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Use of Additives in Drinking Water Is Subject to Third-Party Certification

Given the U.S. Environmental Protection Agency's authority over drinking water under the Safe Drinking Water Act, one would naturally assume that the agency also regulates the use of additives in drinking water systems and materials used to handle, store, and deliver drinking water. That, however, is not the case.

Instead, a private, non-profit corporation sets the regulatory requirements for many additives used in contact with drinking water through a "voluntary" third-party certification program.

These third-party certification programs, and the transition of the regulation of drinking water additives by the U.S. Food and Drug Administration and the EPA to NSF International, are discussed below. We also provide information regarding the ANSI/NSF Standards under which drinking water additives are certified. Finally, we outline the process for obtaining certification that an additive product complies with ANSI/NSF Standards 60/61.

Third-Party Certification Programs

In many situations, a supplier's declaration that its products comply with the specified requirements of its customer is sufficient to provide product assurance. However, in other situations, customers demand that the products they purchase be certified to comply with particular specifications that are part of a voluntary industry consensus standard or part of a state or local health and safety code. Likewise, some manufacturers find that they can distinguish their products from those of their competitors by demonstrating compliance with such standards or code requirements. As a consequence, third-party organizations were developed to provide these certifications. Certification programs exist for many commercial products such as organic foods, certain color additives, food processing equipment, and plumbing products. Certification is also used for professional credentialing.

In a properly developed certification program, a disinterested, independent party provides written assurance that a product conforms to specified requirements. The third-party certifier may conduct testing to ensure that the product complies with the specified requirements. Rarely will a certifier test every product produced by a manufacturer; instead, the certifier will often conduct initial and periodic follow-up audits of a manufacturer's facility to ensure that quality control procedures are in place, and will conduct regular testing of randomly selected product to ensure compliance with standard requirements.

The impetus for third-party certification may come from various stakeholders. Industry groups may support certification programs to provide oversight of industry members or provide a means of distinguishing their products from substandard products. A certified product may command a price premium because of its demonstrated or perceived quality. Finally, a regulator may decide, based on limited resources or expertise, that it is more cost effective to use a third party to ensure compliance with its regulations.

It was for this last reason that EPA decided to shift the regulation of drinking water additives to third-party certification, which, in this case, has traditionally meant NSF International.

Legal Requirements for Drinking Water Additives

Prior to enactment of the Safe Drinking Water Act, FDA interpreted the Federal Food, Drug, and Cosmetic Act definition of "food" to include drinking water; accordingly, it regulated drinking water additives pursuant to its jurisdiction to preclear food additives. The SDWA, which was passed in 1974, provided EPA with exclusive authority over the safety of public water supplies. After Congress passed SDWA, FDA and EPA agreed that the act implicitly repealed FDA's authority over drinking water. Nonetheless, the agencies decided that FDA would continue to regulate bottled water and water used in food and food processing. FDA and EPA executed a memorandum of understanding in 1979 to document their respective jurisdictions with respect to drinking water.

SDWA provides EPA the authority to establish maximum contaminant levels for substances that may contaminate drinking water. Such substances may occur naturally or through pollution of public water sources. In addition, substances that are added to drinking water directly or indirectly--such as from migration from paints, coatings, or piping in the storage and distribution system--in the course of treatment and transport of drinking water may also be considered contaminants.

Although SDWA does not require that EPA control the use of specific additives to drinking water, it does authorize EPA to provide assistance to states and local water operators by providing advisory opinions regarding the acceptability of many direct and indirect additive products.1 EPA routinely offered such assistance to manufacturers who supplied products to public water system operators by providing its opinion that the products would not contaminate drinking water.

However, in the early 1980s, EPA recognized that the agency could no longer efficiently or effectively respond to the growing number of pending requests for advisory opinions and sought to shift this responsibility to a non-government, non-profit organization. In 1988, EPA officially terminated its program and endorsed a voluntary, third-party certification by a consortium, led by NSF. The consortium also included the American Water Works Association Research Foundation, the Conference of State Health and Environmental Managers, and the Association of State Drinking Water Administrators.

NSF Consensus Standards for Water Additives

NSF worked with consortium members and industry representatives to establish test protocols and guidelines for evaluating products that may contaminate drinking water. Groups of public water system operators, government regulatory officials, product manufacturers, and NSF personnel developed comprehensive standards for direct and indirect additives.

