NSF International is a global independent public health and environmental organization that provides standards development, product certification, testing, auditing, education and risk management services for public health and the environment. It has earned ISO 14001 environmental management system certification, which demonstrates the organization’s overall commitment to environmental stewardship.
NSF developed its first drinking water treatment standard in 1973. Today, they test to seven point-of-use/point-of-entry (POU/POE) drinking water treatment standards and have certified thousands of systems and components.
The NSF POU/POE standards address the wide array of drinking water treatment technologies on the market today, including adsorptive medias, ion exchange, reverse osmosis, ceramic filters, pleated filters, ultraviolet (UV), distillation, reduction-oxidation (redox), shower filters and more. Point-of-use (POU) and point-of-entry (POE) systems also include pitchers, faucet mount, counter top, refrigerator, under sink, plumbed-in and sports bottle type filtration systems.
Each NSF Residential Drinking Water Treatment Standard sets thorough health requirements and performance criteria for specific types of products. Contaminant reduction claims can be certified under each standard and can vary according to each water treatment technology capability. Systems that utilize more than one treatment technology may be certified under multiple standards.
How Do Products Become NSF Certified?
To earn NSF certification, water treatment systems must undergo extensive testing to confirm that they meet the strict requirements of American National Standards. In addition to verifying that the system is structurally sound, NSF verifies that:
- The contaminant reduction claims shown on the label are true.
- The system does not add anything harmful to the water.
- The product labeling, advertising and literature are not misleading.
Two NSF standards cover filtration systems: NSF/ANSI 42 addresses aesthetic claims and NSF/ANSI 53 addresses health claims.
NSF/ANSI Standard 42: Drinking Water Treatment Units – Aesthetic Effects
NSF/ANSI Standard 42 establishes the minimum requirements for the certification of POU/POE filtration systems designed to reduce specific aesthetic or non-health-related contaminants (chlorine, taste, odor and particulates) that may be present in public or private drinking water.
The scope of NSF/ANSI 42 includes material safety, structural integrity and aesthetic, non-health-related contaminant reduction performance claims. The most common technology addressed by this standard is carbon filtration.
NSF/ANSI Standard 53: Drinking Water Treatment Units – Health Effects
NSF/ANSI Standard 53 establishes the minimum requirements for the certification of POU/POE filtration systems designed to reduce specific health-related contaminants, such as Cryptosporidium, Giardia, lead, volatile organic chemicals (VOCs) and MTBE (methyl tertiary-butyl ether), that may be present in public or private drinking water.
The scope of NSF/ANSI 53 includes material safety, structural integrity and health-related contaminant reduction performance claims. The most common technology addressed by this standard is carbon filtration.
NSF/ANSI Standard 55: Ultraviolet Microbiological Water Treatment Systems
NSF/ANSI Standard 55 establishes the minimum requirements for the certification of point-of-use/point-of-entry (POU/POE) ultraviolet (UV) systems and includes two optional classifications:
Class A systems (40 mJ/cm2) are designed to disinfect and/or remove microorganisms, including bacteria and viruses, from contaminated water to a safe level. Class A systems may claim to disinfect water that may be contaminated with pathogenic bacteria, viruses, Cryptosporidium or Giardia.
Class B systems (16 mJ/cm2) are designed for supplemental bactericidal treatment of public or other drinking water that has been deemed acceptable by a local health agency. Class B systems may claim to reduce normally occurring nuisance microorganisms.
Reverse Osmosis (RO)
NSF/ANSI Standard 58: Reverse Osmosis Drinking Water Treatment Systems
NSF/ANSI Standard 58 establishes the minimum requirements for the certification of point-of-use (POU) reverse osmosis systems designed to reduce contaminants that may be present in public or private drinking water. Reverse osmosis systems are the only NSF certified systems that reduce fluoride, nitrate, lead and copper.
The scope of NSF/ANSI 58 includes material safety, structural integrity, total dissolved solids (TDS) reduction and other optional contaminant reduction claims. The most common optional claims addressed by NSF/ANSI 58 include cyst reduction, hexavalent and trivalent chromium reduction, arsenic reduction, nitrate/nitrite reduction, and cadmium and lead reduction. Others include Barium, Copper, Asbestos, Perchlorate, Radium 226/228, Selenium, Pentavalent arsenic reduction (Source: NSF Reverse Osmosis Systems Testing)
NSF/ANSI 401: Emerging Contaminants/Incidental Compounds
Treatment systems for emerging contaminants include both point-of-use and point-of-entry systems that have been verified to reduce one or more of 15 emerging contaminants from drinking water. These emerging contaminants can be pharmaceuticals or chemicals not yet regulated by the EPA or Health Canada which include prescription/OTC drugs, new types of herbicides and pesticides and chemicals used as flame retardants and detergents that have been found at trace levels in drinking water. NSF: Emerging Contaminants: DEET, Ibuprofen, Bisphenol A, Carbamazepine, etc.
Add: P.O Box 130140, 789 N. Dixboro Road, Ann Arbor, MI 48105, USA
Tel: +1 734 769 8010
Fax: +1 734 769 0109
Toll Free USA: +1800 NSF MARK (800 673 6275)
Search for NSF Certified Drinking Water Treatment Units, Water Filters: info.nsf.org/Certified/DWTU
A VOC reduction claim by the manufacturer means the system reduces the concentration of all of the following contaminants:
alachlor endrin simazine atrazine ethylbenzene styrene benzene ethylene dibromide (EDB) 1,1,2,2-tetrachloroethane carbofuran haloacetonitriles tetrachloroethylene carbon tetrachloride bromochloroacetonitrile toluene chlorobenzene dibromoacetonitrile 2,4,5-TP(silvex) chloropicrin dichloroacetonitrile tribromoacetic acid 2,4-D trichloroacetonitrile 1,2,4-trichlorobenzene dibromochloropropane (DBCP) haloketones 1,1,1-trichloroethane o-dichlorobenzene 1,1-dichloro-2-propanone 1,1,2-trichloroethane p-dichlorobenzene 1,1,1-trichloro-2-propanone trichloroethylene 1,2-dichloroethane heptachlor trihalomethanes (TTHM) 1,1-dichloroethylene heptachlor epoxide bromodichloromethane cis-1,2-dichloroethylene hexachlorobutadiene bromoform trans-1,2-dichloroethylene hexachlorocyclopentadiene chlorodibromomethane 1,2-dichloropropane lindane chloroform cis-1,3-dichloropropylene methoxychlor xylenes dinoseb pentachlorophenol