When you purchase a gallon of milk at a grocery store, are you confident that you actually receive what you pay for? How do you know how much milk is in the jug? You know because you purchased milk using a uniform standard of measure, the U.S. liquid gallon, established by a governmental entity, the National Institute of Standards and Technology. These standards and testing against those standards, are key to consumers being confident that they are receiving what they are paying for while at the grocery store. The application of standards and testing is just as important in purchasing drinking water filters. It is the only (3rd party) objective means for the end customer to validate a drinking water filter product performance claims. There are countless drinking water filters and systems available in the market (especially Amazon), they include, filtered water bottles,  whole house water filtration system, water filter pitcher or jugs, point of use water filter system, and conclusive product test results support the consumer’s ability to evaluate and differentiate among them. 

Water filter testing conducted by a reputable and independent 3rd party testing laboratory is the only way to ensure unbiased test results. In the complex sciences of chemistry testing and toxicology testing that are applicable to evaluating the quality of tap water, awareness of the details behind the test results is critical to truly understanding a product’s capabilities. You cannot simply rely upon an Amazon listing or manufacturer claim; you must dive deeper and demand test results. The focus of this article is on identifying the standards that apply to the products that are commonly utilized for filtering tap water at the point of use, and on what is behind the standards that make standards compliance so important. 

This article also outlines the testing process employed by the recognized leaders in testing for the water filtration industry, NSF/ANSI, IAMPO, WQA (Water Quality Association) Standards. This article also describes how a leading drinking water filter manufacturer, Epic Water Filters, employs internationally recognized standards and independent testing to help consumers evaluate and compare the company’s products to other brands in the market.

Safe Water Drinking Act: 1974

The Safe Drinking Water Act originally was passed by the United States Congress in 1974 to protect the public's health by regulating the nation’s public tap water supply. The law was amended in 1986 and 1996 and requires many actions to protect our national drinking water and its sources: rivers, lakes, reservoirs, springs, and ground water wells. Safe Drinking Water Act authorizes the United States Environmental Protection Agency (EPA) to set national health based standards for drinking water to protect against both naturally occurring and man made contaminants (like chemicals, pesticides, herbicides, etc.) that may be found in our tap water. The EPA, States, and public water utilities then work together to make certain that these standards are met and that the public is notified of testing. Founded in 1918, the American National Standards Institute (ANSI) is a not-for-profit organization serving as the official U.S. representative to the International Organization for Standardization and the United States National Committee, the International Electro-technical Commission (IEC). 

ANSI accredits and coordinates hundreds of companies and committees that develop standards for approval as American National Standards based in part on evidence of due process and consensus. ANSI provides the criteria and procedures for achieving due process and determining consensus, as well as other requirements for the development, approval, maintenance and coordination of American National Standards. 

These ANSI criteria and requirements are accepted by each accredited standards developer as a condition of accreditation. NSF International (NSF) is one such ANSI accredited organization (Accreditation ID 0216). NSF was founded in 1944 as an organization devoted to public health safety and protection of the environment. Today, NSF is the leading global, independent third-party certification and testing organization for products that affect water quality and food safety. NSF is recognized as the leading authority in the development of consensus, establishing national standards that bring together experts from the regulatory, manufacturing, academic, scientific research, and consumer industries. These comprehensive standards provide the basis by which product manufacturers can demonstrate the quality, reliability and performance of their products, and through which buyers, consumers and health officials can be assured of their safety and benefits. 

The NSF Drinking Water Treatment Units Certification Program for Point-Of-Use (POU) and Point-Of-Entry (POE) systems and components was first established in the early 1970s, beginning with the adoption of the first NSF Drinking Water Treatment Units Standard in 1973. Based upon Maximum Contaminant Level (MCL) standards established by the EPA, and working within the auditing framework defined by ANSI, NSF sets the standards for compliance and testing for drinking water filters and systems. Today, a total of seven NSF Drinking Water Treatment Units Standards have been adopted, to which hundreds of companies have certified thousands of POU and POE systems and components used around the world to improve and protect drinking water quality. 

At a regional level, a limited number of states enforce their own compliance standards for drinking water systems sold within the state. States with their own standards include California, Colorado, Iowa, Massachusetts, and Wisconsin. In most instances, states will recognize NSF certification as acceptable proof of drinking water system performance. NSF also is an active participant in testing and certification at the international level. Countries throughout the world are developing and adopting standards for the evaluation of POU and POE drinking water treatment units. For example, the European Committee for Standardization (CEN) has been developing such standards, also referred to as European Norms, for all of Europe.

Tap Water Filter NSF/ANSI Standards in the USA

What does NSF 42 mean? 

