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Community and Q&A

Plastic pipes/ hot water tank – leaching chemicals….

eMJCVGSEok | Posted in Green Products and Materials on

Scientists say plastic chemicals leach into the heated water.
Some people choose not to believe it; perhaps because they sell or work with it – i dont know.
I prefer to stay on the careful side.
I have a hormone imbalance due to plastic chemicals found in my blood, causing me major health problems which started when all our pipes got changed over to plastic.
My water was tested and found to have much higher levels of “poly-chemicals” than non -plastic plumbed water.

My pipes are plastic, and my hot water tank is glass inside, but the tubes going in are plastic.

We can change the pipes to copper, but our confusion here is what to do about the hot water tank tubes.
The tiniest amounts of these chemicals are dangerous, becuase the tinist levels matach those of the body.

So :
1. Are there metal hot water tank tubes?
2. If so are they made of just one metal (to prevent electrolysis)?
3. Then if all that is well, are there NATURAL sealants to goop on the threading after? (because teflon is one of the most toxic substances man has ever burdened the earth with)

If none of this is possible, and i can’t go back to 1940 to find a “golden treasure” of a natural hot water tank……..then what options are there?

Can i find another way to heat my home without spending thousands and thousands of dollars?
Waht about a boiler lol…..


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  1. GBA Editor
    Martin Holladay | | #1

    First of all, water supply pipes are not made from poly vinyl chloride (PVC). PVC is used for drain pipes and vent pipes. Plastic water supply pipes are made from polyethylene, the same plastic used to make milk bottles.

    I don't know whether any manufacturers make tank-style water heaters without plastic dip tubes. But I'm sure that all tankless (instantaneous) water heaters have metal water tubing made of copper or stainless steel.

    Back in the 1940s, before the invention of Teflon tape, plumbers used pipe dope on pipe threads. You can still buy pipe dope at any hardware store. However, it's possible to build a house without any threaded fittings that require pipe dope or Teflon tape if you want to; just use soldered fittings, compression fittings, or flared fittings.

  2. davidmeiland | | #2

    Martin, I'm no chemist but I believe a lot of PVC is used for water supply out here (with CPVC for the hot side) or at least it was before PEX caught on. In fact my house has a few remaining feet of PVC where I have yet to finish re-piping. I think you're right that most or all of the gas tankless heaters are all-metal as far as the water pathway is concerned, at least my Takagi appears to be. A customer of mine has an electric tankless that appears to be all-plastic.


    First stop drinking or cooking with hot water and get a good shower head mounted water filter to take the chemicals out of the shower steam you inhale while bathing. (or shower with cold water)

    Second get a reverse osmosis filter under the kitchen sink, pipe the ice-maker to it and stop drinking water from elsewhere in your house.

    Third install a central vacuum system with outdoor exhaust so you don't poison yourself by running the vacuum cleaner.

    Then look at the big picture of your overall living environment. do you have scotch guard fabric, soft urethane foam padded furniture or carpeting with re-bond foam padding in your house? Soft vinyl shower curtains and furnishings with pthalate plasticizers? There is a good likelihood that the water pipes are a minor factor in the poly-chemicals in your body as compared to the home furnishings and flooring.

    The Green Science Policy Institute will be a good resource for the issues you are having. There are plenty of actions you can take that won't cost a huge amount of money. The water heater is probably not the biggest offender here.


    I would also have your water re-tested, we recently had a well tested that came up with dangerous lead and selenium levels shortly after drilling and shocking w/ chlorine and running for 12 hours to flush the chlorine out. Had it retested after three weeks of normal use and 8 hours of rest and lead level was zero and selenium normal. Looks like we just had a lot of rock dust in the water.

    I'd want to know more about the poly-chemicals you had in your blood test and see where they would relate to sources in your environment and diet.

    Remember that people focus on "out gassing" but dust from product abrasion is equally of concern. Pets are like dust magnets and their fur can be pretty heavily loaded with halogenated flame retardants etc. Definitely wash hands after touching pets. I had an article in the Kitchen and Bath special issue of Fine Homebuilding this fall that covers a lot of this that you may want to read.

  5. eMJCVGSEok | | #5

    thanks so much all of you.......oh and what i have is "pex" ( not mistake) it i all the same to me lol.
    They all have "stuff" in them that produce xeno-estrogens.....a major reason women today are going nuts with pms and thyroid problems...... 100 years ago pms was pretty mild...... compared to now.

    A quick question for pipe dope pretty natural? whats in it?


    Pipe dope is not natural in any way. it's made of grease and teflon, but it is only applied to the threaded connections which are very few of in a typical PEX or CPVC plumbing system.

    PEX (cross-linked poly ethelyne) is connected with copper crimp fittings on brass insert fittings and the only thing in contact with the water is the pipe, which is cross linked, and the fittings, which are generally brass and copper. My understanding is that the reason Quest Poly Butylene was outlawed and replaced by PEX is because the old Quest PB pipe needed plasticisers (pthalates, one of the "poly-chemicals" you are concerned about) the new cross linked PEX is much safer and more durable than CPVC or copper. Not perfect but a big improvement.

    CPVC is connected using a very volatile acetone-like methyl ethyl ketone solvent. Leaching studies commissioned by the State of California and conducted by UC Berkeley found that CPVC plumbing pipe systems may leach potentially toxic chemicals such as chloroform, tetrahydrofuran, methyl ethyl ketone, acetone and organotins into drinking water. These chemicals may cause cancer in humans or other serious health impacts. When leached from CPVC plumbing systems, the public may be exposed to these chemicals through consumption of drinking water, inhalation and skin exposure during bathing.

  7. wjrobinson | | #7

    I use Uponor plastic fittings with PEX. I have no idea if the fittings give off something of concern.

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