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Comment by maples37 | Hacker News Reader

What did you end up replacing it with?

I've done no research, but I wonder what the risk tradeoff is between a tiny amount of lead in contact with my drinking water (assuming copper pipes joined together with lead-based solder, not lead-free solder) versus the new plastic pipes that are becoming standard. I'm sure PEX is designed so that it doesn't leach plastic nastiness into the water, but I wouldn't be surprised if we find out that after a few decades it starts breaking down anyway and suddenly we have a whole new toxin in our drinking water and we need to replace half of the pipes in America again.

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The dose makes the poison here.

How much lead is permissible before it’s bad? The answer is, very very very little.

In comparison, you get copper contamination from copper pipes (especially if the water is too acidic), however the body handles a little copper just fine. It doesn’t build up in the body unlike lead.

Then you’re left with plastics: PEX or PVC. As of yet, there’s some potential concerns with microplastics in general… but that is from all the tiny plastic particles found everywhere, not solid pieces of pipe. And there hasn’t really be any evidence that it causes any specific known issue. If it was some giant problem (like lead in drinking water!) then the magnitude of effect would be much more obvious.

Yeah, the 'safe' level of lead is essentially zero. I think on the order of nanograms per liter.

Common wisdom is "there is no safe level of lead".

Sure, agreed. I’m just pointing out that the GP quibbles “what about microplastics” without comparing the known levels of lead (ie even extremely small amounts) that are unsafe. And it’s pretty obvious that high levels of lead lead to developmental issues. The same cannot currently be said of microplastics.

The underground feeder to your house is likely to be HDPE actually - which is chemically similar to PEX.

Both are made from Polyethylene, which is the exact same stuff oil (including food), gas, wax, natural gas, etc is made off. i.e. you body handles that all the time.

Wait... when is the last time you've drank:

- polyethylene oil?

- gas?

- natural gas?

- wax (I'm assuming candle wax)?

I understand you don't mean "drink" when you say our body "handles" it, but you do realize we don't make food from PET, nor do we usually "handle" gas and natural gas in any form of direct contact?*

* with the fun exception of a brief craze in my high school years where people would mix hard alcohol with gasoline to make cocktails "stronger". That's another story though

I'm not claiming you will get nutrition from it, I'm saying these thing are not toxic to the body because it has the necessary biological mechanisms to handle it.

It's the same way that, even though you shouldn't drink it, acetone is barely toxic, because your body knows how to process it.

I should remind you that there are other plastics, but polyethylene is not one of the toxic ones.

(Gas, as in gasoline, has benzene which is a different category. Note also that many plastics have plasticizers which are also a different category, although polyethylene rarely has any, it's possible that it could.)

>If it was some giant problem (like lead in drinking water!) then the magnitude of effect would be much more obvious.

If that was such an obvious problem, they wouldn't have put the lead pipes in the first place...

Science had evolved massively in 50 years. We used to put lead in gasoline too.

We've known lead was harmful for nearly 2,000 years though [1]. Compare that timeline to compounds created, widely used, and then discovered to be harmful in the past 50 years.

I am not advocating for lead or copper soldered water pipes, but I am conservatively skeptical about PVC being totally safe for the same timeline existing lead pipes have been in use. In July the EPA proposed raising the priority rating of vinyl chloride on its toxic substances list. It doesn't seem implausible to me that in 50 years we'll be taking about PVC pipes the same way were talking about lead pipes today.

I am not claiming that PVC water pipes are dangerous just that I am skeptical there is enough historical data to claim they are totally risk free. I am not a scientist or expert on this subject

1.https://penelope.uchicago.edu/encyclopaedia_romana/wine/lead...

Edit: added source

People knew lead was harmful in large quantities, sure, but the science around just how bad lead is and how little can cause damage I would say was not known.

Regarding PVC: It already is not used in almost any new construction for water supply lines, at least in the US. It's used for drains, but the leeching concern isn't really an issue for drain pipes. No water pressure, and no continuous immersion typically. Issues about BPA/vinyl compounds are

As per PEX, I can't say for certain that it's 100% risk free, but overall there is increased scrutiny on drinking water and contaminates and PEX right now seems to be the best choice.

I would assume they do leach microplastics and nanoplastics and require third party proof that they do not. From what I can find on the internet plastics leach micro/nanoplastics period. https://safepipingmatters.org/plastic-pipes-microplastics-im...

lead is extremely toxic even in small doses, microplastics are comparatively a non-issue.

Yeah, I can't believe this has to be said.

There is no indoor plumbing without tradeoffs. Copper, PVC, CPVC, PEX, etc all leach just different chemicals. Maybe copper with lead-free solder is best? Very expensive though

Before then, those of us with homes that aren't 100% rodent-proof forever have to factor in just how much mice and rats luuuuuv chewing on PEX hot water pipes. https://www.bobvila.com/articles/rodents-chew-pex-pipe/

PEX is easy to work with and cheap up front. The cost and risk are shifted onto the future owners.