•  NSF/ANSI Standard 42 covers point of use and point of entry systems designed to reduce specific aesthetic or non-health-related contaminants (such as chlorine, taste and odor, and particulates) that may be present in public or private drinking water. The scope of NSF/ANSI Standard 42 is to establish minimum requirements for material safety, structural integrity and aesthetic, non-health related contaminant reduction performance claims. The Standard applies most commonly to carbon filtration, but it also applies to other filtration media such as ceramic filters. It’s worth noting that a device may be certified under this and other NSF/ANSI Standards for specific contaminant reduction (e.g., chlorine) by meeting just the minimum level of reduction required by the Standard, not necessarily by removing all of the contaminant present in the source water. With regard to particulate reduction, several classes are used to define the level of particulate reduction, ranging from Class VI for those devices removing coarse particulates of 50 micrometers and larger, to Class I for drinking water treatment units that reduce the smallest submicron particles (i.e., 0.5 to 1.0 micron). 

What does NSF 53 mean? 

•  NSF/ANSI Standard 53 addresses point of use and point of entry systems designed to reduce specific health-related contaminants that may be present in public or private drinking water. NSF/ANSI Standard 53 establishes minimum requirements for material safety, structural integrity, product literature, and health related contaminant reduction performance claims. The most common technology addressed by Standard 53 is carbon filtration, and the standard includes both point of use and point of entry water filter products. Some products fall under the scope of both Standards 42 and 53 because they claim a combination of aesthetic and health claims. 

NSF tests and certifies under Standard 53 if a filter system reduces a significant amount of a specific harmful contaminant from drinking water. Such hazardous contaminants may be microbiological (including filterable cysts), chemical (including disinfection byproducts, pesticides, herbicides, and insecticides), or particulate in nature. NSF may certify that a drinking water treatment units may be effective in controlling one or more of the health effects contaminants. By carefully reviewing the performance data sheet for a product, you will be able to determine whether the device is effective in reducing many pollutants or just a few. 

Also Read: Solid Carbon Block Filters vs. Granular Activated Carbon Filters

Another consideration in evaluating performance claims is to be aware of the role a Performance Indication Device plays in NSF product certification. A Performance Indication Device measures the actual water usage and notifies the consumer when it is time to replace the filter cartridge. A product manufacturer may incorporate a Performance Indication Device into the drinking water system to be able to certify the same system with a higher capacity. It should be noted that a drinking water filter with a Performance Indication Device actually is tested to 120% of the capacity claimed. Without a Performance Indication Device, the filter is tested to 200% of the capacity claimed. In both instances, actual performance is the same. There are several other NSF Drinking Water Treatment Units Standards applicable to water treatment that rely upon technologies other than filtration. 

What does NSF 44 mean? 

• NSF/ANSI Standard 44 – Applicable to water softener systems designed for hardness reduction and health claims. Standard 44 establishes minimum requirements for the certification of residential cation exchange water softeners. The scope of Standard 44 includes material safety, structural integrity, accuracy of the brine system, product literature, the reduction of hardness, and the reduction of specific contaminants from a known quality water source. The most popular claims made under Standard 44 are barium reduction, radium 226/228 reduction, and softener performance.

What does NSF 55 mean? 

• NSF/ANSI Standard 55 – Applicable to systems utilizing ultraviolet (UV) light to provide disinfection. Standard 55 establishes minimum requirements for the certification of UV systems. The scope of Standard 55 includes material safety, structural integrity, product literature, and UV performance. UV systems are categorized either as Class A (delivers minimum 40 mJ/cm2 UV dose and has an alarm) or Class B (delivers minimum 16 mJ/cm2). Systems may be POU or POE. Class A systems may claim to disinfect water that may be contaminated with pathogenic bacteria, viruses, Cryptosporidium, or Giardia. Class B systems may claim to reduce normally occurring nuisance microorganisms. 

What does NSF 58 mean? 

• NSF/ANSI Standard 58 – Applicable to systems employing reverse osmosis technology to address total dissolved solids (TDS) reduction and health claims. Standard 58 establishes minimum requirements for the certification of POU reverse osmosis systems. The scope of Standard 58 includes material safety, structural integrity, product literature, TDS reduction, and additional contaminant reduction claims. These additional contaminant reduction claims may include the reduction of cysts, barium, radium 226/228, copper, hexavalent and trivalent chromium, arsenic, nitrate/nitrite, cadmium, and lead. 

What does NSF 62 mean? 

• NSF/ANSI Standard 62 – Applicable to distillation systems designed for TDS reduction and health claims. Standard 62 establishes minimum requirements for the certification of POU and POE distillation systems. The scope of Standard 62 includes material safety, structural integrity, product literature, TDS, and additional contaminant reduction claims. 

What does NSF 61 mean? 

•  NSF/ANSI Standard 61 applies to drinking water treatment products, but it is focused at the component level rather than at the system level like the other Standards. Standard 61 typically is referenced in relation to material extraction testing conducted for municipal drinking water system components. Components certified to meet Standard 61 have been tested for material safety and, if applicable, structural integrity, but not for aesthetic and/or health claims.