Health Risks from PEX and other Plastic Pipes

Here are several of many web links that say PEX and other plastic pipes are not healthy, impart a foul taste to water, and has other issues. At the same time, it appears that the actual risks are not exactly known. Either way, it appears that copper pipe is a much better choice, as far as health, and water taste.
http://www.alternet.org/environment/drinking-water-it-safe-when-delivered-through-plastic-pipes
https://www.angieslist.com/articles/does-pex-piping-affect-drinking-water-quality.htm
And From: (read below) http://healthybuildingscience.com/2015/10/30/new-construction-piping-plastic-vs-copper
Piping for New Construction: Plastic vs. Copper What Do We Know – What Should We Do?
Water, it has been revered since the beginning of time. It sustains and nourishes us; we couldn’t live more than three days without it. Fortunately in the Western World it is readily available. It is so seamlessly intertwined with our daily lives that we rarely think about the system that delivers it to us. However, the more we know about our water system the more empowered we are to make sure we are getting the highest quality water possible. Which type of piping is better: plastic vs. copper .
This blog post will focus on information researchers have discovered that highlight the safety issues surrounding different types of potable water piping material, namely HDPE, PEX, PVC, and Copper Piping. Weighing the risks, it will pose the question of which piping material should be used for new construction and renovation projects. If you have any thoughts or considerations on the matter please suggest. Though the findings are compelling and an important part of the puzzle, they are in no way comprehensive. More studies and respective innovation are needed to fix the problems and create a better system.
plastic vs. copper
PVC Plastic Water Faucet Plastic Piping
Okay, let’s address plastic piping first, specifically HDPE, PEX, & PVC.
Plastic piping was introduced to the United States in the mid 1980’s and has become increasingly popular – not surprising. Plastic piping is easy to install. Its route through the building can be more versatile and potentially contribute to making the building more holistically designed—(suggestions and case studies that have done this are welcomed). Plastic piping is also less expensive which obviously helps with budgeting and money allocation. It can also be used for 50 years or more.
However studies are showing that chemical compounds found in plastic piping are leaching into our drinking water. Though testing is still in its nascent stages, studies have concluded that High Density Polyethylene (HDPE), Cross Linked Polyethylene (PEX), and Polyvinyl Chloride (PVC) pipes, release both regulated and unregulated VOCs (volatile organic compounds), unidentified contaminants, and assimilable organic carbon (AOC) that can possibly lead to microbial growth.
A 2015 study conducted by Andrew Whelton and his associates at the University of South Alabama & Purdue University, is a particularly good source of information. The study tests for VOCs, AOCs as well as other compounds in PEX, HDPE, PVC and PP pipes. The VOC testing is generally aimed at PEX piping. Additionally, the paper expands its breadth beyond its results by referencing the findings of other studies that discovered similar contaminants.
Here is the link to read the study in AWWA (American Water Works Association) Journal: PEX and PP Water Pipes: Assimilable Carbon, Chemicals, and Odors
To briefly surmise: Whelton and his team’s results showed the presence of VOCs including ETBE, cyclohexane, toluene, and xylene in the water of eight PEX pipes over a 30-day cycle. According to the paper, “ETBE, toluene, p-xylene, and unspecified xylene isomers have been previously found in PEX contact waters.” These studies include: “Skjevrak et al., 2003; Koch, 2004; Durand and Dietrich 2007”. Whelton’s results indicated that VOCs were higher in the beginning of the period, and in some cases, were not present at the end. Only ETBE and cyclohexane remained detectable on day 30 but these were below NSFI 61 standards.
The studies referenced above differed for PEX piping. For instance the 2014 study by Kelly et. al. showed the presence of both toluene and ETBE (65 ug/L) on day 30. Durand and Dietrich’s 2007 work showed ETBE levels ranging from 0.14 ug/L to more than 100 ug/L; and a particularly alarming test at an Oklahoma home found ETBE levels at 22 ug/l and toluene levels at 80 ug/l after a year – these levels are above OTC thresholds. In addition to PEX, a study in Norway presented at the 20th No Dig Conference at Copenhagen (2002) (link below) found that “five out of seven tested brands of HDPE pipes showed unacceptable TON values of test water.”
Here is the link to the No Dig Conference study entitled:
Potential water quality deterioration of drinking water caused by leakage of organic compounds from materials in contact with the water.
What can be determined by these varying answers? In the case of Whelton’s, is PEX piping really all that dangerous if only a few VOCs are present after a 30- day cycle- and are below NSFI 61 standards ? Though we should eventually find this answer out, the conclusion does not account for the other instances VOCs were found. Is there a way to shorten the leaching period, or better yet eliminate leaching all together? Let’s move on to AOCs.
