By Rick Andrew

Once upon a time, laboratory testing of point of use (POU) and point of entry (POE) water treatment products was quite limited. There were not many options for testing at independent laboratories and few manufacturers had the capability to run contaminant reduction tests in their own labs. Product performance was verified through information obtained from the field, from engineering assessments and models and from certification testing.

This approach made certification testing a risky business for manufacturers. Often, manufacturers had no prior lab testing to build confidence that their certification testing would be successful. This environment resulted in significant certification test failures due to a lack of knowledge about how the product would perform when subjected to certification testing, as well as development of products that far exceeded requirements because the manufacturer wanted to be sure they would pass certification testing.

Today, a vast assortment of options and strategies for laboratory testing are available. Laboratories performing certification testing typically also offer non-certification, R&D testing options. More and more manufacturers have increased their own laboratory capabilities to the point where they can perform tests according to the NSF/ANSI Drinking Water Treatment Units (DWTU) Standards. There are options to use independent laboratories that are not affiliated with certifiers.

This expansion of testing options provides great opportunity for manufacturers. The question is, how can manufacturers best utilize these services? What is the best strategy to minimize product development time, select the best options for new products, ensure success when testing for certification and keep testing costs under control? This article will examine these issues and offer some advice for manufacturers facing them.

General approaches to laboratory testing
There is an endless array of possibilities for testing of POU and POE products. However, many fall into some general categories of approaches. Selected based on manufacturers’ goals, specific test plans are developed to best achieve those goals given details of a particular project. These can be roughly described as follows.

Certification testing
All requirements and procedures associated with the appropriate NSF/ANSI DWTU Standard are followed. There are no deviations from procedures in terms of test waters, analytical confirmations, sample points, numbers of test units, laboratory QA/QC, etc. Testing is performed by a laboratory whose results are accepted by the certifier with whom the manufacturer seeks certification. Passing test results will be applicable to certification of the product.

Advantages: Test results can be used for certification. Other products similar in design and configuration to the one tested may be certified using the same test results.

Limitations: Costs and time are reflective of a certification test. No direct comparison of different product configurations can be made.

Certification testing of multiple product options
This approach is the same as certification testing but with a twist. Instead of testing two POU devices for contaminant reduction as required by Standard 53, for instance, four or six are tested. Two or three different product options are tested simultaneously. For a true apples-to-apples comparison, the units can be tested on the same test stand at the same time, with the influent split between all four or all six units (see Figure 1). This eliminates any variability in test conditions and allows a very direct comparison of performance between the product variations.

Advantages: Test results can be used for certification. The best-product option can be selected based on directly comparable results for different product configurations. There can be some cost savings by the use of only one test stand and the sharing of influent analysis across multiple tests. Other products, similar in design and configuration to those tested, may be certified using the same test results.

Limitations: Costs and time are reflective of a certification test.

Testing that is predictive of certification testing but cuts cost.
This approach is utilized as a pre-screening technique prior to implementing a certification testing program. It is used to provide an indication that product development is on track and that the resultant product will pass certification testing. Because it is a pre-screen, some short-cutting techniques can be used to reduce costs and the time required for testing.

There are many different techniques that can be used to do this. The best example for illustrative purposes is short-cutting a Standard 53 arsenic reduction test. Standard 53 requires that batches of test water be created from a recipe of water and reagent chemical additives. For certification purposes, the batches of water must be analytically confirmed prior to use of the test water. This requires rapid turnaround analytical results for 12 different chemical parameters, which leads to significant costs and laboratory time (see Figure 2 for the requirements for pentavalent arsenic reduction test water under Standard 53).

By eliminating the analysis of the batches of test water and just assuming that the batches are within specifications as made, the laboratory can save a great deal of cost and time, which leads to faster, less expensive testing for the manufacturer. Obviously, these results cannot be used for certification because of the short-cutting techniques.

Advantages: Significant cost and time savings result from short-cutting requirements in the Standard. Results are predictive of certification testing.

Limitations: Test results cannot be used for certification. There is some risk that cost-cutting measures may result in a test that is not exactly predictive of a certification test.

