Consumers may frequently see the following in product literature: “Replacement cartridge for Company A, B, C and D systems,” “Replacement kit is compatible with other water filtration systems,” and “Fits other systems.”

These are common statements among many of the drinking water treatment units (DWTUs) available in the market today, both commercial and residential. It’s tough to imagine how consumers and buyers interpret these statements when they look to purchase a DWTU replacement element. Considering that many of these alternative components aren’t evaluated, certification organizations like NSF International rely on specific policies that clarify how such claims can be advertised. NSF program representatives review literature during the certification process—including the packaging, data plate, installation manual and performance data sheet—to determine if such an issue exists.

Literature requirements
If the replacement element has been certified by NSF and makes statements relating to use in non-certified systems, the product packaging will direct the consumer to a footnote. In the footnote will be a statement that NSF doesn’t certify the performance or material safety of this replacement element in another manufacturer’s system. NSF has a program policy that gives a company two options when they make statements that advertise its replacement element for use in another company’s product:

1. The company can insert the following delineation statement in close proximity to the advertised statement and in the same typeface and print size: “Not Performance Tested or Certified by NSF.”

2. The company can cite the documentation source for the indicated claim(s): “Tested and verified by independent laboratory testing.”

Whether choosing option 1 or 2, if these claims are on the packaging, the delineation statement will need to be on the same panel of the box as the statement that advertises its replacement element for use in another company’s product. The goal of the delineation statement is to prevent companies from advertising, implying or claiming that any non-certified claim(s) are certified by NSF.

Product safety & performance
There are two main reasons why NSF will not allow companies to make these claims. The first is founded in the materials safety evaluation. This is obvious when using a non-certified replacement element in a certified system. One that may be less obvious, however, is interchanging certified components. A material review of Company A’s system and Company B’s system/component were done when these products were individually certified. When using Company B’s cartridge in Company A’s housing, though, an additive review would need to be performed by a toxicologist before the material safety could be validated. It may be that a contaminant from Company A’s housing was also present in Company B’s cartridge, together which exceeds the maximum allowed concentration.

The second deals with performance claims. Company B’s cartridge in Company A’s housing would have a different seal than Company A’s cartridge in Company A’s housing. Companies invest a significant amount of money into the engineering of the seal to ensure there’s no bypass on the system. This is particularly true of those making cyst reduction claims. Slight differences in the interface between the cartridge and housing can have a significant impact on performance. A related concern comes with product modification, a relatively frequent occurrence with DWTUs. An NSF-certified company isn’t required to change the model designation for a product redesign that doesn’t result in a reduction of performance, i.e., capacity and/or flow rate, or when the performance claims are added to the product listing. Therefore, Company A could have made a change in the housing and replacement element during recertification, while Company B’s retrofitted replacement element may not have been updated. When the consumer inserts Company B’s old design into Company A’s redesign, problems could arise.

Options to certification
NSF will not knowingly evaluate, test or certify a hybrid system without the written authorization from both companies. If two companies decide to join in the certification process, NSF will work with them including issues of confidentiality and engineering disclosures. This joint approach can be beneficial for both companies, particularly for those that have different specialties. Company A may manufacture systems with Standard 42 and 53 performance claims while Company B may only certify housings. If the goal is to certify Company A’s cartridge in Company B’s housing, NSF can develop a plan to do that efficiently and with reduced cost.

The NSF program representative will work with the technical manager to develop a subset of performance claims that will need to be performed to validate the seal of the new system. At the same time, NSF’s toxicologists can evaluate the material safety of this new combination. If a Standard 42 claim is desired, it’s unlikely that a test to the full capacity would be necessary to determine that the seal is adequate. In addition, the flow would not be of concern since Standard 42 testing controls the flow to the manufacturer’s flow rate. If Standard 53 claims are desired, a flow rate test will be necessary to ensure that the new combination flows at the same rate or slower than the flow rate of the original system test. In addition to verifying the flow of the new system, a test(s) will be chosen to verify the seal of the new combination. Special documentation can then be made for the plant that will allow the auditor to verify the materials without disclosing ingredients, or the identity of the company’s suppliers or vendors. There are many scenarios, but the main objective is to ensure that information is only disclosed to the appropriate parties.

NSF is also able to provide testing services with two companies that are contemplating certification but are interested in the performance of the hybrid. Once again, NSF would start this project by obtaining written permission from both companies that outlines the scope of the project. NSF can then proceed with testing a product without knowing much about the product. The program representative would only need to know the desired test, flow rate and sampling schedule to offer cost and time estimates. If this preliminary information is acceptable, testing can begin. If not, the program representative and/or technical manager can work with the company to come up with other solutions that will meet the needs of both companies.

Conclusion
Today’s consumer is faced with multiple products when they choose a DWTU that will meet their water treatment needs. It’s important for the consumer to understand that the material safety and reduction claims for a system have only been verified with the manufacturer’s recommended replacement element. NSF has multiple polices in place to ensure consumer safety and product understanding. At the same time, NSF is flexible when partnerships between companies are in the developing stages but performance results are desired. NSF wants to ensure consumers make an informed decision when they purchase a DWTU. At the same time, NSF doesn’t want to interfere with the marketing of a product.

About the author
Tara Sniezek is group leader in NSF’s DWTU department. Sniezek has been with NSF for two years. She has a master’s degree in biology from Oakland University. She can be reached at (734) 913-5726 or email: sniezek@nsf.org