Why do water purifiers need to apply for NSF certification?

Q: Why do water purification devices need to apply for NSF certification?

A: NSF is an internationally recognised and representative testing organisation in the field of drinking water. Water purifiers that obtain NSF international certification must not only pass tests for removing contaminants but also fully meet the following six conditions:

1. Certification of contaminant removal must be tested by NSF in their own laboratory.
2. The water purifier must not add any harmful substances to the water, and the raw materials in contact with water must pass stringent extraction tests.
3. The water purifier must be robustly constructed to meet the requirements for pressure fluctuations in the piping.
4. Advertising, manuals, and labels must not contain any false or misleading statements.
5. The raw materials and manufacturing process must remain unchanged, and suppliers cannot be replaced. Additionally, the product must undergo annual inspections by NSF.
6. Certified products must be retested every five years, with a reapplication and testing fee required each time.

List of NSF Standards:

The NSF Joint Committee on Drinking Water Treatment Units establishes the standards for testing and certifying drinking water filtration equipment. These standards are developed through a rigorous process.

These standards include:

NSF/ANSI Standard 42: Standard 42 encompasses material safety, structural integrity, product information, and the minimum standards for the performance of reducing harmful substances and non-health-related contaminants. The most common claims are for chlorine purification and particulate reduction. The most frequent technology in Standard 42 is activated carbon filtration, and this standard includes both point-of-entry (POE) and point-of-use (POU) products.

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NSF/ANSI Standard 44: Standard 44 establishes the minimum requirements for certification of residential cation exchange water softeners. Standard 44 includes material safety, structural integrity, accuracy of the brine system, product information, and reduction of hardness and specific contaminants (such as radium and barium) from known quality water sources.

NSF/ANSI Standard 53: Standard 53 includes material safety, structural integrity, product information, and the minimum performance requirements for the purification of health-related contaminants such as lead, cysts, and VOCs, as well as many other claimed contaminants. The most common technology used in Standard 53 is activated carbon filtration, related to both Point-of-Entry (POE) and Point-of-Use (POU) standards. Some products fall under both Standard 42 and 53 because they claim reductions for both aesthetic effects and health-related contaminants.

NSF/ANSI Standard 55: Standard 55 establishes the minimum requirements for certification of ultraviolet (UV) systems. Standard 55 includes material safety, structural integrity, product information, and UV performance. UV systems can be classified as Class A (delivering a minimum UV dose of 40 millijoules per square centimetre) and Class B (delivering a minimum UV dose of 16 millijoules per square centimetre). Class A systems are designed to disinfect water contaminated with bacteria, viruses, Cryptosporidium, or Giardia. Class B systems are designed to reduce non-pathogenic nuisance microorganisms.

NSF/ANSI Standard 58: Standard 58 establishes the minimum requirements for certification of Point-of-Use (POU) reverse osmosis (RO) systems. Standard 58 includes material safety, structural integrity, product information, total dissolved solids (TDS) reduction, and additional claims for contaminant reduction. These additional contaminant reduction claims include cyst reduction, arsenic reduction, barium reduction, radium 226/228 reduction, copper reduction, hexavalent and trivalent chromium reduction, nitrate/nitrite reduction, cadmium reduction, and lead reduction.

NSF/ANSI Standard 62: Standard 62 establishes the minimum requirements for certification of POU and POE distillation systems. Standard 62 includes material safety, structural integrity, product information, total dissolved solids (TDS) reduction, and additional claims for contaminant reduction.

NSF/ANSI Standard 177: Standard 177 establishes the minimum requirements for certification of residential shower filtration systems. Standard 177 includes material safety, structural integrity, product information, and chlorine reduction.

Main Information Source: NSF International (National Sanitation Foundation)