Predictive testing of multiple product options
This approach is the same as described in the previous option, but includes the added benefit of testing multiple product configurations. This technique can be very effective for early product development stages when multiple paths are being pursued and manufacturers wish to narrow the options down to the best one. The split-influent technique is a great way to select the best performing product configuration to focus future development efforts.

Advantages: Significant cost and time savings result from short-cutting requirements in the Standard. Results are predictive of certification testing. Choices between product development paths can be made based on performance.

Limitations: Test results cannot be used for certification. There is a small risk that cost-cutting measures may result in a test that is not exactly predictive of a certification test.

Limited duration testing
Standards for non-media based product technologies, such as reverse osmosis (RO), ultraviolet disinfection (UV) and distillation require certification testing evaluations over repetitive operational cycles. Often, a limited evaluation using the test conditions specified in the Standard can be valuable in predicting how the product will perform over the entire duration of the test. This short-duration testing can be done at lower cost and more quickly than conducting the entire test. For example, a UV disinfection system could be tested for just one day of the seven-day protocol, to determine whether its dosage is meeting the requirements of the Standard.

Advantages: Significant cost and time savings result from short-cutting requirements in the Standard. Results are predictive of certification testing. The test can potentially be continued to result in a certification test, if results are favorable.

Limitations: Test results cannot be used for certification, unless testing is continued per the Standard. There is a small risk that limited duration testing may result in a test that is not exactly predictive of a certification test.

Iterative testing variations
Performing a series of limited duration testing that vary individual conditions can lead to an optimization in performance. Water softeners are very amenable to this approach. A manufacturer may be seeking to maximize softening efficiency of a particular product configuration. Softening capacity testing according to NSF/ANSI Standard 44 can be conducted with different cycle times, flow controllers and other optional parts variations to allow a particular control valve, resin tank, bed depth, distributor configuration to produce maximum softening efficiency. Once the most efficient configuration is established, certification testing can be completed on the test unit.

Advantages: An optimized configuration can be developed. Testing can be continued on the optimal configuration for certification. Costs are minimized because only one test unit set-up is required to begin the testing sequence.

Limitations: Testing costs can increase as additional iterations are examined. A quick analysis of the laboratory’s results by the manufacturer is required to assess their optimal configurations and to minimize the testing costs by selecting the best configurations quickly.

Protocol certifications
For technologies or unique contaminant reduction claims not addressed by the NSF/ANSI Standards, it may be possible to develop a protocol for certification. Protocols are formal documents, adopted through a consensus process, similar in many ways to NSF/ANSI Standards. The process does not require a Joint Committee approval, but rather a much smaller scope of peer review. Use of certification marks may be allowed for protocol certifications, depending on the policies of the certifier.

Advantages: New technologies can have their performance established and certified more quickly than a consensus standards development approach would allow. The protocol development process is not as public as a consensus standards process, allowing for stealthier product introductions.

Limitations: Not all laboratories or certification agencies provide protocol development processes. Protocols are not established as American National Standards, leading to the chance that more than one organization would develop protocols for the same scope of products having different methods and criteria. Costs for protocol development are borne by the manufacturer and time to develop a protocol can be several months. These limitations do not apply to existing protocols.

The sky (and your creativity) is the limit
The general approaches presented here describe some of the more commonly used and proven techniques that are available for manufacturers who seek to best utilize POU and POE laboratory testing services to assist them in product development and due diligence. This is by no means an exhaustive list of all the value-added testing programs that can be implemented. Each manufacturer has unique product lines, resources, development needs and markets. For these reasons, the best plan for laboratory testing services will be unique to the specific projects and their manufacturers.

There is no limit to the possibilities except lack of imagination. My hope is that this article will help product development engineers, regulatory compliance professionals, marketing managers and others to start thinking along the lines of possibilities.

As Mark Twain once said, “Fiction is obliged to stick to possibilities. Truth isn’t.” I encourage you to consider the realm of possibilities for laboratory testing, to help you maximize the value you derive from it.

About the author
Rick Andrew is the Operations Manager of the NSF Drinking Water Treatment Units Program. Prior to joining NSF, his previous experience was in the area of analytical and environmental chemistry consulting. Andrew has a bachelor’s degree in chemistry and an MBA from the University of Michigan. He can be reached at 1-800-NSF-MARK or email: [email protected]

 

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