Water intake pipes – those that distribute water to the faucets and fixtures inside our homes and buildings – are different from a lot of other building materials as they are one of the only materials that come directly into contact with the water that we drink, cook with, and wash with everyday. The materials we use to deliver our drinking water matter to our health and the health of our planet, and HBN recently released a new Water Pipes Hazard Spectrum comparing the impacts of different materials used for interior water intake pipes from a health perspective.
As with most product decisions, tradeoffs exist and must be considered. In the final analysis we favor copper joined without solders, fluxes, or other filler metals in most situations1 over the plastic alternatives. Despite environmental health impacts associated with copper mining and smelting, the evidence suggests fewer concerns than plastic products during the use phase and at the end of life.
The Water Pipes Hazard Spectrum
You can use the HBN Water Pipe Hazard Spectrum to benchmark your current practice and take a step up to healthier options. Products in green categories are typically the better options, whereas products at the bottom of the spectrum, in shades of red, are to be avoided. Those in-between provide intermediate options from a health hazard perspective. Read on to learn more about our guidance, and see our full Pipes Hazard Spectrum for more information.
Note that our research was limited to interior intake pipes, and therefore our findings and recommendations are not intended to be applied to pipes outside of buildings, or pipes that carry waste water out of the building. Our recommendations should be seen as a supplement to, and not a replacement for, the guidance that already exists to address the real issue of contaminated drinking water supplies that many communities face.2 (See end of article for resources on external water pipes.)
Health and Environmental Impacts
The global plumbing pipes and pipe fittings market is worth $11.8 billion USD in 2021 and continues to grow, driven both by new construction and repairs.3 Water intake pipes can be made from copper or a range of plastic materials, and each has pros and cons when comparing the impacts to human health and the environment.
Copper mining can have substantial negative impacts on the surrounding communities. Copper mines can release hazardous industrial waste, such as sulfuric acid, into waterways and into the air. These releases can harm the health of people living nearby, and also can damage nearby crops and corrode buildings.4
One positive characteristic of copper is that it has the potential to be recycled, aligning better than plastic with circular economy principles. Copper pipes are generally made up of 40-80% recycled copper, reducing the need to mine virgin copper, and by extension its environmental impacts.5
Plastic pipes are typically one of the following varieties, each of which having its own environmental impacts:
- Polyvinyl chloride (PVC)
- Chlorinated polyvinyl chloride (CPVC)
- Polypropylene (PP)
- High density polyethylene (HDPE)
- Crosslinked polyethylene (PEX)
All plastic pipes are made from petroleum, carrying forward the fossil fuel’s associated impacts such as carbon emissions during extraction, transport, feedstock refining, and manufacture. A new Shell plant in Pennsylvania, for example, will emit the equivalent of ~ 2.25 million tons of carbon dioxide each year - equal to adding almost 500,000 new cars to the road. Multiply that by the 300 new and expanded petrochemical projects being built in the US alone—primarily for the production of plastic and plastic feedstocks—and you have an enormous environmental issue.6
Product Use Impacts
When drinking water comes into contact with pipes, they can release chemicals into the water. In general, plastic pipes require the use of more chemicals in their manufacture than copper pipes, and some of these chemicals can leach from the pipes or break down into other chemicals that leach from the pipes.7 For example, PVC and CPVC pipes are manufactured with organotin stabilizers that are toxic to the reproductive system and can leach into drinking water.8
While standards, such as NSF International Drinking Water standards, set acceptable levels of certain chemicals that leach out of pipes and pipe components,9 these tests and standards have limitations. For instance, the standards do not consider the combined impacts of multiple chemical exposures that all people experience.10 One additional limitation is that under U.S. federal law, plumbing fixtures and fittings can contain up to 0.25% lead by weight, and solders and fluxes (components used to join pipes together) can contain up to 0.2% lead by weight and still be labeled “lead free.”11 Labeling components as “lead free” that actually contain lead is concerning because numerous authoritative bodies agree that there is no safe level for exposure to lead.12
End of Life Impacts
While most types of pipes aside from PEX are technically recyclable, in actuality copper is the only pipe that both is made of recycled content (40-80%) and is likely to be recycled at the end of its life (40-50% global recycling rate for copper).13 This makes copper a better choice to support a circular economy.
What is the best choice?
While there are real and significant tradeoffs to consider, the best way to avoid hazards throughout the pipe life cycle and to support circularity is to:
- Prefer copper pipes installed without solders, fluxes, or other filler metals. After installation, copper pipes have the fewest health hazards, but many solders and fluxes used to join pipes contain lead and other heavy metals of concern. “Lead-free” solders are still allowed to contain a small amount of lead under federal regulations.
