THE NSF/ANSI 61 CERTIFICATION PROCESS IS EXTENSIVE AND THOROUGH
PRODUCT INFORMATION AND FORMULATION DISCLOSURE
A manufacturer applying for certification first submits precise information about the design and field use of each product. Product information covers many details, which include engineering schematics, product literature, parts lists, formulation details, bill of materials, and information about the manufacturing process. Products are reviewed and certified at each manufacturing facility. Certification at one plant does not authorize the manufacturer to use the certification mark on the same product at other facilities.
The disclosure of design details and formulation information is required for all water contact materials. The manufacturer must disclose the trade name and source of supply for each wetted material or ingredient used in the product. Manufacturers must also disclose all specialized process steps to determine if the step has a potential health effect impact.
Function and field use conditions of the product are disclosed to ensure a thorough evaluation process and an accurate certification decision. Product function can impact the type of evaluation the product receives. For example, coatings undergo a different evaluation process depending on whether they are applied to a pipe, valve or storage tank.
ALS-Truesdail staff authored the most recent rewrite of Section 3.2 - Information and Formulation Requirements, 3.3 - Identification of Analytes, and 3.3.1 - Formulation-dependent Analysis Selection in ANSI/NSF Standard 61.
COMPREHENSIVE ENGINEERING AND CHEMICAL REVIEW
In order to provide the required comprehensive engineering and chemical review to select the appropriate test samples, ensure your certifying laboratory is equipped with a team of experts. Relevant attributes of the product are evaluated during the review, which includes how the product is used in a plumbing system to the potential for each material to contribute leachates into drinking water. This review includes a chemical by chemical assessment for each material used to determine the potential for each component to contribute a contaminant to drinking water. For products that include variations within a family, (e.g. different formulations, models, or sizes), the engineer determines which product within the family will require testing. When a family of products share similar ingredients, materials, processes, and field end uses; a “worst-case” testing scenarios can often be established, where a single test can be representative of a range of products.
Once the test samples have been selected, the technical team summarizes the required testing in a customized plan, which is used to direct laboratory testing of the product. For Standard 61, the test plan includes a complete set of directions to the laboratory regarding required analyses, exposure water temperature, exposure duration, normalization factors and other details necessary to complete the chemical testing of the product. This thorough review and testing ensures the product is tested to all applicable health effects requirements.
MANUFACTURING SITE AUDIT
CHEMICAL LEACHATE TESTING
After the engineering and chemical review is complete, the samples are requested from the manufacturer or collected in person during the onsite audit. Once the samples arrive in the laboratory, the customized test plan directs the laboratory on how the product will be tested. Products are exposed to the test waters made of various chemistries in a manner that most closely matches their end-use once installed in a plumbing system. The samples then undergo a sequence of water changes, with the length of exposure lasting one to 90 days depending on the product. At the end of the exposure sequence, the water is collected for analysis. To ensure high quality, product exposures also include a control sample and method blank, which are used for background subtraction.
Analytical testing of the leachate water is the next step of the testing process. The water samples are prepared and preserved prior to analytical testing. Standard testing includes analysis for regulated and non-regulated metals, as well as a wide range of semi-volatile and volatile organic compounds. Analytical instrumentation includes utilization of inductively coupled plasma mass spectroscopy (ICPMS), gas chromatography with mass spectroscopy (GC-MS), highperformance liquid chromatography (HPLC), liquid chromatography with mass spectroscopy (LC-MS), and other quantitative analytical instrumentation. Contaminants are identified quantitatively using calibration standards, or by comparison against the NIST spectral library of over 100,000 individual compounds. The level of each compound detected in the leachate water is quantified and then summarized in a test report. Following peer review and final sign off by chemistry lab personnel, the test report is sent to engineers and toxicologists for final evaluation.
TOXICOLOGY REVIEW OF LEACHED CHEMICALS
The next step in the evaluation is to “normalize” the test results to accurately reflect field use conditions of the product. The result of this calculation is intended to reflect the concentration in the water when a person drinks from the tap.
ALS-Truesdail staff were instrumental in establishing many of the normalization parameters currently published in NSF/ANSI 61, including the table in Section 5, which establishes the model to evaluate various sizes of tanks.
After the leachate concentrations are adjusted to reflect “at-the-tap” concentrations, they are compared to the pass/fail criteria as listed in the standard. The use of pass/fail criteria are based on a hierarchy described in Annex A. The pass/fail criteria set by the U.S. EPA or Health Canada are preferentially used when available. In the absence of U.S. EPA or Health Canada criteria, risk assessments published by other entities such as the World Health Organization (WHO) or the International Programme on Chemical Safety may be used. Alternately, with sufficient toxicological data, pass/fail levels can be set by toxicologists from the various certifying organizations. External peer review by the Health Advisory Board following approval by the Joint Peer Review Committee is required prior to incorporation into the Standard. The Joint Peer Review Committee is made up of representatives of all of the ANSI approved certifiers.
The staff toxicologist at ALS-Truesdail has developed hundreds of the risk values reported in NSF/ANSI 61, has peer reviewed hundreds of other substances, and was instrumental in the development of the Health Advisory Board and the Joint Peer Review Committee.
For compounds that do not have criteria and are identified at very low levels, the use of the Threshold of Evaluation Level can be used prior to having a complete risk assessment completed for the compound. After comparing the level of each compound detected against the appropriate criterion, the product may be recommended for certification provided there was successful completion of the audit and all other requirements are met.