NSF Standards Explained

NSF International, also known as the National Sanitation Foundation, is an independent third-party certifier for the drinking water industry.

Product Testing & Certification

NSF International has established consensus standards and testing protocols for drinking water treatment devices used by all other testing laboratories. Once a system has become NSF-certified, the consumer can feel confident it will perform up to the manufacturer’s claim. For comparison purposes, we’ve listed each NSF International standard, which has been adopted by many states for drinking water treatment systems.

Here are the different NSF Standards that relate to drinking water treatment and what you need to know about them:

NSF Standard 42

You’ll want to look for NSF 42, which deals with any claims of taste, odor, color, and other aesthetic effects, including reducing chlorine and particulate matter. The classes are as follows:

1. Taste, Odor, and Chlorine Reduction
Many municipalities use chlorine for water disinfection. Unfortunately, this often produces an undesirable taste or odor and Trihalomethanes, a known carcinogen. Certified drinking water treatment devices have been grouped into the following categories based on the efficient reduction of chlorine throughout the system’s life.

• CLASS I – Reduces chlorine by 75-100%
• CLASS II – Reduces chlorine by 50-74%
• CLASS III – Reduces chlorine by 25-49%

2. Particulate Reduction
Water that appears cloudy or turbid is caused by particulate matter found in the water. Drinking water systems certified for particulate reduction have been shown, through testing, that they will reduce specific-sized particles. Drinking water systems are certified as meeting one of the following categories:

• CLASS I – 0.5-1 micrometers (sub-micron)
• CLASS II – 1-5 micrometers (extra-fine)
• CLASS III – 5-15 micrometers (medium-fine)
• CLASS IV – 15-30 micrometers (fine)
• CLASS V – 30-50 micrometers (medium coarse)
• CLASS VI – 50 micrometers or large (coarse)

NSF Standard 44

Water softeners are certified to the NSF 44 standard if they use cation exchange resin that is regenerated with sodium or potassium

NSF Standard 53

Contaminants that are considered potential health hazards, such as microbiological, chemical, or particulate (cysts) in nature, fall under NSF 53. Therefore, any water system that attempts to reduce or remove specific contaminants from a public or private drinking water source will be certified under this standard. It should be noted that while a system may be effective in reducing or removing one or more contaminants, this standard does not require that it control all contaminants. The contaminants included under this standard are as follows:

1. Chemical and Heavy Metals
This includes chemical and heavy metal contaminants such as lead, lindane, 2, 4, -D, asbestos, trichloroethane, and others.

2. Volatile Organic Chemicals (VOCs)
VOCs are chemicals that are emitted as gases from certain solids or liquids. They are delivered by paint thinners, cleaning supplies, pesticides, office equipment, correction fluid, craft materials such as glue, and permanent markers.

3. Turbidity
A cloudiness or haziness to water or other fluid caused by suspended solids that the naked eye can’t generally see. The effectiveness of water disinfection can be decreased by increased turbidity simply because bacteria can become attached to the suspended solid.

4. Cysts
Cysts are pockets that contain single-cell parasites that are very resistant to chlorine. They can cause disease, often accompanied by symptoms such as abdominal cramping and diarrhea. The most common cysts are Giardia and Cryptosporidium, which originate from sewage or animal waste.

5. Total Trihalomethanes (TTHMs)
TTHMs are a byproduct of chlorinated water that contains natural organics. The decomposition of leaves, wood, grass, and mineral waste can form humic compounds. TTHMs form when organic compounds combine with chlorine and have been known to cause cancer.

6. Organic Compounds
Organic compound chemicals can often enter drinking water due to misapplied agricultural chemicals, spills, or industrial discharge.

NSF Standard 55

The NSF 55 covers Ultraviolet Drinking Water Systems. The specific contaminants tested are:

CLASS A – Disinfection
Designed to disinfect water that is microbiologically contaminated but meets all other public health standards. Not intended to treat water that has a confirmed contamination source. This type of system is unable to turn wastewater into safe drinking water. Therefore, this type of system should be installed on visually clear water.

CLASS B – Disinfection
Per the manufacturer’s instructions, this system contains ultraviolet lights that must be replaced periodically. The ultraviolet lamps provide supplemental bactericidal treatment for treated and disinfected drinking water deemed safe for human consumption by the local jurisdiction. More importantly, the system is designed to reduce normally occurring non-pathogenic microorganisms only.

NSF Standard 58

The NSF 58 covers Reverse Osmosis Drinking Water Systems.

NSF Standard 62

The NSF 62 covers Distillation Drinking Water Systems. The specific contaminants covered under this standard are:

1. Arsenic
2. Barium
3. Cadmium
4. Copper
5. Fluoride
6. Hexavalent Chromium
7. Lead
8. Mercury
9. Microbiological Performance
10. Nitrate/Nitrite
11. Selenium
12. TDS (Total Dissolved Solids)
13. Trivalent Chromium

NSF Standard 401

NSF 401 is for both point-of-use and point-of-entry treatment systems verified to reduce at least one or more of 15 emerging contaminants, such as pharmaceuticals or chemicals, that have not yet been regulated by the EPA or Health Canada.

Summary

When purchasing a water filter, it is important to check for NSF certifications to ensure that the filter will reduce the contaminants it claims to.

With all this in mind, check out the Filters Fast Brand if you want a trustworthy filter for your drinking water needs. Thankfully, Filters Fast® Water Filters have been third-party tested to ensure they meet NSF standards.

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