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.
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.
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?
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)
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.
Yeah, rather than just the joints now the entire pipe is leeching toxic compounds
Call me paranoid but I've taken them apart remove all the mangled PTFE tape and sealed the thread with hemp.
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.
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. :)
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.
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.
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".
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).
Sometimes chemicals are safer.