Water safety

Rick Andrew takes a look at NSF/ANSI/CAN 61 and the impacts on Regulations and Codes in North America

The NSF/ANSI water standards have certainly had significant impact on North American state and provincial regulations and codes. This impact is primarily based on protection of human health by assuring safety of treatment chemicals, materials, products and parts in contact with drinking water.

NSF/ANSI/CAN 61: Drinking Water System Components – Health Effects is the American and Canadian National Standard for health effects of drinking water system components. It establishes the health effects requirements for the chemical contaminants and impurities that are indirectly imparted to drinking water from products, materials and parts used in drinking water systems from source to tap, including premise plumbing.

Impacts of NSF/ANSI/CAN 61 on Regulations and Codes
Plumbing codes and state and provincial drinking water agencies across the U.S. and Canada require products such as plastic pipes and fittings, faucets, valves, copper plumbing, flexible connectors and other components that contact drinking water to be certified to NSF/ANSI/CAN 61 by an accredited certification organization.

This impact of the standard on regulations and codes was anticipated, and actually intended, at the time of its development back in the 1980s. Prior to that time, the U.S. Environmental Protection Agency (U.S. EPA) had operated an approval program for products and materials in contact with drinking water. The development of NSF/ANSI/CAN 61 was initiated to shift this approval process into the private sector, in a way that is technically rigorous, is cost effective and allows for smooth and transparent approval of new products, materials and technologies.

Development and maintenance of the standard
The standard is a living document, continuously updated due to changes in regulations, technology and other areas, by a joint committee with equal participation from regulators (such as U.S. EPA, Health Canada and state drinking water officials), users (such as water utilities and engineers) and product manufacturers. NSF/ANSI 61 was developed following the American National Standards Institute process, which ensures open consensus with input from all stakeholders. (In April 2019, NSF/ANSI 61 was updated for Canada and published as a National Standard of Canada (as NSF/ANSI/CAN 61) by the Standards Council of Canada, which follows a similar process.)

NSF/ANSI/CAN 61 Requirements
Testing under the standard is quite rigorous, utilizing highly sophisticated laboratory techniques to help assure safety of products in contact with drinking water. A review of the formulations of raw materials, ingredients and the manufacturing process of parts and products is conducted to determine what contaminants might potentially leach into drinking water. This review forms the basis of an analytical summary of contaminants for the laboratory to look for when testing the product.

Products are tested by exposing them to water that is formulated according to the standard to provide enhanced conditions for leaching of contaminants. Separate exposures at pH 5 and pH 10 are used for analysis of metallic contaminants, and a pH 8 test water is used for testing for leaching of organic contaminants. In addition to testing products at room temperature, the standard requires that products intended for hot water use are exposed at either 140° F (60° C) for domestic end use or 180° F (82° C) for commercial hot water systems end use.

Test specimens are pre-conditioned by exposure to the formulated waters prior to collecting water for analysis. Any contaminants detected must be below the allowable concentration established for the specific contaminants, or the product fails the test. Contaminants regulated by the

U.S. EPA or Health Canada are addressed according to the regulatory levels. Non-regulated contaminants are addressed by NSF/ANSI/CAN 61 through a review of available toxicity data using risk assessment procedures established in the standard. Contaminants that have not been studied sufficiently for toxicity are evaluated at a threshold of evaluation (TOE) at three parts per billion (ppb).

Additionally, NSF/ANSI/CAN 61 requires that products must have a weighted average lead content of no more than 0.25 per cent for materials in contact with drinking water, consistent with requirements of the U.S. Safe Drinking Water Act (SDWA).

A performance-based standard allows a clear pathway to regulatory conformance
NSF/ANSI/CAN 61 is essentially a performance-based standard because conformance is largely based on the results of laboratory testing to determine that a product doesn’t leach harmful levels of contaminants, as defined by the standard. The exception is the prescriptive requirement regarding lead content, based on national regulations. This performance-based approach has the advantage of providing a clear pathway for new and innovative materials, technologies and products to meet requirements by achieving successful test results.

By taking this approach with the structure of NSF/ANSI/CAN 61 and using the standard as a basis for regulations and codes, these new and innovative materials, technologies and products can demonstrate conformance to regulatory requirements in a few months. This allows a rigorous and technically sound approval, with these new products being available to end users much more quickly than under possible non-performance based alternative approaches.

Rick Andrew is NSF International’s Director of Global Business Development – Water Systems. NSF International protects and improves global human health. Manufacturers, regulators and consumers look to the organization to facilitate the development of public health standards and provide certifications that help protect food, water, consumer products and the environment.
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