Hacker News Reader

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)

View on HN

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

>PEX

Yeah, rather than just the joints now the entire pipe is leeching toxic compounds

What does PEX leech?

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.

Reply on news.ycombinator.com