NSF Standard 60 establishes criteria for evaluating potential or known health effects from chemicals used to treat drinking water. Chemicals must be safe when they are used at prescribed maximum use levels and any associated contaminants must be below the maximum allowable levels of the standard.

NSF Standard 61 applies to drinking water system components. This standard establishes minimum requirements for the control of potential adverse human health effects from products that contact drinking water. It covers every material, component, and device used in potable water systems, including source water intakes, the equipment used in water treatment plants, water distribution systems, and all of the pipe, fittings, and fixtures in a building.2 The American National Standards Institute (ANSI) initially approved Standard 61 in 1989.

Other than a prohibition of lead in piping and plumbing fixtures, SDWA does not require that drinking water system components comply with NSF Standard 61. However, state and local governments often require that such components comply with the requirements of the standard. In particular, more than 40 states now require treatment plant equipment and distribution system components to comply with NSF Standard 61, and most U.S. model plumbing codes, which are typically adopted into local building ordinances, reference NSF Standard 61 for plumbing products.

From a manufacturer's perspective, NSF Standard 61 provides a single criteria under which its products need to be evaluated, rather than necessitating evaluation by 50 different states with the possibility of 50 different results. From a regulator's perspective, the state and local governments benefit from a thorough evaluation of products financed through the private sector. Public water system operators no longer have to review chemical formulations or conduct product testing to ensure the safety of treatment chemicals or materials.

The NSF standards are also continually reviewed and updated by the NSF Drinking Water Additives Joint Committee to ensure that the most current technology and information is included in the standard. The joint committee membership provides a balanced representation from industry, government, and user communities.

Third-party certification is not always required. Further, any organization can test products against the ANSI/NSF standard. NSF and Underwriters Laboratory (UL) are two organizations that are accredited by ANSI to certify products against ANSI/NSF Standard 61. Certification for a Drinking Water Additive Product Certification of a product by either NSF or UL entails a multi-step procedure:

  • Application: Manufacturers of direct or indirect drinking water additives submit an application form to the certifying body seeking certification to the applicable standard. For information about the NSF certification program, see Information about the UL program is available at
  • Formulation information: The applicant provides formulation information for the product, including any potential impurities and/or contaminants. Both NSF and UL treat this information as confidential and do not release it to third parties. When necessary, the certification body gathers information from components and/or raw material suppliers.
  • Formulation review: Chemists and toxicologists review the formulation of the product to determine what, if any, analytical testing is necessary to ensure that the product conforms with the standard. The testing required depends on the degree of the toxicological concern for the particular substance. The certifying body will also often be interested in knowing whether a substance complies with applicable FDA regulations.
  • Initial audit: The certifying officials conduct an internal audit of the manufacturing facility to verify the sources of ingredients, raw materials, and components used to produce the certified product. The verification also involves an inspection of the production and storage areas. Samples of raw materials may be collected for qualification testing.
  • Product testing: The certifying body tests the product according to the applicable requirements of the standard. The testing will include an analysis for substances identified in the review by the toxicologists.
  • Toxicology evaluation: Toxicologists evaluate the test report and normalize the results of the testing to reflect the levels "at the tap" and compare the levels to the maximum allowable levels of the analytes in question.
  • Certification: If the product complies with the requirements of the standard, and if any audit deficiencies are corrected, the product is added to the official list of certified products. The manufacturer is then authorized to affix the program certification mark to certified products according to the marking guidelines of the particular certification body.
  • Follow-up services: After the product is listed, the certifying body conducts unannounced audits in each facility that manufactures the certified product. During this visit, the auditors determine whether the product departs from the original formulation or design. In addition, the auditor reviews quality assurance records to ensure that the product is being manufactured in a consistent manner, and will collect samples for follow-up testing. Any deficiencies will be noted and corrective action must be taken for the product to continue to be listed under the program.


1EPA provided the technical assistance pursuant to SDWA § 1442(b)(1), which allows EPA to "collect and make available information pertaining to research, investigations and demonstration with respect to providing a dependable safe supply of drinking water together with appropriate recommendations in connections therewith." See 49 Fed. Reg. 21,004 (May 17, 1984).

2However, it does not provide product performance standards (e.g., pressure ratings, etc.) for equipment used in drinking water systems. NSF Standard 14 provides the performance standards for plastic piping system components.