Historically, the use of infrastructure pipes containing lead to supply water to homes and businesses has been widespread in North America. However, the use of materials containing lead diminished as the detrimental effects of lead ingestion, including brain and kidney damage, were studied. This contamination became a massive concern for the infrastructure pipe industry in the United States as lead levels were discovered, resulting in a race to replace pipes containing lead through the Bipartisan Infrastructure Law.

In the water industry, evaluating lead in all drinking-water components has come to the forefront, and requirements set by the U.S. Environmental Protection Agency (EPA) and standard NSF/ANSI/CAN 372: Drinking Water System Components – Lead Content play a critical role in creating consistent industry guidelines to help protect the public from lead.

Guidelines and Standards

The EPA’s September 1, 2023, deadline for establishing more stringent requirements for mitigating lead content was an important step in combating lead content in drinking water. The requirements are outlined in what is known as the Lead-Free Rule and address point-of-use (POU) drinking-water treatment systems, including under-the-sink filters, pour-through systems, countertop systems, refrigerator filters, reverse osmosis systems, and filters attached to the sink faucet. Per the EPA, every drinking-water component manufacturer selling within North America is required to comply with the rule.

NSF/ANSI/CAN 372 certification is an important tool to help verify that products meet the new EPA requirements. All materials that make up the components of drinking-water filtration systems need to be evaluated for lead content through this standard. NSF/ANSI/CAN 372 combats the potential use of lead-containing materials in drinking-water filtration components and restricts the application of lead as a calculated ingredient in coatings, materials, or components.

Consistent with the Safe Drinking Water Act (SDWA), the standard requires that all materials encountering drinking water do not exceed 0.2 percent maximum weighted lead content for solders and fluxes and 0.25 percent maximum weighted lead content for all other materials. These requisites are enforced by using a formula to calculate the weighted average lead content of a component or system prior to testing. There are detailed testing procedures to confirm lead content percentages and ensure the material suppliers’ chemical compositions are reliable.

NSF/ANSI/CAN 372 is a benchmark to determine a product’s compliance to strict lead requirements, meaning that products certified to the standard provide third-party verification for drinking-water system manufacturers. This is crucial, as product manufacturers rely on suppliers to provide them with safe materials to construct drinking-water systems, yet not all material suppliers are transparent in their material construction. Certification helps protect manufacturers and end-users from suppliers with materials that contain lead and holds certified drinking-water filtration systems and components to the highest standard for low-lead compliance.

How NSF/ANSI/CAN 372 Low-Lead Certification Works

The process of certifying to NSF/ANSI/CAN 372 requires drinking-water filtration systems manufacturers to follow multiple steps. The first is that the manufacturer must provide all product formulation and use information for the system or component. The product formulation information assesses the lead content of the materials. The material formulation evaluation determines what specific testing is needed for the certification. Additionally, to ensure that all material formulations are trustworthy, the certification body conducts an on-site audit to verify that the information provided during the certification application process matches the production records. If the product passes testing, it will earn NSF/ANSI/CAN 372 certification.

After earning certification, annual audits of the manufacturing facilities and periodic retesting of the certified systems are scheduled. These safety measures ensure the drinking-water filtration systems and components continue to meet the low-lead requirements laid out in the standard. Auditing and retesting are essential certification steps in case of company mergers, updates in manufacturing processes, or changes in material suppliers. Through meeting the criteria of NSF/ANSI/CAN 372 certification, water filtration systems and components show compliance with the EPA’s Lead-Free Rule and thus can continue to be sold within the United States.

History of Monitoring Lead Levels

Monitoring lead in our drinking-water systems is not new; however, the monitoring process has adapted throughout the years to protect the public with the most up-to-date science and technology available. Starting in the 1970s, the SDWA was developed to fortify public health protections regarding safe and clean drinking water.

The most wide-ranging application of the SDWA to address lead in drinking water can be found within an amendment created in the 1980s. Per this amendment, the SDWA barred the application of solder, pipes, or flux that did not meet the lead-free standard in public drinking water systems or buildings that provide drinking water for human consumption. During the introduction of the amendment, “lead-free” was identified as solder and flux that contained less than or equal to 0.2 percent weighted lead content, and pipes were identified as lead-free if they contained less than or equal to 8 percent total weighted lead content.

As research advanced on the detrimental health effects of lead, a neurotoxin that can lead to brain and kidney damage, the SDWA adapted to restrict the parameters of components in contact with water intended for human consumption. As part of this adaptation, the SDWA added an amendment that decreased the allowable maximum weighted lead average content for water products, sold or installed for use in public water systems, to 0.25 percent lead.

This history shows that the crisis of lead in drinking water is not new and will remain a persistent concern. The more knowledge the public has on this important topic, the better public health can be protected. There are other safeguards that can be put in place with different water-filtration technologies to further ensure lead is not present within drinking water. The Lead-Free Rule set in place by the EPA for POU drinking-water treatment systems is an important addition to increasing the public’s confidence in the quality of the water being consumed. Fortunately for the public, there are easily understood certifications, such as NSF/ANSI/CAN 372, that provide a transparent standard for the safety of clean drinking water.

About the author Michael Sheffield is a senior technical reviewer for NSF’s Global Water Filtration Division. He has been with NSF for 11 years. Sheffield has a bachelor’s degree from New Mexico State University and a master of science degree from American University.

About NSF

NSF is an independent, global services organization dedicated to improving human and planet health by facilitating standards development and providing world-class testing, inspection, certification, advisory services, and digital solutions to the food, water, health sciences, and consumer goods industries. NSF operates in 180 countries and is a World Health Organization (WHO) Collaborating Center on Food Safety, Water Quality, and Medical Device Safety.

NSF’s Water Division provides risk assessments, testing, inspection, and certification services for the water industry from source to tap. NSF facilitated the development of the American National Standards for all materials and products that treat or come in contact with drinking water to help protect public health and the environment and minimize adverse health effects. In 1990, the U.S. EPA replaced its own drinking water product advisory program with these NSF standards.


Comments are closed.