Alternatives to PEX piping to avoid chemical contamination and off-gassing?
Just curious if anyone has insights on plumbing piping. We are starting our plumbing rough-ins very soon, maybe even this week, so it might be too late to discuss this.
Today I came across this article, which includes several citations, and noticed there is also more research since this was published back in 2017: https://www.ewg.org/news-insights/news/amid-pipe-wars-researchers-wary-plastic-pipes-leaching-chemicals
In summary, PEX piping contaminates water and there is huge variation between brands and even within brands based on batch. It does seem worse at the beginning, as new piping must be flushed for some length of time to “remove” the contaminants and off-gassing. Considering this will just end up in our landscape and ultimately poison the land and water system, this is disgusting.
I am wondering if it is unreasonable to request copper pipes, I know all old houses used this so I am not sure if there are disadvantages or issues other than cost. Or maybe another plastic such as polypropylene?
This is not something I have ever thought about… but the research is concerning. I do not like the idea of plastic tubing contaminating the nice clean well water. At the very least it seems we could install a drinking water line to the kitchen using copper.
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Izzza,
Where dos your domestic water supply come from, and what type of pipes are used?
Water is coming from an aquifer, we recently drilled the well. I am not sure what type of pipe the plumber installed from the well to the basement mechanical room though - good question. Wish we had been asked about this but there does not seem to be much public knowledge about the topic yet as it takes a long time for research to reach people, especially without regulation. I highly doubt our plumber (who is great) is spending his time reading about chemicals leaching from plumbing pipes. But he might be receptive to discuss alternatives as he seems like a smart guy.
We also haven't tested the water yet so I don't know about the pH... which seems to be a determining factor for copper.
From the linked article:
"We have seen significant amounts of chemicals leaching from new PEX pipes across brands and differences even within the same brand of pipe purchased from different stores," Whelton told EWG. He said the pipe materials are not tested once they are installed to see the whole range of chemicals that could leach into water and that most of the substances released into the water have not been identified. Even if the chemicals that leach are not known to be toxic, they could fuel the growth of bacteria in the pipes or cause bad odors, he added.
Whelton said homeowners who have already installed PEX pipes should flush them to reduce the amount of chemicals that could leach into water – the longer the better. In some pipes, researchers have seen significant leaching even after 30 days of use.
I'm not sure that "leaching" is the right word, I think of that as dissolved substances in a solid moving to an adjacent liquid. The problem with PEX seems to be that it's contaminated -- it leaves the factory with chemicals used in its manufacture still on the pipe. In time it cleans up, but during that time those chemicals are going into the water. The article doesn't point to any long-term problem.
Looking at the chemicals, I think a little bit of detergent squirted in the pipe during installation, and then flushing with water until the detergent dissipates, would probably solve the problem.
That organization is supposed to made up of scientists and they chose the term leaching which as you state implies that water draws and dissolves material from the pipe. You would think we would see pipe instability and failures if this occurred on a meaningful level.
We used to have copper pipes with lead based solder, then we replaced the solder. There was time when Poly B was supposed to be great, but it developed pin holes and leaked in houses and had to be pulled out. PEX is a form of polypropylene and has been used for decades all over the world. You would think there would more studies especially in Europe if leaching was a issue.
If you are concerned, I'd just install a reverse osmosis filter on the drinking water supply.
PEX is cross linked polyETHYlene, not polyPROpylene. Different materials. I haven't seen much in the way of polypropylene used in plumbing pipes though -- usually you see CPVC, PVC, or PEX. Polyethylene too, which is probably what was used from your well pump to your home (in answer to your post #2, above).
Bill
Well water has lots of contact with plastic/petroleum type chemicals long before it reaches the waterline heading into your basement. I don't see anyway around it to avoid leaching.
Let's start at the beginning. The well pump is stainless steel but when new is coated in machine oils, and may also have some plastic/rubber internal components that contact water.
The waterline to the bottom of the well is plastic/pvc, the well casing supporting the well is either metal and/or pvc pipe.
The submersible grade electrical line powering the well pump at the bottom of the well has a petroleum type coating.
There may be a 10 micron filter sleeve over the pump, if so that's made from schedule 40 pvc pipe, there are also rubber fittings that attach it to the pump.
