I would imagine production byproducts would be the bigger issue for plumbing tape, which is effectively solid and used in non-abrasive applications.

fuzzfactor 4y ago
The PTFE itself is really an inert polymer that is harmless to the water flowing through. It will not get into your water or break down through decay, those were considered superior properties. It takes a lot more heat to decompose PTFE than it does regular plastics, but once that's happening the vapors are a lot more toxic. But these are not the kind of plumbing fittings for welding or soldering. Chemically, ethylene is the gaseous hydrocarbon monomer that is polymerized to make the common polyethylene plastic, like so many milk jugs and other items needing a cheap plastic are made of. Tetrafluoroethylene (TFE) is the fluorocarbon monomer which is the fluorinated analog of the common ethylene. It's really rough and wants to spontaneously react with itself (or any number of other things) to form a bit of polytetrafluoroethylene (PTFE) polymer with somewhat explosive force under not-fully-predictable conditions. So nobody really wants to handle TFE. Instead extensive research at places like 3M and DuPont came up with a number of different alternative starting molecules that were less self-reactive but could still be coerced into forming PTFE as a final product. The PTFE was intended be a forever plastic like no other, but a variety of fluorinated starting materials and byproducts were also obtained some of which had interesting properties themselves. For instance some acidic PFAS compounds are not very inert on their own, one end of the molecule will firmly bond to some natural products like canvas or leather, which largely neutralizes their further reactivity. So after that those molecules aren't going anywhere until degradation of the substrate occurs. And the other end of the molcules possess the perfluorinated inert feature, forming an invisible coating which repels water like people had never seen. So it's all this other stuff, and the final degradation products (of those PFAS that have a decomposition pathway), that ends up in the environent eventually, many with a physical propery of self-dispersal. OTOH the PTFE is a solid plastic and just sits there permanently inert, no decomposition pathway, with little tendency for further environmental spread unless incinerated or microscopically pulverized, which disperses it as a byproduct gas, or very tough microplastic, respectively.

deleted 4y ago

[deleted]

bandyaboot 4y ago

I could be mistaken but I believe PEX has been the dominant type of pipe used in new water systems over the last 15 years or so. There’s not really any plumbers tape involved with the various types of fittings that are used with those pipes.

mh- 4y ago
Connecting the pipes, no. but connecting fixtures to those pipes, yes. Showerheads, faucets, etc. will all be screwed on and sealed with PTFE.
- bonzini 4y ago
  I have seen plumbers that are still using hemp.
  - DoingIsLearning 4y ago
    That's exactly what I did with all my faucets. Call me paranoid but I've taken them apart remove all the mangled PTFE tape and sealed the thread with hemp.

jefftk 4y ago

That's not correct. Neither PEX nor copper use tape, and that's been the vast majority of new water piping for 20+ years. In connections that do use tape, like old galvanized steel pipe, the tape is entirely within the joints, because it's a lubricant. (Just checked with my uncle who's a plumber)

kube-system 4y ago
Yeah, there is generally no PTFE in the middle of anyone's PEX or copper system. Thread sealant only goes on threads, and PEX systems are crimped together and copper systems are (generally) soldered together. Threaded fittings are expensive and so they're avoided when possible. But, either system will have often have PTFE at any terminations where transitioning to other fixtures via threaded fittings. [0] And occasionally there are brass fittings in the middle of these systems which are threaded and those will use PTFE as well. [0]: https://terrylove.com/images/homeowner/lee_01.jpg https://terrylove.com/images/homeowner/lee_01.jpg
zionic 4y ago
>PEX Yeah, rather than just the joints now the entire pipe is leeching toxic compounds
- jefftk 4y ago
  What does PEX leech?
  - aquaduck 4y ago
    My understanding is that polyethylene is one of the most benign plastics with respect to leaching, and that PEX should be even more benign than normal polyethylene because of the crosslinking.

stjohnswarts 4y ago

can you point me at an authoritative source that says PTFE is bad and not inert in humans (unless you reach a temperature of 500F or so)? All I ever see are "holistic medicine" and food babe level sites saying it.

refurb 4y ago

You realize we implant PTFE into human bodies as medical implants? What makes you so concerned about PTFE tape on a tap?

DoingIsLearning 4y ago
The FDA retroactively banned PFOA residue from PTFE coated stents and guidewires. So you would have had people with PFOA contamination during endivascular surgery prior to that. PFOA-free PTFE guidewires suffer higher risk of delamination, i.e. flaking of the ptfe coating which becone an embulus in your bloodstream. The FDA does an amazing job at keeping us safe but the more evidence we have about the effects of novel substances the more I am biased to applying a cautionary principle. In my pipe fixtures at home I will stick to hemp to seal the threads. If in the future I happen to need a stent, then I'll worry about it when I cross that bridge. :)
- refurb 4y ago
  Why do you assume that hemp is safe?
  - DoingIsLearning 4y ago
    Hemp is being used by Humans since the Neolithic, we have been eating, wearing, and building houses with it for more than 10 centuries. If it really was unsafe the data would have revealed it a long time ago. Synthesized fluoropolymers have been around for about 60 years with an overall poor track record for Health and Safety. If we apply a moderate cautionary principle towards novelty and also consider the minor life quality improvements that these 3M innovations bring (fluoropolymers only make things slightly less incovenient they are not ground breaking in my life), then it really is a no brainer decision.