Nov 02, 2006

Narrowing Down the World of Standards

It’s an all-too-common scene for manufacturers seeking to sell their products—a customer inquires about product testing to demonstrate a product’s safety, durability and/or capability before making a purchasing decision. As a result, the sales team tells the engineers to, “Find a lab and get the testing done.”

Finding a lab, however, is just the first step in accomplishing this goal. Once the lab has been located, the lab techs always ask, “What kind of testing do you want?” This is an open-ended question that is difficult to answer in and of itself. The more involved question, however, comes after the engineers have identified the type of testing: “What protocol or standard would you like us to follow?” This question is usually based on conversations with the sales team or the potential customer.

Answering this question requires detailed instructions to the laboratory. In practice, it is easier and probably more accepted by the potential customer to request testing for a recognized standard, where there is one, as opposed to an adhoc protocol. But which standard? There are so many of them.

Water treatment equipment manufacturers may be drawn to the NSF/ANSI standards, but even narrowing down the world of standards to this group can still result in multiple applicable standards.

Don’t despair; the correct standard is the one appropriate to the end use of the product. The technology and the potential customer’s proposed end use dictate the appropriate standard. Read on to see how the NSF/ANSI standards apply based on specific markets and technologies.

Multiple Standards for One Technology

To illustrate one example of different standards for a water treatment technology, let’s focus on ultraviolet (UV) disinfection systems. There are three possible NSF/ANSI standards that could be applied to UV systems:

  • NSF/ANSI 50 - Circulation system components and related materials for swimming pools, spas/hot tubs
  • NSF/ANSI 55 - UV microbiological water treatment systems
  • NSF/ANSI 61 - Drinking water system components health effects

How do you know which is the correct standard for a particular application of UV systems? Each of these standards has a scope, which defines its area of applicability. Figure 1 includes a description of the scope of each of these standards.

Based on a review of Figure 1, the appropriate standard for a UV system would be determined as follows:

  • If the UV system is to be used in a pool, spa or hot tub application, the appropriate standard is NSF/ANSI 50.
  • If the UV system is a point-of-entry (POE) or point-of-use (POU) residential water treatment system, the appropriate standard is NSF/ANSI 55.
  • If the UV system is to be used in a water distribution system, but not POE or POU, the appropriate standard is NSF/ANSI 61.

A Second Example

For a second example, let’s look at reverse osmosis (RO) systems. There are two possible NSF/ANSI standards that could apply to RO systems, as seen in Figure 2.
Figure 2 shows us that the appropriate standard for RO systems would be determined as follows:

  • If the RO system is a POU system, the appropriate standard is NSF/ANSI 58.
  • If the RO system is to be used in a water distribution system, but not POE or POU, the appropriate standard is NSF/ANSI 61.
  • If the RO system is a POE system, then there is no NSF/ANSI standard for it. Cases such as this one, in which there is a gap in coverage of the NSF/ANSI standards, reveal areas where additional standards work could be done, or because of the lack of standards, a protocol for testing the product could be developed and used as the basis for testing.

A Final Example

The final example is water coolers. There is an enormous variety of water cooler products and associated technologies in the marketplace. This results in a variety of potentially applicable standards. Some of these coolers are connected to plumbing, while others are manually filled. Some of them have water treatment, while others do not. The types of water treatment that coolers can have includes filtration, RO and/or UV.

The water cooler example is a bit different from the first two. In the previous examples, we looked at various applications for a given technology. In this case, there is one end-use application (water coolers) that could have different standards applied based on the variety of technologies that could be employed within the system. Figure 3 shows the scope of the standards that could apply.

Because there are so many possibilities, the best way to determine the applicable standards in this case is with a flow chart. (See Figure 4.)

Scope Leads to Answers

Notice that the conclusions reached in terms of identifying specific standards for various applications were all based on a review of the scope of the standards. The scope is included in section 1 of the NSF/ANSI standards, and is often overlooked as simple background information. The reality is that it is very important with respect to the applicability of the standards.

So, next time you are in a position to request product testing, follow this simple two-step process to determine the appropriate standard:

Step 1. Identify the proposed end use of the product for which testing is necessary.

Step 2. Review the scope of each potentially applicable standard to determine which one is appropriate for the technology and the end use.

Of course, if this approach fails and you are still confused, there is still the option to contact NSF for assistance. We are always here to help sort out the complex world of standards and products, and help you determine the appropriate match.

About the author

Rick Andrew is operations manager of the NSF Drinking Water Treatment Units Program. Andrew is a member of the Editorial Advisory Board of Water Quality Products. He can be reached at 800.NSF.MARK, or by e-mail at [email protected].