- Avoid using copper pipes if your water supply typically has a low pH (<6.5). Such conditions can be present in water supplied from some private wells, and can cause copper pipes to corrode, releasing copper ions into the water.14 Consuming high concentrations of copper is linked to a number of health effects including liver and kidney damage.15
- If plastic pipes are selected, choose polypropylene (PP) or high density polyethylene (HDPE) over crosslinked polyethylene (PEX). In general, plastic pipes require the use of more chemicals in their manufacture than metal pipes, and some of these chemicals can leach from the pipes or break down into other chemicals that leach from the pipes into water.16 Higher levels of chemicals may leach from PEX pipes than from PP and HDPE. In addition, PEX pipes cannot be recycled into new pipes at their end of life.
- Avoid using polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC). These pipes contain the highest levels of chemicals of concern and they are typically installed using hazardous solvents.
- Prefer products with full disclosure of content through Health Product Declarations (HPDs). In general, water pipes have very poor content disclosure. Encourage manufacturers to fully disclose the content and associated health hazards of water pipes through the industry’s collaborative, user-designed open standard, Health Product Declarations (HPD).
Water pipes carry one of the most valuable resources into our homes, workplaces, and communities. While there are no water pipes free of impacts, HBN’s new Water Pipe Hazard Spectrum provides a simple way to benchmark your current practice and take a step up to the better choices available on the market today. We hope to see continued innovation in the field of water pipes to provide increasingly healthier and safer solutions.
Resources for External Pipes
As stated above, the pipes hazard spectrum does not address water mains and supply lines, but here are some great resources that can help communities navigate this important topic:
 Copper pipes should not be installed when the water has a pH of 6.5 or less. While most public utilities supply water at higher pHs than this, such low pH conditions often occur with private wells and can cause pipes to corrode, releasing copper ions into the water. See https://www.cdc.gov/nceh/publications/books/housing/cha09.htm
 Children’s Environmental Health Network. “Lead in Drinking Water Town Halls – Children’s Environmental Health Network.” Accessed October 15, 2021. https://cehn.org/our-work/lead-in-drinking-water-town-halls; DesignWorksGarage. “Lead-Safe Toolkit for Home-Based Child Care: Lead in Drinking Water.” The National Center for Healthy Housing. Accessed October 15, 2021. https://nchh.org/tools-and-data/technical-assistance/protecting-children-from-lead-exposures-in-child-care/hbcc-toolkit/in-drinking-water/; LSLR Collaborative. “Lead Service Line Replacement Collaborative.” LSLR Collaborative. Accessed October 15, 2021. https://www.lslr-collaborative.org/; Altarum. “Value of Lead Prevention.” Value of Lead Prevention. Accessed October 15, 2021. http://valueofleadprevention.org; US EPA, OW. “Ground Water and Drinking Water.” Collections and Lists, February 20, 2013. https://www.epa.gov/ground-water-and-drinking-water.
 Danwatch. “Impacts of Copper Mining on People and Nature.” Accessed April 30, 2020. https://old.danwatch.dk/en/undersogelseskapitel/impacts-of-copper-mining-on-people-and-nature/; Roberts, Tristan. “Piping in Perspective: Selecting Pipe for Plumbing in Buildings.” BuildingGreen, April 5, 2007. https://www.buildinggreen.com/feature/piping-perspective-selecting-pipe-plumbing-buildings.
 Most leaching studies focus on new materials, but a few are available that look at long-term leaching from pipes. For example, see Connell, Matthew, Alexandra Stenson, Lauren Weinrich, Mark LeChevallier, Shelby L. Boyd, Raaj R. Ghosal, Rajarshi Dey, and Andrew J. Whelton. “PEX and PP Water Pipes: Assimilable Carbon, Chemicals, and Odors.” Journal AWWA 108, no. 4 (2016): E192–204. https://doi.org/10.5942/jawwa.2016.108.0016; Lasheen, M. R., C. M. Sharaby, N. G. El-Kholy, I. Y. Elsherif, and S. T. El-Wakeel. “Factors Influencing Lead and Iron Release from Some Egyptian Drinking Water Pipes.” Journal of Hazardous Materials 160, no. 2 (December 30, 2008): 675–80. https://doi.org/10.1016/j.jhazmat.2008.03.040; and Löschner, Dorit, Thomas Rapp, Frank-Ullrich Schlosser, Ramona Schuster, Ernst Stottmeister, and Sven Zander. “Experience with the Application of the Draft European Standard PrEN 15768 to the Identification of Leachable Organic Substances from Materials in Contact with Drinking Water by GC-MS.” Analytical Methods 3, no. 11 (November 1, 2011): 2547–56. https://doi.org/10.1039/C1AY05471F.
 Adams, William A., Ying Xu, John C. Little, Anthony F. Fristachi, Glenn E. Rice, and Christopher A. Impellitteri. “Predicting the Migration Rate of Dialkyl Organotins from PVC Pipe into Water.” Environmental Science & Technology 45, no. 16 (August 15, 2011): 6902–7. https://doi.org/10.1021/es201552x.
