WQA & NSF…Who Are They & What Exactly Do They Stand For?

Recently, at a trade show, I was talking with a competitor of ours regarding their equipment versus our equipment and some of the similarities and differences within. After delving into the depths of the conversation weeks later, I realized that there are many, many differences in the equipment. The differences are not necessarily from a physical aspect, but from the inside. The heart of the equipment was like comparing apples to oranges. When I approached him at a later date with my thoughts. His reply was “Brad, what does it matter? Ion exchange is all the same.” I feel that it is time to lay some of the differences out on paper and explain what we were discussing.

Let’s start with third party evaluation.

If you manufacture, sell or distribute water treatment or distribution products in North America, your products are required to comply with NSF/ANSI Standard 61: Drinking Water System Components – Health Effects by most governmental agencies that regulate drinking water supplies. Developed by a team of scientists, industry experts and key industry stakeholders, NSF/ANSI 61 sets health effects criteria for many water system components including:

  • Protective barrier materials (cements, paints, coatings)
  • Joining and sealing materials (gaskets, adhesives, lubricants)
  • Mechanical devices (water meters, valves, filters)
  • Pipes and related products (pipe, hose, fittings)
  • Plumbing devices (faucets, drinking fountains)
  • Process media (filter media, ion exchange resins)
  • Non-metallic potable water materials

This means that if it is a water treatment system in your home, it is required to comply with NSF/ANSI standard 61. This standard is implemented to make sure that you aren’t adding anything that is potentially harmful to your health into the water by installing a filter that is not properly manufactured.

You wouldn’t go to a gas station that had gas pumps that weren’t inspected by a third party organization for accuracy of fuel dispensed, would you? The gas pumps are required to be inspected regularly to ensure that they are dispensing the proper amount of fuel for the dollar you are paying. NSF/ANSI has a myriad of standards that help you with that process as it relates to water softening components as well.

NSF/ANSI 44: Cation Exchange Water Softeners

NSF/ANSI 44 establishes the minimum requirements for the certification of residential cation exchange water softeners designed to reduce hardness from public or private water supplies.

The scope of NSF/ANSI 44 includes material safety, structural integrity, accuracy of the brine system and the reduction of hardness and specific contaminants from a known quality water source. The most common claims addressed by NSF/ANSI 44 are barium reduction, radium 226/228 reduction and softener performance.

In order to meet the strict guidelines set forth by NSF/ANSI 44 all marketing materials and products are required to be evaluated, as a package, before officially becoming certified.

The NSF/ANSI DWTU Standards cover a broad range of products, with each standard addressing a specific technology.

Below is a description of each standard:

NSF/ANSI Standard 42:

The scope of Standard 42 is to establish the minimum requirements for material safety, structural integrity, product literature, and aesthetic, non-health related contaminant reduction performance claims. The most popular claims are chlorine reduction and particulate reduction. The most common technology addressed by Standard 42 is carbon filtration, and the standard includes both point-of-entry (POE) and point-of-use (POU) products.

NSF/ANSI Standard 44:

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, and 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.

NSF/ANSI Standard 53:

Standard 53 establishes minimum requirements for material safety, structural integrity, product literature, and health related contaminant reduction performance claims such as lead, cyst, and VOC reduction, among many others. The most common technology addressed by Standard 53 is carbon filtration, and the standard includes both POE and POU products. Some products fall under the scope of both Standards 42 and 53 because they claim a combination of aesthetic and health claims.

NSF/ANSI Standard 55:

Standard 55 establishes minimum requirements for the certification of ultra-violet (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 POE or POU. 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

NSF/ANSI Standard 58:

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, total dissolved solids (TDS) reduction, and additional contaminant reduction claims. These additional contaminant reduction claims may include cyst reduction, barium reduction, radium 226/228 reduction, copper reduction, hexavalent and trivalent chromium reduction, arsenic reduction, nitrate/nitrite reduction, cadmium and lead reduction.

NSF/ANSI Standard 62:

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, total dissolved solids (TDS) reduction, and additional contaminant reduction claims.

NSF/ANSI Standard 177:

Standard 177 establishes minimum requirements for the certification of residential shower filter systems. The scope of Standard 177 includes material safety, structural integrity, product literature, and free available chlorine reduction.


When it comes to choosing the proper water treatment system, safety is the main concern with most consumers. This ultimately affects anything that comes in contact with your drinking water and the water you bathe in. Efficiency is key when selecting the product that you will be using. When choosing a water treatment product whether it is just for chlorine reduction, or if you are choosing a water softener system, it is important that the assembled product meets NSF/ANSI requirements. Treating the water in your home is a complicated science that should not be taken lightly. The NSF has made standards to protect you, the homeowner, from companies and products that will not cut it.

Another resource to protect you, the purchaser, from a company or product that may not be suited for your application is the WQA (Water Quality Association). The Water Quality Association is a third party organization that certifies individuals and products to exacting standards that parallel or exceed the NSF/ANSI standard. The WQA can help guide you to individuals and companies that are properly trained to treat even the most difficult water in your area. These companies provide you with quality water treatment products that are properly certified and sized appropriately for your individual needs.

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