scope:

This Standard covers UV microbiological water treatment systems and components for point-of-use (POU) and point-of-entry (POE) applications. This Standard covers systems which use UV radiation within the range of 240 nm to 300 nm inclusive. Systems are intended to be used under the following specific conditions.

Class A systems

Class A POE and POU systems covered by this Standard are designed to be used for treating microbiologically unsafe water, but do not reduce chemical or inert particulate contaminants. Systems covered in this Standard are designed to inactivate microorganisms, including bacteria, viruses, Cryptosporidium oocysts, and Giardia cysts, from water. Systems covered by this Standard are not intended for the treatment of water that has an obvious contamination or intentional source, such as raw sewage, nor are systems intended to convert wastewater to drinking water. The systems are intended to be installed on visually clear water (not colored, cloudy, or turbid). Systems with manufacturer claims that include components or functions covered under other NSF or NSF/ANSI Standards or Criteria shall conform to the applicable requirements therein.

Class A systems not installed downstream of a device tested for cyst reduction / inactivation in conformance to the appropriate NSF/ANSI Standard may claim Cryptosporidium oocysts and Giardia cysts only. Class A systems installed downstream of a device tested for cyst reduction in conformance to NSF/ANSI 53 or NSF/ANSI 58 may make a general cyst claim when used on untreated surface waters, or ground water, or both, under the direct influence of surface water.

NOTE - Current data support that Cryptosporidium oocysts and Giardia cysts are inactivated by UV treatment.

Class B systems or components

Class B POE and POU systems covered by this Standard are designed to be used for supplemental bactericidal treatment for the inactivation of microorganisms that may be present in drinking water (public or private) considered to be microbiologically safe and of known quality. Systems covered under this Standard are intended to inactivate normally occurring nonpathogenic nuisance microorganisms only.

The Class B system is not intended for the disinfection of microbiologically unsafe water and may not make individual or general cyst claims. Class B systems shall not make microbiological health effects claims. Systems covered by this Standard (Class B) are not intended to be used with water that is microbiologically unsafe or of unknown quality without adequate disinfection before or after the system. Systems with manufacturer claims that include components or functions covered under other NSF or NSF/ANSI Standards or Criteria shall conform to the applicable requirements therein.

Purpose

The purpose of this Standard is to establish minimum requirements for the reduction of microorganisms using ultraviolet (UV) radiation. UV water treatment systems covered by this Standard are intended for water that may be either microbiologically safe or microbiologically unsafe. This Standard also specifies the minimum product literature and labeling information that a manufacturer shall supply to authorized representatives and system owners, as well as the minimum service-related obligations that the manufacturer shall extend to system owners.