 NSF International. “NSF/ANSI 61: Drinking Water System Components – Health Effects.” 1/5/2016. NSF International. Accessed July 9, 2021. https://www.nsf.org/knowledge-library/nsf-ansi-standard-61-drinking-water-system-components-health-effects; NSF International. “NSF/ANSI/CAN 61 Certification for Your Drinking Water Components.” NSF International. Accessed July 9, 2021. https://www.nsf.org/knowledge-library/nsf-ansi-61-certification-for-your-drinking-water-components; NSF International. “NSF/ANSI 372 Technical Requirements.” NSF International. Accessed July 9, 2021. https://www.nsf.org/knowledge-library/nsf-ansi-372-technical-requirements.
 Wild, Christopher Paul. “Complementing the Genome with an ‘Exposome’: The Outstanding Challenge of Environmental Exposure Measurement in Molecular Epidemiology.” Cancer Epidemiology and Prevention Biomarkers 14, no. 8 (August 1, 2005): 1847–50. https://doi.org/10.1158/1055-9965.EPI-05-0456.
 US EPA, OW. “Use of Lead Free Pipes, Fittings, Fixtures, Solder, and Flux for Drinking Water.” Overviews and Factsheets. US EPA. Accessed July 8, 2021. https://www.epa.gov/sdwa/use-lead-free-pipes-fittings-fixtures-solder-and-flux-drinking-water.; Copper Development Association. “Copper Tube Handbook: VI. Fittings, Solders, Fluxes: Solders.” Accessed August 10, 2021. https://www.copper.org/applications/plumbing/cth/fittings/cth_5join_sod.html.; ASTM B32-20, Standard Specification for Solder Metal, ASTM International, West Conshohocken, PA, 2020, https://doi.org/10.1520/B0032-20.
 American Academy of Pediatrics. “Lead Exposure in Children.” AAP.org. Accessed July 8, 2021. http://www.aap.org/en-us/advocacy-and-policy/aap-health-initiatives/lead-exposure/Pages/Lead-Exposure-in-Children.aspx.;
US EPA, OW. “Basic Information about Lead in Drinking Water.” Overviews and Factsheets. US EPA, February 2, 2016. https://www.epa.gov/ground-water-and-drinking-water/basic-information-about-lead-drinking-water.;
World Health Organization (WHO). “Lead Poisoning and Health.” Accessed July 8, 2021. https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health.
 Glöser, Simon, Marcel Soulier, and Luis A. Tercero Espinoza. “Dynamic Analysis of Global Copper Flows. Global Stocks, Postconsumer Material Flows, Recycling Indicators, and Uncertainty Evaluation.” Environmental Science & Technology 47, no. 12 (June 18, 2013): 6564–72. https://doi.org/10.1021/es400069b.
 National Center for Environmental Health (NCEH). “Chapter 8: Rural Water Supplies and Water-Quality Issues.” and “Chapter 9: Plumbing.” In Healthy Housing Reference Manual. U.S. Centers for Disease Control (CDC), 2009. https://www.cdc.gov/nceh/publications/books/housing/cha09.htm.
 US EPA, OW. “National Primary Drinking Water Regulations.” Overviews and Factsheets. US EPA, November 30, 2015. https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations.; Minnesota Department of Health. “Copper in Drinking Water.” Accessed July 12, 2021. https://www.health.state.mn.us/communities/environment/water/contaminants/copper.html#HealthEffects.
 Connell, Matthew, Alexandra Stenson, Lauren Weinrich, Mark LeChevallier, Shelby L. Boyd, Raaj R. Ghosal, Rajarshi Dey, and Andrew J. Whelton. “PEX and PP Water Pipes: Assimilable Carbon, Chemicals, and Odors.” Journal AWWA 108, no. 4 (2016): E192–204. https://doi.org/10.5942/jawwa.2016.108.0016; Lasheen, M. R., C. M. Sharaby, N. G. El-Kholy, I. Y. Elsherif, and S. T. El-Wakeel. “Factors Influencing Lead and Iron Release from Some Egyptian Drinking Water Pipes.” Journal of Hazardous Materials 160, no. 2 (December 30, 2008): 675–80. https://doi.org/10.1016/j.jhazmat.2008.03.040; Löschner, Dorit, Thomas Rapp, Frank-Ullrich Schlosser, Ramona Schuster, Ernst Stottmeister, and Sven Zander. “Experience with the Application of the Draft European Standard PrEN 15768 to the Identification of Leachable Organic Substances from Materials in Contact with Drinking Water by GC-MS.” Analytical Methods 3, no. 11 (November 1, 2011): 2547–56. https://doi.org/10.1039/C1AY05471F.