Through a comprehensive consensus process, the NSF Joint Committee on Drinking Water Treatment Units has developed key standards for evaluation and certification of drinking water treatment units. These include:
NSF/ANSI Standard 42: Drinking Water Treatment Units - Aesthetic Effects
Overview: This standard covers point-of-use (POU) and point-of-entry (POE) systems designed to reduce specific aesthetic or non-health-related contaminants (chlorine, taste and odor, and particulates) that may be present in public or private drinking water.
NSF/ANSI Standard 53: Drinking Water Treatment Units - Health Effects
Overview: Standard 53 addresses point-of-use (POU) and point-of-entry (POE) systems designed to reduce specific health-related contaminants, such as Cryptosporidium, Giardia, lead, volatile organic chemicals (VOCs), MTBE (methyl tertiary-butyl ether), that may be present in public or private drinking water.
NSF/ANSI Standard 58: Reverse Osmosis Drinking Water Treatment Systems
Overview: This standard was developed for point-of-use (POU) reverse osmosis (RO) treatment systems. These systems typically consist of a pre-filter, RO membrane, and post-filter. Standard 58 includes contaminant reduction claims commonly treated using RO, including fluoride, hexavalent and trivalent chromium, total dissolved solids, nitrates, etc. that may be present in public or private drinking water.
NSF/ANSI Standard 44: Cation Exchange Water Softeners
Overview: This standard covers residential cation exchange water softeners designed to reduce hardness from public or private water supplies. Additionally, this standard can verify the system's ability to reduce radium and barium.
NSF/ANSI Standard 55: Ultraviolet Microbiological Water Treatment Systems
Overview: This standard establishes requirements for point-of-use (POU) and point-of-entry (POE) non-public water supply (non-PWS) ultraviolet systems and includes two optional classifications. Class A systems (40,000 uwsec/cm2) are designed to disinfect and/or remove microorganisms from contaminated water, including bacteria and viruses, to a safe level. Class B systems (16,000 uw-sec/cm2) are designed for supplemental bactericidal treatment of public drinking water or other drinking water, which has been deemed acceptable by a local health agency.
NSF/ANSI Standard 62: Drinking Water Distillation Systems
Overview: Standard 62 covers distillation systems designed to reduce specific contaminants, including total arsenic, chromium, mercury, nitrate/nitrite, and microorganisms from public and private water supplies.
NSF/ANSI Standard 177: Shower Filtration Systems - Aesthetic Effects
Overview: This standard covers point-of-use (POU) shower filtration systems, designed to reduce free available chlorine that may be present in potable water (public or private).
NSF Protocol P231: Microbiological Water Purifiers
Overview: Protocol P231 addresses systems that use chemical, mechanical, and/or physical technologies to filter and treat waters of unknown microbiological quality, but that are presumed to be potable.
CSA B483.1: Drinking Water Treatment Systems
Overview: Canadian Standards Association (CSA) developed additional requirements, outside the existing NSF/ANSI standards, to meet plumbing, mechanical, and electrical requirements for drinking water treatment components and complete systems. Products under this scope include POU and POE plumbed systems and POU non-plumbed systems. The regulation will go into Canadian National Plumbing Code in 2010 but provinces can adopt the standard at any time.
For further information about NSF/ANSI standards, including the development process and updates under consideration by the applicable joint committee, please visit the Standards and Publications section of our website.