Comparing Criteria

May 1, 2017
Defining the difference between component & system certification

About the author: Amanda Fisher is business development manager of water systems for UL LLC. Fisher can be reached at [email protected] or 847.664.2473.

My father recently moved into an apartment and acquired a new refrigerator. Uncomfortable with the prospect of inheriting the previous owner’s refrigerator filter, he sought a new one online, specifically one capable of removing copper. He was surprised to find a number of replacement components that fit his fridge. Because he has a daughter with 13 years of experience dealing with the certification of drinking water products, he knew he needed to find a certified filter. However, some had a certification mark with the word “component” under it and some were missing the word “component.” Confused, he called me to clarify the difference.

In the series of NSF/ANSI drinking water treatment unit standards (such as NSF/ANSI Standards 42, 53 or 58), a component is defined as a separate or distinct part of a water treatment system. This includes parts such as housings, tubing, storage tanks, valves, connectors and replacement filters or elements. When pieces of a system are evaluated on their own, the word “component” is placed next to the certification mark.

Components and systems have different evaluation criteria. A drinking water treatment system is required to meet material safety, structural integrity and performance criteria. A component is required to meet material safety criteria and, if it is a pressure-bearing part, structural integrity criteria. A component is not a complete functional system, so it does not need to meet performance criteria.

Product Testing

The material safety test evaluates the materials in contact with drinking water to ensure they do not impart contaminants into the water. For this test, the product is exposed to test water for a time defined by the standard and product type. At the end of the test, the water is analyzed to see which contaminants leached out of the product. Those contaminants must be at or below the levels indicated in the relevant NSF/ANSI standard, which in many cases come directly from the U.S. Environmental Protection Agency or Health Canada.

The structural integrity test evaluates the system to make sure it does not leak when exposed to high pressure or repeated fluctuations in pressure. This is done through hydrostatic and cycle pressure testing.

Performance testing evaluates the system against minimum criteria defined by the standard and requires at least one elective performance claim. The minimum criteria include testing of minimum and rated service flow rates, testing of pressure drop for larger products, and evaluating product design to ensure replacement components are readily removable, waste connections have an appropriate air gap, and the product does not pose obvious hazards. Performance claim testing is done to confirm the product removes the contaminants it claims to remove, such as lead, particulates, cysts or chlorine.

Benefits of Certification

There are benefits to certifying a filter component to an NSF/ANSI drinking water treatment unit standard. If you sell your product to system manufacturers, they are assured your product has been evaluated to the relevant portions of the standard. The system manufacturer potentially can save money on test costs with its certifier and will feel comfortable that the product should pass testing when used inside a system. If you sell your product directly to consumers, it demonstrates that the product will not leak or contaminate the consumer’s water.

For replacement components, a certification mark without “component” wording can be used when it has been tested for performance with the system. In my father’s example, the filters without the word “component” next to the mark were specifically evaluated for use in his fridge, a typical case for an OEM. The ones with “component” wording were evaluated as stand-alone components, and therefore do not have any certified performance reduction claims.

Products certified as components have been evaluated to all applicable portions of the standard. Many of these products do not make reduction claims because they are not evaluated as a system. When they do, the consumer must be aware that the claims these products are making are not certified and may not be backed by third-party test data to industry standards. Contact the manufacturer to find out which kind of data were used to support its claims.

Armed with the new information I gave him on replacement filters and certification, my father found a refrigerator filter that met his needs. He selected a third-party certified product with test data to back up its copper reduction claim and has enjoyed clean water ever since. 

About the Author

Amanda Fisher