NSF Standards

Product Testing & Certification
NSF International continues to gain recognition by consumers, health officials and the drinking water industry as the independent, third-party certifier for the drinking water treatment industry.
It is NSF International that establishes the consensus standards and testing protocol for drinking water treatment devices used by all other testing laboratories. And only NSF provides the consumer complete assurance that the product they purchase which is "NSF Certified" will perform in accordance
with the manufacturer's claim. More consumers than ever rely on NSF testing and certification to evaluate products available on the marketplace. To Provide a meaningful comparison, it is important that the consumer understand the standards which were developed by NSF International, and adopted by many states, for drinking water treatment devices.

NSF has two standards which apply to drinking water treatment devices, as follows;

NSF STANDARD 42
Claims for taste, odor, color and other aesthetic effects, including the reduction of chlorine and particulate matter fall under NSF Standard 42. Several classes are used to define the level of chlorine reduction. The classes are as follows;

1. Taste, odor and chlorine reduction. Chlorine is widely used by municipalities for water disinfection. However, chlorine in water has been shown to produce undesirable taste and odor as well as Trihalomethanes, a known carcinogen. Certified drinking water treatment devices have been categorized into the following categories based on effective reduction of chlorine throughout the life of the device;

CLASS I Reduces chlorine by 75% to 100%
CLASS II Reduces chlorine by 50% to 74%
CLASS III Reduces chlorine by 25% to 49%

2. Particulate reduction.
Particulate matter found in drinking water make the water appear cloudy or turbid. Drinking water systems Certified for particulate reduction have demonstrated, through testing, that they reduce specified sized particles. Drinking water systems are Certified as meeting one of the following categories;

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

NSF STANDARD 53
Claims for the reduction of specific contaminants from drinking water (public or private), such contaminants being considered as established or potential health hazards, such hazardous contaminants may be microbiological, chemical or particulate (including filterable cysts in nature. It is recognized that a unit may be effective in controlling one or more of the contaminants, but it is NOT A REQUIREMENT that it control all of these contaminants. The specific contaminant challenged would be included in the listing under Standard 53. Included under this standard are;

Chemicals and heavy metals:
Includes chemical and heavy metal contaminants such as lead; lindane; 2,4,-D; asbestos; trichloroethane and others.

Volatile organic chemicals (VOCs):
VOCs are chemicals that vaporize easily from water into air. They are delivered from a variety of solvents, insecticides, household cleaning compounds, industrial wastes and underground storage tanks.

Turbidity:
A condition caused by the presence of suspended and/or colloidal matter. Increased turbidity in water also decreases the effectiveness of chlorination or other types of disinfection.

Cysts:
Cysts are capsules resistant to chlorine containing single cell parasites that may cause disease with symptoms of severe abdominal cramping and diarrhea if ingested. The most common cysts are Giardia Lamblia and Cryptosporidium which are excreted by animals. These two cysts are found in drinking water supplies which use surface water as the primary source.

Total trihalomethanes (TTHMs):
TTHMs are most prevalent in chlorinated surface water supplies. Decomposition of leaves, wood, grass and mineral waste can result in the formation of humic compounds. TTHMs form when organic compounds combine with chlorine and have been found to cause cancer.

These chemicals may end up in the drinking water as a result of misapplication of agricultural chemicals, spills or industrial discharge during manufacturing.

In addition to helping the consumer compare the contaminant reduction performance of a drinking water treatment system, NSF Standards also provide the basis for comparing the capacity (service life) of the units and/or their replacement filters as well as the flow rate of the device.