There likely are rubberized stabilizers supporting the electrical line and waterline in the well casing.
There is likely a submersible grade tape used that wraps the electrical line to the waterline throughout the depth of the well, and its adhesive has a chemical composition.
Lastly, the water line into your basement is plastic, and the water is fed into a pressure tank that has some type of petroleum made rubberized bladder that regulates the domestic water pressure.
At this point in the plumbing schematic, you have a choice of copper or pex throughout the home. My preference is copper.
Dilution is the solution to all chemical concerns, over time it will average out. Hands down I still prefer well water over city water supply anyday.
I am not sure whether it is technically leaching, it might be both leaching and off gassing. It isn’t a huge surprise, it seemed like the world was shocked to recently learn plastic water bottles leach chemicals. Like that seems like common sense… store water in plastic, water slowly absorbs little micro particles of plastic. I think this is a problem… without long term testing data, one cannot claim there are no long term risks, right? Its easy to so you’d think there would be studies.. I’d think there would be a lot of studies about a lot of things, there are only so many scientists all working as fast as they can to study many topics in this world. I reviewed a few studies so far and there simply is no evidence that PEX tubing is safe or optimal for human health as far as potable water… please share if anyone has resources! I only found out about this yesterday and haven’t done a deep dive because part of me doesn’t really want to know because it’ll be impossible to unlearn and we might have no other choice at this point.
Also, it is absolutely absurd for manufacturers to suggest people just flush the lines for a couple weeks to get rid of the chemicals. They don’t evaporate… they pollute the earth. There is no “getting rid of.” The whole concept of waste is so flawed. It is not complicated: bunch of disgusting chemicals are in the tubes, water flushes chemicals into the water system which in my case is a newly installed septic on pristine land that is upslope from a wetland area which feeds the drinking water supply for local communities including a large city to the south. Fill the water table with forever chemicals and all of this garbage that should not be there - poison everyone. Slowly but surely, us humans are doing a real number on this planet. Sure, the companies could thoroughly clean the tubing before selling it which would help… but realistically they would be dumping the contaminated water right back into the ecosystem if it is not regulated.
Flushing the lines might improve the immediate problem of contaminated household water, but it creates a problem downstream where we are all contributing further to destroying the planet by flushing toxic man-made chemicals down the drain with literally no idea of the consequences.
I know “chemicals” and plastics can’t be totally avoided, it still seems worth trying to reduce wherever possible. I agree about dilution! Also, it is water temperature related so cool well water is one thing and hot household water flowing through plastic is another!
Capecodhaus - can you explain why you prefer copper?
I am eager for the plumber to get the water tested. I wanted to avoid RO because it is wasteful and then you’re drinking dead water so having to remineralize it is a whole other thing I have not looked into.
PEX is cross linked polyethylene
Polyethylene, like milk bottles
I too prefer copper piping, but it is expensive
Most pipes get a layer of 'stuff' on their inside that limit contact with the water. That is why we didn't all die of lead poisoning when lead pipes were common That whole nightmare in Michigan was because a change in chemicals stripped that stuff off and exposed lead.
I think I would want a more specific and accurate assessment of the 'dangers' of PEX before I made any decisions regarding it
>"That whole nightmare in Michigan was because a change in chemicals stripped that stuff off and exposed lead."
Not exactly. What happened was they stopped treating the water correctly, which altered the water chemistry sufficiently to allow some of the lead in some of the pipes to dissolve into the water. Flint had been supplied by the detroit municipal water system for quite some time, but their city council decided to save money by supplying their system from their own Flint river instead, which was otherwise their backup source of water. The Flint river provided water that needed to be treated very differently from that provided by the detroit system (the Flint river water was slightly acidic if I remember correctly), and the city never made that change. The city had been warned multiple times by area industries that were noticing the problem, but they didn't act until it became a big public issue. Even then, it was only SOME pipes in SOME areas (generally older areas), that were made of lead. Coatings on the inside of the pipe had nothing to do with it. It was all water chemistry changes caused by changing the water source which was done by the local city administrators who then cut some corners by not chemically treating the water properly prior to distribution.