Whelton’s study found that six of the eight PEX pipes had AOC levels exceeding 100 ug/l on day 7 of the cycle- just to note 100 ug/L of AOC is when coliform detection occurs. By day 28, however, none of the PEX pipes exceeded the microbial regrowth threshold. Similarly AOC levels for HDPE and PVC brands increased by 22% ug AOC/L and 58% ug AOC/L respectively over the course of the 28-day cycle but did not exceed 100 ug/L on day 28. The study listed at the No Dig Conference (referenced above) states that “ PVC and PEX have a higher biofilm growth on their surfaces than the glass reference,” however in this study, the AOC presence also diminished over time.
Similar to VOCs, AOC results vary within each study as well as when compared to other studies. Do AOC levels pose a risk if they reach the coliform threshold in the beginning of the cycle but not at the end? Should we be weary of AOC presence altogether? Can the quantity in the pipe grow after thirty days?
More research needs to be done to ascertain what’s going on. Compounds that we don’t want in our pipes are being found. In addition to the presence of VOCs and AOCs, Whelton’s study detected that “a significant number of unknown compounds spanning from low to mid molecular weight are present in PEX pipe contact water.” How do we evaluate these mysterious chemicals? Similar to VOC and AOC findings, what are the health implications?
We have to find this information out if we can truly vouch for plastic pipes’ use. It’s difficult and disrupting to the industry, but if we can avoid ingesting volatile organic compounds that are carcinogenic, endocrine disrupting, and neurotoxic in our pipes, we should – even if they are in small quantities. Similarly it’s obvious that we don’t want bacteria forming in our pipes. Therefore, we need to fully understand what causes AOCs to form and how to prevent them. As for the contaminants that we do not know – well that just opens up a whole can of worms to be figured out.
plastic vs. copper
Piping for New Construction: Plastic vs. Copper. Copper Plumbing Copper Piping
The primary alternative to plastic piping is copper piping. Copper piping has been around since Ancient Egypt; it is a natural resource, existing in the earth’s crust, plants, animals, and humans. Copper is antimicrobial and does not pose the same risks that plastic pipes do ie, VOCs, unknown contaminants, & AOC growth. With that said, copper has its own problems.
According to the EPA copper can “leach into water primarily from pipes, but fixtures and faucets (brass), and fittings can also be a source.” The EPA also explains that, “the amount of copper in the water depends on the types and amounts of minerals in the water, how long the water stays in the pipes, the water’s acidity, and its temperature.”[1] Over consumption of copper can lead to nausea, gastrointestinal problems, liver damage, and kidney disease, amongst others. [2]
The EPA has limited the amount of copper leaching into drinking water to 1.3ppm.[3] Water treatment plants have added corrosion inhibitors such as fluoride to prevent copper pipe deterioration.[4] Additionally new legislation has mandated potable water pipes to contain less than 0.25% of lead, making copper piping safer than it was before.
Nevertheless, due to the fact that copper has more potential to leach into the water when it is idle (more than six hours), one should run the drinking water for 30-60 seconds before consuming.[5] Additionally, according to the Minnesota Department of Health, hot water dissolves water more than cold water. Thus if you need hot water for cooking, you should heat cold water over the stove rather than getting it directly from the faucet.
According to the Action Water District “after the initial leaching” of copper pipes, “the inner surface of the pipes forms a hard surface that should reduce further leaching.”[6] However, as of now, there has not been a fool-proof way to prevent copper from entering the pipes from within a home.[7] As a result there are different treatment options available such as reverse osmosis, ultra-filtration distillation, and ion exchange that one should consider.[8] The CDC recommends getting your pipes tested by a licensed professional to ensure that copper levels do not exceed safety levels. Conclusion
Unfortunately we do not currently have pipes that are 100% safe. As a result we must choose the best options available. After reviewing the research for plastic vs. copper, copper piping appears to be the system that is the easiest to control. Water filtration methods as well as new lead standards help ameliorate heavy metal toxicity risk. We do not have enough information on the dangers of plastic piping. Studies have shown alarming evidence of VOC presence, unknown contaminants in drinking water, and Assimilable Organic Compounds that can lead to deleterious bacteria. There are too many question marks to adequately enact safety precautions and therefore plastic piping cannot be fully trusted.
Sources on how to make plastic and copper piping safer are welcomed. The more we work towards a solution instead of defending the status quo, the closer we will be to getting the quality water we want and rely on.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 02 Nov 2016 15:50:03 -0500, snipped-for-privacy@unlisted.moo wrote:

Fine until your water pinholes the copper pipe.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 02 Nov 2016 21:39:12 -0400, snipped-for-privacy@aol.com wrote:

Having worked as a plumber for years, I installed more copper than you've probably even seen. I never had any leaks. There was one rural home that I worked on, which had copper leaching. I first noticed that when I saw green staining in all the sinks. Cutting apart the pipes showed how little of the pipes were left (after about 12 years). A water test revealed a very high acidic water, and a lot of other problms with the well, such as bacteria and nitrates. I told the homeowner about the contaminated well, and that his pipes were being "eaten" by his acidic water, and recommended a new well, and completely new pipes afterwards. Then I just patched up what was leaking, and it was up to him to do what was needed.
Copper dont develop pinholes unless the water is extremely acidic, there was a flaw in the pipe, the pipes freeze, or a nearby lightning strike surges thru a copper water pipe system. Yea, I did run across a place where lightning wiped out a guys electrical system, and blew a pin hole right thru a copper elbow, where it was within an inch from an electrical conduit. The lightning needed to go to ground, and it did. That couduit had a burn mark on it too.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 11/2/2016 7:45 PM, snipped-for-privacy@unlisted.moo wrote:

The house I lived in for 30 years had copper pipes and never a problem. (And it was 10 years old when I bought it.) My current house has plastic pipes and I've also had no pipe problems in 16 years. However I did have one elbow's solvent cement give out to produce a pinhole sized stream. But that was likely a one time installation problem since no other joints have since given out (knocks on wood).
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 02 Nov 2016 21:45:35 -0500, snipped-for-privacy@unlisted.moo wrote:
>I told the homeowner about

A new well? What in another county? That is going to be a long pipe. If the well water sucks, another well will probably get the same water.
Across the river from me in Cape Coral, there was a huge problem with pin holed copper pipe about 25 years ago and the pH was over 7 according to the city water department. I am not sure they ever got a resolution. The pipe company pointed at the electric company, the electric company said it was bad water and the city water people said it was defective pipe. They replaced the copper with plastic and the problem went away.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 03 Nov 2016 01:56:06 -0400, snipped-for-privacy@aol.com wrote:

The well on that property was something like 35 ft deep. The land within 1/4 mile away was a swamp. Speaking with the guys who did the water tests, there was a large rock formation about 15 feet below the surface, and the small basement in that house needed TWO sump pumps, bcause the water table was so high that after every rain, those pumps ran continuously. It's pretty obvious where that water was coming from (surface water from the swamp). The wells of neighbors were all around 300 feet deep, far below that rock formation.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thursday, November 3, 2016 at 1:56:18 AM UTC-4, snipped-for-privacy@aol.com wrote:

Not necessarily. You could drill a new well to a different depth into a different aquifer and get totally different water. For example, around here a lot of people have problems with iron in irrigation wells. It stains sidewalks, siding, orange brown. A friend was having a new irrigation well for a new house put in and I helped him do some research. Most well drillers want to go to ~100 ft, because that's where the aquifer with plenty of water is. Problem is, that's where the rust is too. We found a driller that said in the specific area they can go to just 50 ft, get enough water and it's usually iron free. So, that's what he did and it worked. He has no rust, his neighbor's places are a mess.
Beyond that, there is another major aquifer at 180 ft, that also has no iron. That's where the well at my parent's house tapped into. It was artesian too. So, I think in many cases you could drill a new well to a different depth and solve your problems.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I got copper probably over 50 years old. Just added a T. I looked at that at Home Depot. I don't think they were that thin years ago.
Greg
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.