NSF Certification of UV Water Treatment - Is it Important?

Posted by
Colette McCullough

Is NSF Certification of UV Systems Important?

In the United States, almost every product in a commercial kitchen is NSF certified. For example, freezers, sinks, ovens, ice makers, and cutting boards must all be NSF certified in a commercial kitchen. 

These standards ensure quality and safety in not only in restaurants and cafeterias, but in many other industries, as well.

What Does NSF Mean?

NSF standards are widely accepted by government regulatory bodies and many companies due to the thorough product testing required for a product to receive NSF certification.

The mission of  NSF International (formerly the National Sanitation Foundation) is to protect public health and exists to provide third-party testing and validation of products available to the public. 

NSF Certified UV Water Filter Systems

In regards to  UV water treatment, the NSF has established two certification classifications for NSF/ANSI 55 so that UV water treatment system manufacturers can verify their water disinfection claims.

For example, we carry UV water disinfection systems manufactured by  VIQUA

When a UV system is NSF certified, it means the UV system complies with the strict standards and procedures imposed by NSF including extensive product testing and material analyses. As the manufacturer, VIQUA is also subjected to unannounced plant inspections and regular re-testing of our products to maintain the NSF certification. It is not a one-time event but an ongoing review process. NSF certification is recognized by regulators at all levels from local and state to federal and international. The VIQUA line-up includes several UV systems that are NSF certified. You’ll see other industry markings on VIQUA products as well. These include CE and UL as market appropriate. Both of these communicate that the product is assessed before being placed on the market and meets safety, health and environmental protection requirements.( VIQUA statement on NSF Certification)

NSF Certified Class A Systems:

Class A systems (40 mJ/cm2) are designed to disinfect and/or remove microorganisms, including bacteria, viruses, Cryptosporidium oocysts and Giardia cysts from contaminated water to a safe level. These systems are not intended for the treatment of water that has an obvious contamination or intentional source, such as raw sewage. Class A systems are not intended to convert wastewater to drinking water. The systems are intended to be installed on visually clear water (not colored, cloudy or turbid).

While both certifications for Class A and B are rigorous, Class A systems include UV dosage and fail-safe requirements that go above and beyond those of Class B systems.

See Class A certified systems we carry

NSF Certified Class B Systems:

Class B Systems (16 mJ/cm2) are designed for "supplemental" bactericidal treatment of public or other drinking water that has been deemed acceptable for human consumption.

Basically, Class B systems may claim to reduce normally-occurring, nonpathogenic nuisance microorganisms, but cannot claim to disinfect microbiologically unsafe water.

See Class B certified systems we carry

Similarities and Differences Between NSF Class A & Class B

Both Class A and Class B systems share strict requirements for safety of materials in contact with drinking water and for structural integrity of systems connected to a pressurized water supply. Both must include flow restrictors to assure that the UV dosage cannot drop below that which results from testing. Class A systems, however, require a higher UV dosage. ( WCP Online)

In addition, NSF/ANSI 55 requirements specify that Class A ultraviolet systems incorporate an alarm or fail-safe element into their design. Therefore, all Class A systems include sensors that provide an audible and visual indication that the system is not performing to Standard. In fact, during the Class A certification process, all UV systems are tested to ensure the UV sensor and alarm perform properly even during low-dosage conditions.

Although Class B systems are not required to have a UV sensor, if a class B system is equipped with a sensor, then it must meet the necessary requirements.

We are proud of the industry-leading  VIQUA UV systems we carry here at ESP Water Products. We feel confident these systems have been submitted to the most rigorous certification standards in our industry. Because of careful testing, quality manufacturing, and industry-leading warranties, we continue to offer VIQUA UV systems to our ESP Water Products customers.

For a complete list of NSF water treatment standards, visit If you have any questions about NSF testing/certifications, please call our customer support team at 877-377-9876.