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Comment by mikeiz404 | Hacker News Reader

Or even some household piping like PVC and PEX though with low exposure: “Phthalate exposure from drinking water via cPVC or PEX is low when compared to other dietary sources. Nonetheless, a shift from cPVC to PEX pipes in households would decrease potential exposure to phthalates.” [1]

1: https://hero.epa.gov/hero/index.cfm/reference/details/refere... with the full paper here https://ttu-ir.tdl.org/bitstream/handle/2346/87425/smith_art...

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cpvc isn't that common in household pipes, is it? it's for sun exposure, i thought. Heat PEX has the lowest numbers.

Are there any pipes that don't leach anything into the water?

For that to be true you would need chemically inert pipes, I can't really think of a material in common use that meets that specification. Opening the inquiry a bit to the less common materials:

Pure Soda Lime Glass

Synthetic Quartz

Diamond

Although these materials are poor choices for many reasons, they would be very unlikely to leach anything into the water more harmful than carbon or silicon atoms.

Don't most copper pipes get filed with a layer of limestone deposit? That basically acts like a calcium liner of sorts no?

This depends on local water hardness but generally is a stronger effect in hot water pipes because of the inverse temperature solubility of calcium carbonate.

Municipal water is definitely tuned to make a passivation layer on the pipe work.

> cpvc isn't that common in household pipes, is it?

From what I have read it seems CPVC is used for residential hot water lines when copper is not being used (and copper is expensive).

I was assuming cPVC and PVC were the same but that is not the case. cPVC is more specialty when compared to PVC since it can handle a higher temperature and pressure, and costs a bit more [1].

1: https://pvcpipesupplies.com/cpvc-vs-pvc

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Some additional but not directly related info found along the way:

- https://www.cdc.gov/biomonitoring/Phthalates_FactSheet.html

- https://www.epa.gov/sites/default/files/2015-09/documents/ph...

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