Bill
I don't know that we are disagreeing here. There was lead contamination in the water system. The pipes didn't change, the source and/or treatment of the water changed, causing lead in the system to become dissolved.
https://www.smithsonianmag.com/science-nature/chemical-study-ground-zero-house-flint-water-crisis-180962030/
.....The corrosive water pumping underneath Flint quickly ate away at the protective layer inside the city's old lead pipes, exposing bare lead to the water flowing through them. This lead was the source of the initial contamination, Edwards says.....
which was my initial point
We had the exact same thing in DC here around 2002. The local water authority changed the chemical they used to disinfect the water. It ate away the protective coating of slime on the interior of pipes and pipes that had been fine for decades starting leaching lead. The authority's first impulse was to try and cover up what they had done, and they were somewhat successful so it wasn't a major scandal like Flynt.
It's not a "protective layer" of gunk that keeps the lead from leaching into the water with lead pipes, it's the chemistry of the water itself. Lead is stable (i.e. won't leach) with certain water chemistries, and not with others. I think in Flint it had to do with phosphate levels, but I didn't bother to look that up so don't quote me on that :-)
Bill
I lived through this. My house had a lead service line and my kids were poisoned (mildly, thankfully). This isn't my theory, it's what DC Water told the public. DC had a lead problem before they changed the water chemistry, the water would dissolve lead, but it was only really an issue if you disturbed old plumbing. When they changed the chemistry all of a sudden old plumbing all over the city got exposed.
Before my kids were born I had my water tested, no detectable lead. After the change it was several times the legal limit. I don't remember the actual number, but I remember that my reaction when the test results came back was that there had to be something wrong with the test.
From Science Daily:
" As the pipes corrode in the presence of free chlorine, a certain type of lead, PbO2, can build up on their interior surfaces.
That buildup typically isn't a problem. In fact, so long as free chlorine is being used as a disinfectant, the PbO2 is actually a positive, according to Daniel Giammar, the Walter E. Browne Professor of Environmental Engineering at Washington University. This form of lead has a low solubility so it stays in a solid form on the pipes, instead of in the water.
PbO2 is not always so benign, however. "There is a potential risk because the solubility is only low if you keep using this type of chlorine," Giammar said.
Switching to a different disinfectant such as chloramine -- the mixture of chlorine and ammonia that Washington switched to in late 2000 -- causes the lead to become water soluble. The PbO2 then dissolves quickly and releases lead into the water system."
https://www.sciencedaily.com/releases/2020/01/200122175650.htm
The "slime" is a coating of PbO2 on the inside of the pipes.
This seems a bit overblown. The study (although what I could see showed no data, only the abstract, intro, and snippets) showed a huge drop off after day 3, indicating it’s manufacturing residue. And at the same time they don’t indicate what the chemicals or levels are, they just say total organic carbon. They do mention the saw trace toluene but not how much. Just flush your system, which brings me to your “pristine” land.
Are there any roads near your house? Do you have wood siding that is being sealed? Or for that fact, any metal that was shipped with corrosion coating (grease) like rebar? Did your contractors have a dumpster at any point? Do you drive a car, or has anyone driven a car with even a minute oil leak on your property? I would bet that any one of those introduced thousands of times more chemicals into the land then the trace amounts found in pex.
Lastly, copper…. The study itself indicates that it uses between 25-60 more energy and produces 30-70 time more co2 than pex, so are you just shifting your pollution?
I would focus on things that are actually known to cause human health hazards rather than speculate based off a single study that has no conclusions on whether this has any applicability to your health, but that’s just me.
Oh also these are not forever chemicals, for those, look at your rain jacket…
I had a plumber do some work that included new pex to the kitchen sink. It tasted terrible, which I found distressing because previously it had tasted great. I added a filter and it tasted fine. I realize your concerns are about more than your own exposure and the taste, but I though that experience might be useful. It's been more than 5 years, and I should probably taste it again and see if it tastes good new. I imagine it does.
Copper is still a viable alternative, if expensive. You could consider copper to the kitchen and PEX elsewhere.
Polypropylene is great, but the installation requires special thermal fusion (welding) equipment. So finding an installer for that is hard and repairs might be hard in the future.
Great comments, thanks!
