Health effect requirements for materials used in potable water applications

By John Gronewold

The United Nations and World Health Organization estimate that the 1.7 million deaths occurring each year from water-borne diseases are preventable through clean water, safe hygiene practices, and adequate sanitation. Many communities in the world do not have the proper sanitation or plumbing systems capable of supplying the necessary potable water. In our communities, the municipality is required to meet the Environmental Protection Agency (EPA) guidelines when supplying our water to homes and businesses. Even though it is important to start with a clean water source, it is equally important to ensure the proper transportation of the water from the source to the end-use point.

Simply put, potable water is clean and uncontaminated water suitable for drinking. Even though all drinking water is potable water, not all potable water is drinking water. Think about it. All water entering a plumbing system has the potential to be drunk by someone at the end of the system. Usually, this is dispensed from a faucet, drinking fountain, or water dispenser on a refrigerator. Similarly, some of the potable water used in our everyday lives is used for bathing, washing dishes or clothes, flushing toilets or urinals, and cooking. Typically for these activities, we do not drink or attempt to drink the water used in these processes, but our plumbing systems do not distinguish the applications when transporting the potable water.

The significance of transporting safe potable water by means of a plumbing system is to protect the health and well-being of the public by utilizing appropriate and proper materials. For the most part, the materials typically used as the main material in the system like copper, brass, chlorinated polyvinyl chloride (CPVC), and polyvinyl chloride (PVC) for cold water, and cross-linked polyethylene (Pex), are deemed safe and have been widely accepted and utilized for years. However, the plumbing system is not installed with these materials solely. The components and appurtenances like faucets, control valves, manifolds, shut-off valves, water heaters, water meters, and other essential devices necessary for the system to function and operate, contain materials that could add contaminates or impurities to the system. For instance, faucets may have neoprene seals or springs that come in contact with the water as it flows through the device. In addition, the joining methods of primers, solvent cements, solders, and fluxes could potentially provide an additional source for reducing the health effects. To ensure the health and well-being of the users; manufacturers, designers and installers must be cognizant of the materials used to convey the water and the potential associated health risks from exposure to the materials.

In the United States, many of the plumbing codes require the materials used in potable water systems have third-party certification to NSF/ANSI Standard 61, “Drinking Water System Components – Health Effects.” This standard, promulgated by NSF International based in Ann Arbor, Michigan; establishes the minimum health effects requirements for the chemical contaminants and impurities that may be directly imparted or leached to drinking water from many items including, plastic materials, plastic and metal pipe, fittings, tanks, protective materials, coatings, linings, liners, joining and sealing materials, adhesives, lubricants, elastomers, distribution devices, valves, pumps, filters, end-point devices, faucets, and control valves, to name a few. NSF 61 addresses the known and unknown contaminants that may cause concerns; many of these have been identified by the EPA and are regulated to limit the allowable levels that the products should contain.

One of the most highly publicized contaminants is Lead and its known consequences for the human body in absorbing this potentially dangerous metal. In the past several years, many laws and regulations have been developed to limit the use of lead in gasoline, paint and especially plumbing products. As with any regulations and requirements, differences abound when looking at individual states and federal requirements concerning lead. The federal government has determined “lead free” devices are those products composed with 8% or less lead content in the material. By this definition, most brasses used in plumbing devices meet this definition. However, the Commonwealth of Massachusetts requires no devices will contain more than 3% lead content, which substantially limits the available brasses. In an attempt to answer these concerns, the plumbing industry does have available some “lead-free” materials using bismuth and selenium as substitutes for lead. Even though the manufacturers have to address manufacturing, quality and costs issues by using the new bismuth and selenium alloys, they are able to create comparable products to the lead-based alloys.

The main difference between the state and federal regulations and NSF Standard 61 is the focus on material content in the plumbing products. The state and federal agencies are concerned with the amount or concentration of an ingredient in the product while NSF 61 is concerned with the leaching of the contaminants from the products. As an example, if a plumbing product contains 8% lead as required in Safe Drinking Water Act, it is possible through the product configuration or design and the manufacturing process used, the lead concentration could leach at a greater amount than the acceptable levels of NSF 61 causing a health effects concern. Conversely, a product could theoretically contain more lead than 8%, but due to its configuration and manufacturing, NSF 61 tests could show the product having a low level of leaching which would allow a product to be acceptable. By providing the requirements for the acceptable levels of known contaminants and establishing repeatable testing procedures to determine the safety of the products, NSF 61 and the plumbing industry has effectively addressed the concerns for protecting the public. However, the state and federal regulations must still be followed.

NSF 61, state and federal regulations, and the plumbing codes do not preclude the use of other materials in the transportation of potable water. The authority having jurisdiction has the right and ability to approve other materials, such as stainless steel or polypropylene. Due to the expense of these materials to manufacture and install them, they are not traditionally used but are acceptable viable alternatives to address an arising need. Should an authority approve the alternate material, a complete evaluation may be necessary to prove its safety in the application, which may include testing and evaluation to the NSF 61 standard.

But just to have the testing performed once is not enough, as stated earlier, the plumbing codes require third-party certification, which is independent testing and acceptance of meeting the minimum requirements of the standard. Beyond the testing, certification agencies have policies that support the testing and detail the process for continued compliance, which includes requirements for periodic testing, notice of changes to the materials, consequences for non-compliance, and manufacturers’ rights for disputing testing failures. Although NSF International is the most well-known for certification of plumbing products, they are not the only organization with the ability to prove the products meet the standard. Other organizations, such as Canadian Standards Association (CSA), Underwriter’s Laboratories (UL), and International Association of Plumbing and Mechanical Officials – Research and Testing (IAPMO – R&T) are just as capable to certify the products to the requirements of the standard.

Not just any company can be a third-party certifier, there has to be oversight to ensure that the certification agency is properly performing the services in accordance to a minimum set of guidelines. For the United States, the American National Standards Institute (ANSI) or American Association for Laboratory Accreditation (A2LA) provide this guidance by accrediting product certification programs to ISO/IEC Guide 65, “General Requirements for Bodies Operating Product Certification Systems.” So, as there is not just one certification company for the products, there are multiple companies that can accredit those certification organizations. Thus, another layer of protection is added to ensure the certification bodies performing the testing and services for the manufacturers and their products are capable and competent in their services.

To ensure the health and well-being of the public, materials are tested and certified for the transportation of potable water. Plumbing companies pay a considerable fee to ensure the compliance of their products meet the requirements of the plumbing codes and state and federal regulations. As an engineer, you can be assured that the products certified by these agencies for health effects meet the requirements necessary to provide safe water to the public.