![]() ![]() Added Normative Annex 6, “Preparation of TOC solution using tannic acid.”.Added a minimum TOC (total organic carbon) requirement (> 1.0 mg/L) to the chloramine test water in Section 7.3.2.6, Influent challenge.”.Updated the minimum air gap requirement for drinking fountain outlets from 2 inches to 1 inch to be aligned with other industry standards and codes.Clarifies the requirements for drinking fountains under the general performance requirements of the standard.In keeping the document current, this revision: ![]() NSF/ANSI 42-2021 revises the 2020 edition of the same American National Standard for filters that limit the aesthetic effects of drinking water treatment units. It also specifies minimum product literature and labeling information for a manufacturer to supply to authorized representatives and system owners. This includes gas chromatography/mass spectroscopy (GC/MS) analysis, structural integrity, and test methods for bacteriological performance. The American National Standard establishes minimum requirements for materials, design and construction, and performance of drinking water systems dealing with aesthetic (nonhealth) effects contaminants in water supplies. The treatment systems addressed by NSF/ANSI 42-2021, which can be either point-of-use (under-the-sink, water pitcher) or point-of-entry (whole house), are designed to reduce specific substances that may be present in public or private drinking water considered to be microbiologically safe and of known quality. Water Treatment Systems Covered by the NSF/ANSI 42 Standard In fact, the systems covered by NSF/ANSI 42-2021: Drinking Water Treatment Units – Aesthetic Effects reduce substances that can affect the aesthetic quality of water (impurities such as chlorine and taste/odor), but they also can add chemicals for scale control or limit microbial growth in the system. Appearance is important for the substance that we literally drink for survival.Īesthetics extends beyond water’s appearance. Setting aside the variance in appearance, odor, etc., in whatever form it takes to occupy 71% of the earth’s surface and an indeterminate amount of the cosmos- water likely arrived on our planet via comets and asteroids-we want this dipolar transparent liquid to be pleasant. We like our water a certain way, especially the type we need to drink. Odds are it shares a striking similarity with the one above. ![]()
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