Doesn't seem like the end of the world... I will ask how much it would cost to upgrade to copper. I also have not looked into this but it seems there is more involved than just CO2 emissions from production, as the byproducts of producing the petroleum based plastics are pretty nasty and I'm not sure how it compares to copper without a full evaluation rather than simply comparing CO2 or energy use.
All this to say I have a large collection of Lululemon garments that are basically fully of 'microplastics' so I'm not sure a bit more in the water will be what does me in. Just curious if it is easily avoided for the plumbing, in which case we might as well unless the cost is extreme.
Does anyone have an idea how much $ we are talking about here? What does more expensive mean? In my situation it is a 3 level ~ 3,400 sq ft house with 2.5 bathrooms and 1 unfinished bathroom in basement, kitchen, mudroom and laundry room have plumbing. Is switching to copper piping likely > a few thousand $?
If you're interested in the economic impact of producing copper, search for "Pennies from Hell" by Edwin Dobbs.
I meant environmental, not economic.
Corbett Lunsford just released a video on his Youtube channel called "The Science of Sick Building Syndrome and Environmental Sensitivity" and in it they discussed the fact that when Pex is tested in a lab the scientists were told that the tubing had to be regularly flushed out with fresh water for 14 days in order for the contaminants leaching into the water to drop below a safe level.
Minute 18:40
https://www.youtube.com/watch?v=RHT71u1ipbo&t=152s
“Does anyone have an idea how much $ we are talking about here?”
Copper is about 500% more $1.35 per foot vs $0.28
https://www.forbes.com/home-improvement/plumbing/pex-vs-copper-piping/
Walta
Not insignificant, but if one is not building 1000 houses....quick glance at The Despot I would guess maybe 500 bucks in pipe for plumbing in my house, plus fittings. Not nothing but people pay a grand for a shower fixture
gusfhb,
That's just materials. The labour is probably in the order of three to four times more expensive. It's not only the fittings, but things like running across joist spans, or horizontally on walls, are much harder with rigid pipe than with pex.
Just responding to the post..........man hours saved is surely a thing.
Consider getting a reverse osmosis filter tap for your drinking / cooking water.
When on a well you want one with a permeate pump the uses the energy from the waste water to make the filter more efficient.
Walta
I asked for copper to the kitchen (at least on the cold water line) and they refused. The local municipality only allows direct bury HPDE (high density PEX) from the meter to the house so at that point its sort of useless to switch back to copper.
I would request Uponor Type A Pex, both because it is impossible to forget to crimp those fittings, and because Uponor is at least a trusted, known brand, as opposed to some 3rd party "equal."
HDPE is High Density Polyethylene, it is NOT PEX. PEX is cross linked polyethylene. They are not the same chemically. The cross linking is actually supposed to make the material more chemically stable, and also capable of handling higher temperatures.
Polyethylene in general is a very stable material that doesn't react with much, and doesn't really leach things into water, either. I agree with some of the other posters that mention the issue seems to be more with manufacturing residues than with the material of the pipe itself. That implies a flush/clean cycle is a good idea, but that's been recommended forever! You're ALWAYS supposed to run a clean+sterilize solution through new pipes when you are on well water! City water is less of an issue because it's chlorinated, and the chlorine takes care of disinfecting your new pipes.
Regarding the different materials, PEX and PE should be pretty stable as far as plastics go. PVC slightly less so, but it doesn't really matter for the typical application for PVC (drains/vents). CPVC I haven't ever really looked into. Copper can leach copper too, and copper is actually pretty nasty to most living things, it's just that so little gets into the water that it doesn't matter much. The same goes for soldered connections: very little lead is typically in contact with the water, so there usually isn't anything to worry about with soldered copper connections. The issue with lead in water is much more of a concern with the old underground water pipes that fed individual houses, which were MADE OF LEAD. The mains were usually cast iron, concrete, or sometimes hollowed out old logs. Now, in modern times, water mains (except for the very big ones you can walk through), tend to be made of HDPE, which is a very stable and long-lived material.
BTW, I suggest anyone on a well get a "real" lab test, not just a county test that only checks a few things. You can have nasty things in well water too, many of them naturally occuring. Just because you're on a well doesn't necassarily mean that your water is completely safe to drink and "natural". Always remember that the plague was all-natural and organic too, and it killed a huge chunk of the population of Europe back in the day...
