NSF Test Protocol 248 determines the effectiveness of individual water purifiers, making sure they keep water contaminant-free.



In the early 2000s, scientists and engineers in the Department of Defense (DoD) identified a critical need to assess the performance of commercial, off-the-shelf (COTS) individual water purification devices. The emergency water purifiers, which the military issued, were in use since the World War II era. Therefore, they required multiple time-consuming steps, and could in some cases provide a false sense of security - actually failing to produce potable (microbiologically safe for human consumption) water from available water sources, with no indication that was the case.

The recent appearance of a multitude of hand-held COTS individual water purifiers (IWP) was perceived by many to be the solution to the problem. According to the commercial advertising campaigns, these devices were able to produce potable and palatable water from nearly any quality source, and they could keep soldiers hydrated and mission-ready when they did not have access to bulk water supplies. COTS IWPs began to proliferate among deploying units that were able to purchase them.

The Need for Evaluation

None of the IWPs had undergone rigorous DoD evaluations of their effectiveness and applicability to military missions, nor had they been evaluated and approved by any of the Services’ Surgeon Generals. The primary concern for the lack of military and medical endorse­ment was for microbiological contaminants-–bacteria, protozoan cysts, and viruses - –that could rapidly reduce a soldier’s mission readiness through acute gastro-intestinal distress or worse. The concern presented an unacceptable risk to deployed personnel in the eyes of the members of the Joint Medical Field Water Subgroup (JMFWSG) to the Joint Environmental Surveillance Workgroup (JESWG), which was chartered under DoD Health Affairs (HA).

Consequently, a project was initiated to develop a test protocol that all IWPs, intended to be marketed to the DoD, could be subjected to in order to determine their effectiveness in providing microbiological purification. Devices that successfully completed the test protocol could then be used by deployed individuals with a greater measure of assurance that the water they could obtain by using the devices would be of acceptable quality and would not cause acute illness or disease.

NSF Protocol 248

To this end, NSF Protocol 248, Emergency Military Operations Microbiological Water Purifiers has been developed with the firm hope that vendors who want to market their individual water purification devices to the military will use it to develop, evaluate and improve their devices. The ultimate goal is to provide our warfighters the capability to individually produce sustainable quantities of microbiological contaminant-free drinking water, when necessary, from any fresh-water source that may be available to them during deployments.

The U.S. Army Center for Health Promotion and Preventive Medicine (CHPPM) received a grant from the Army Study Program Management Office to develop this protocol during FY 2005. CHPPM coordinated closely with personnel from NSF Intl. who provided guidance and assistance in developing the protocol, as well as oversight in publishing and maintaining it. CHPPM also solicited and received input from many other DoD organi­za­tions, who contributed significantly to the refinement of this protocol, including the U.S. Navy Environmental Health Center, the U.S. Navy Bureau of Medicine, the U.S. Air Force Institute for Operational Health, the U.S. Air Force 311thth Human Sys­tems Wing, the U.S. Army Proponency Office for Preventive Medicine, the U.S. Army Deputy Chief of Staff G-4, DALO-SMT, and the U.S. Army Infantry Center and School. The many efforts of individuals from all of these and other organizations are greatly appreciated.

Protocol P248 was derived and adapted primarily from existing publications of the U.S. Environmental Protection Agency and NSF Intl. It describes the procedures to be used to test individual water purifiers (IWPs) designed to achieve removal or inactivation of microbiological contaminants, including bacteria, viruses, protozoa, and protozoan cysts and oocysts from virtually any fresh water source likely to be encountered by military personnel during exercises and deployments. Execution of this protocol for acceptance of an individual water purifier (IWP) will be administered and monitored by a Government Review Agency (GRA) designated by the Department of the Army Office of the Surgeon General (OTSG). For the purposes of this protocol, and with reference to their use for military personnel in emergency situations, IWPs for microbiological purification are not intended to significantly remove chemical contamination. Claims made by vendors concerning chemical contaminant removal efficiencies are not tested and will not be verified by following this protocol. IWPs, tested using this protocol, are intended only for individual emergency use for short durations as an alternative to the currently fielded iodine disinfection tablets.

A purifier-specific test plan (PSTP) will be developed for each purifier or type of purifier based on this protocol. The protocol is intentionally general in nature so it is applicable to all IWPs, irrespective of physical construction or technology employed. If users find procedures described in this protocol inappropriate or inapplicable to adequately test their particular purifier or technology, deviations can be proposed with documentation, including the reasons for modifying or departing from protocol in the PSTP. Such deviations and departures will be evaluated by the GRA and judged acceptable as long as the level of testing is not decreased, nor the intent of the protocol altered. Test conditions and procedures should be designed to specifically challenge the particular technology under evaluation. The testing of IWP performance involves four sequential steps:
    1.Development and approval of the purifier-specific test plan (PSTP),
    1.Execution of third-party testing in accordance with the PSTP,
    2.Data reduction and analysis, and
    3.Report preparation and information transfer.


This protocol was developed subsequent to, and is based heavily on, NSF P231-Microbiological Water Purifiers. Some vendors of individual water purifiers have already tested their purifiers, either in their own laboratories or by a third party, using NSF P231 or another protocol. Those vendors may submit a request to the GRA that their devices be “grandfathered” into certification. On receipt of such a request, together with a copy of the test plan followed and the evaluation and report or results, the GRA will review the documents and determine the equivalency of the tests performed to those required by this protocol, and at its sole discretion, grant or deny grandfathering. In the case of denial, the GRA will issue a written statement to the vendor specifying the reasons for denial, and in any case, the vendor may retest the purifier(s) using this protocol and/or appeal the denial with rebuttal and/or additional information for the GRA to reconsider grandfathering the certification.


The original version, dated January 2006, is publicly available; however it is important to note that the protocol is under revision at this time. It is anticipated that the new version will be available soon. Reference the CHPPM Web site and NSF Protocol P248 can be located here. For more information, please contact Nikki Beetsch at beetsch@nsf.org or 734-913-5718.

Increasing Use of Hand-Held Water Purifiers

The need to purify natural waters of unknown or variable microbiological quality is a common occurrence among military and non-military government agencies, consumer groups, manufacturers, campers, hikers, as well as others who do not always have access to a treated water supply. In response to this need, entrepreneurs and vendors have developed a number of small, hand-held water purifiers for campers and other recreational users. The performance of these devices, which are intended for military field use, must be thoroughly evaluated to allow informed product selection, and to protect the health of the warfighters that use them.