Here in Europe, PEX is perfectly normal. The key difference is that we build our homes out of brick and mortar or outright solid concrete instead of wood, cardboard and glasswool, so pests have it much, much more difficult to cause damage.

> we build our homes out of brick and mortar or outright solid concrete instead of wood

I mean yes, you chopped down your forests millennia ago ;).

Nah, according to what I've read, we really ran out of forest (wood) and had to start replanting them about 500 years ago, give or take a factor of two.

Doesn’t Paris have an annual rat culling since their population of rats is like 10mil? And London is almost as bad as New York (which is also mostly stonework). The material hardly matters for rodents, as stone will make its own holes over time for them to get into, and the sewers in Europe are even older and in parts less maintained than the US.

Oh we do have rats but they live in the sewers and gutters where food waste ends up, not in the walls of our homes.

If you have rodents inside your walls or attic, you have a major issue unrelated to the PEX. Also, to my knowledge, the colored PEX is the main culprit. Clear variants aren’t nearly as “tasty”.

Either way, if you have rodents inside… that’s its own issue.

Do you argue against layered security in your day job? I'm making a case for reducing blast radius in the event of a breach.

Of course rodent issues are related to PEX: now if a rodent ever does get in, the damage is multiplied when they eat your delicious PEX water pipes and you get a flood in addition to all the other horrors. Not so with metal piping.

It would be nice if all homes on earth could be completely 100% rodent proof forever. And it would be nice if attackers never breached computer systems. But some of us have to live in a world where such things happen.

You’re over prioritizing an edge case while ignoring benefits, I’d say.

If you want to talk about blast radius: PEX is substantially more resistant to freeze bursting. What about houses that are poorly insulated, so they are prone to pipe freezes? Copper pipes would be ill advised in that situation. I assume the same houses that are prone to rodent infestations are also poorly insulated. Which is more likely to happen I suppose depends on your climate.

Maybe I'll run it by my homeowner friend who suffered through the rat-chewed-PEX flooding that a PEX booster I came across considers her experience an "edge case". If I want to see her cry tears of blood, that is.

For good measure, I might also remind her that notwithstanding the flooding, the rats were a "major issue". Just in case she was confused about that!

My copper pipes have with some regularity gotten small pinholes that blossom from tiny drips into tiny high-pressure jets. (E.g.: https://whyrepipe.com/blog/what-causes-pinhole-leaks-in-copp...)

The longer I have a home, the more I realize every thing has its gotcha's.

Entropy is a bitch.

Replaced it with higher-end pex. Yes, there is a trade-off there, but to me the effects of lead over long periods of time are very scary. I also have a filter for our actual drinking water that is able to filter some micro plastics as well.

You're going to find 'health problems' with every pipe material. Even stainless steel will contain trace amounts of lead or another toxic metal.

And if you have hard water, stainless steel will still oxidize (rust).

> You're going to find 'health problems' with every pipe material...

IIR, larger chemistry laboratories often use glass & quartz pipes to distribute distilled water. Though the direct costs of such a system are relatively high.

The gold standard is copper + lead-free solder for incoming pipes, and PEX for sewer/outgoing.

I wouldn't use PEX for fresh water pipes.

PEX for DWV (drain/waste/vent)?

I’ve seen ABS and PVC (and, of course, cast iron) for DWV, but don’t think I’ve ever heard of Pex for that.

PEX isn’t new, it has been in use for at least 50 years by now

I know there are at least two types of PEX, if you do replace pipes make sure you use the highest quality stuff you can get because PEX isn’t just PEX

Copper pipes + lead free (silver) solder is also an option.

Yeah I'm too lazy to look up a source now, but I did look it up and both types of PEX will leech microplastics into your water.

It sounds like a big facepalm, and it kind of is, but it's not a crazy idea to filter your water at the taps: you probably only have 2-6 of them anyway. I'm a fan of the whole-home water filter, but yeah then you've gotta be confident about your pipes.

I'll take microplastics over lead any day.

The dose makes the poison.

I'd choose micro plastics vs an equivalent mass dose of lead.

If it was 1000x the amount of micro plastics vs lead it's maybe less obvious which is the less bad poison. I'd have to do some research at that point.

I think framing it this way it's obvious that lead is worse than micro plastics. But when you go from lead soldered copper pipes to PEX I don't know what the doses you get from each are.

I think its very obvious 1000x microplastics is much better than the lead.

Maybe if you said a billion times.

Okay what's the safe dose of micro plastics? What's the evidence for that dose being safe? Do we have 100 years of data?

The reason we know there isn't a safe dose of lead is a lot of study.

Every month there's a new study about some crazy micro plastics things where they got found in some new place. We're in the early days of figuring out how bad it is. We don't really know yet.

Sure, but (maybe someone can jump in here) isn't copper pipe + water soluble lead-free flux + lead-free solder better? Copper piping is more expensive--dunno when you'd make your money back over tap filters, but broadly I don't think you have to choose between lead and microplastics in your water from your piping.

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