Bill
Thanks Bill! I agree I want a FULL lab report on the water. I understand our plumber will get the water tested, how do I go about getting a proper test done? Not sure if this is something he will have done or if I should figure it out myself before we decide on the treatment equipment. I guess I can just look up water testing in our area but if you have any recommendations of what to look for or certain contaminants to test for that would be great!
Usually there will be a tap right where the well line enters the house. I'd do two tests, one there, one at the fixture furthest away. The idea is if you find contaminants, you want to know if they're in the water when it enters the house or being introduced by the plumbing.
You want any tests specific to your area done, which may include E. Coli, fecal coliform, etc. NO3 (nitrates) is another I'd check for. BE SURE to check for iron, manganese, phosphate, and calcium (usually shown as "hardness"), since that stuff you need to know to be able to design a treatment system for the water. pH is pretty standard, and not as important in some ways as people think, but you do want to have that info. After that, it gets more complex (aside from the usual base test stuff that your county would have done). You can ask to test for anything else you are concerned about, like MTBE, or dissolved gasses (methane, radon). If you have them test for most everything, you'll probably be around $400-500 for the test, but it depends on exactly what "everything" includes, and it depends on the test lab. The NSF people used to have test lab references if you need to find a lab.
Bill
Thank you! I’ll look into this a bit and see what I come up with. I know I want to test minerals because I’ve been dealing with hard water for a few years and it is horrible mainly for my hair. I’ve heard about chromium/hex 6 so I was thinking to ask about that too. I don’t mind spending $500 for testing, seems well worth it! What blows my mind is that there is no “smart well” tech with sensors within the pump so you can track water quality.
I don't think there are any sensors that can read this many different things. The only thing I can think of that could reliably do that would be a mass spectrometer, and I've never seen one of those for continuous flow applications (I did get to play with one a bit back in college though). Most of the lab tests use chemical reagents to do the testing. I like the titration type tests over the color change type tests for home test kits, because the titration types tend to be easier to get reliable results with. Titration test kits are the kind where you cound drops, or dispense one reagent into another using something that measures mL of reagent. You do this until you see a quick color change, but it's the amount of reagant that was titrated ("dripped") into the other that gives you the result, not the precise hue of the color in the test vial.
For hard water, a water softener is usually all you need. If you have lots of iron in the water, then you need an iron filter. Small amounts of iron can be handled by manganese greensand in disposable filter cartridges, but higher levels of iron are better handled with the fancier setups that can be rechared (to greatly save $ on filter parts!).
Bill
Do people really forget to crimp fittings? You'd get instant feedback on that mistake as soon as you turned on the water.
Tim,
If you pressure test, but I've seen un-crimped pex fittings hold water at 40 psi.
At least for a little while.
That's the problem too -- a barb will hold, for a while. You end up with timb bombs hidden in the walls. Then, one day in the future, you have a really bad day. Mr Murphy tends to make sure those fittings fail at especially helpful times too, such as xmas morning at 3am, while you're on vacation away from home...
Bill
You might not forget to crimp but you may forget the compression ring… there is always a way to mess it up….
Thanks everyone! So it looks like our plumber will do copper in the mechanical room and then Uponor Type A PEX for distribution lines. Seems like this is a well liked product so it is probably fine… guess we will just try to flush the lines as much as we can at first even though it seems so wasteful!
DC suggested adding a bit of detergent to the lines during install, pretty sure the plumber will think I’m crazy wanting to put Dr Bronners Sad Suds in the lines but um I like the idea 😂
You could also easily plumb in a way to add detergent and flush your lines at any time in the future if desired, you may already have something inline that can achieve this, such as a spin down filter.
Another lesser known alternative is PE-RT, which is chemically simpler but slightly physically inferior to PEX (still meets all durability standards). It is greener in manufacturing due to fewer chemicals being used and having a simpler process, which is also clearly reflected in the price. My guess is it would also have fewer chemical contaminants than PEX. It is also theoretically recyclable unlike PEX.
It has decades-long track record in Europe and is fully approved in the USA, but is virtually unknown in residential in USA since change is slow in this industry and plumbers have been burned by new product failures in the past (poly-b, dezincification).