NSF ANSI 58:2020 pdf free download – Reverse Osmosis Drinking Water Treatment Systems
4.1.1.1 Materials in contact with drinking water shall not impart levels of target compounds or tentatively identified compounds (TICs) that exceed the total allowable concentration (TAC), maximum contaminant levels (MCL), or maximum acceptable concentration (MAC) criteria specified in NSF/ANSI 61 Annex D, Table D.1 . Any extractable contaminants not listed in the referenced tables shall be reviewed and shall not exceed criteria developed in accordance with NSF/ANSI 61 Annex A. 4.1.1.2 TIC identification and quantitation shall be conducted in accordance with Section
4.5.1.2. Additional TIC identification and quantitation should be verified using a standard of the compound in question or an alternate approved analytical method. Additional TIC identification and quantitation is recommended when the contaminant is a health risk or when the “probability-based matching” process in Section 4.5.1 .2 is inconclusive. When possible, the product manufacturer should assist and support the testing laboratory in the identification of a standard for the compound and an appropriate analytical method, if applicable, so that confirmatory identification and quantification can be performed. If a standard and an adequate alternative analytical method are not available to verify the identification and quantitation of the compound, the TIC shall be evaluated according to Section 4.5.1 .2. NOTE — Manufacturers may not be privy to formulation information, so they may not be able to assist a testing laboratory to identify a standard for the compound that extracted. Refer to Section 4.5.1 .2 when the manufacturer does not have material formulation information.
4.1.1.4 Whole-system or component assembly extraction testing may be waived if components, when separately tested, meet the requirements of this Standard and are assembled in a manner that does not introduce any new components or materials, increase the surface area-to-volume ratio of previously evaluated components, or present potential concern based on cumulative factors. The reported extractable concentrations for components shall be arithmetically added to ensure that the whole-system or component assembly meets the allowable levels in accordance with Tables 4.1 , 4.2, and 4.3, and with Annex A, D, and E of NSF/ANSI 61 .
Components other than membrane elements shall follow the same process, but shall be flushed according to the manufacturer’s instructions prior to each 24-h exposure. A minimum sample volume of 2 L shall be collected at each sample point. If the water holding volume of the product is greater than 2 L, the entire volume shall be collected in a suitable collection vessel, and a 2-L subsample obtained from this volume. If the water holding volume of the product is less than 2 L, sufficient samples shall be exposed to provide the required 2-L volume of extractant water. Samples collected shall be composited and analyzed in accordance with Section 4.4.1 . Membrane elements shall follow the same process, with the recovery set at the manufacturer’s specification through the use of reject flow control. One membrane element shall be exposed in a suitable housing, with a 2-L sample drawn as product water after each 24-h exposure. The initial exposure shall involve flushing and conditioning in accordance with the manufacturer’s instructions. Subsequent exposure shall involve no additional flushing and conditioning after the 2-L sample is drawn. Samples collected shall be composited and analyzed in accordance with Section 4.4.1.