By Rick Andrew

The Water Matters column covered developments in this area of emerging compounds and incidental contaminants in February. There have been several noteworthy milestones achieved in this exciting new area since that time, suggesting that an update is due.

Publishing the standard
Most notably, NSF/ANSI 401 Drinking water treatment units–Emerging Compounds/Incidental Contaminants was published in August as an American national standard. At the time of the last update, a major hurdle remaining prior to publishing was successful completion of validation testing of the contaminant reduction test methods in NSF/ANSI 401. Since then, the validation testing has been completed and results were discussed at the May, 2014 meeting of the NSF Joint Committee on Drinking Water Treatment Units. The results were judged to support the validity of the test methods in the standard for active media products. Following the successful validation testing and discussion by the joint committee, there was a re-ballot to the joint committee and also to NSF’s public health oversight body, the Council of Public Health Consultants, to confirm the standard as an American national standard.

Reverse osmosis not yet included
One major change to the standard since the February article is regarding POU RO systems. In February, it was envisioned that NSF/ANSI 401 would include POU RO systems in the scope; however, that has changed. The reason for this is quite technical. Initially, the plan was to use the same contaminant reduction testing methodology currently used in NSF/ANSI 58. The understood contaminant reduction mechanism forming the basis for the legitimacy of the contaminant reduction test methods in that standard, however, is based on either ionic rejection or size exclusion. There was concern expressed by some joint committee members that reduction of emerging compounds and incidental contaminants at trace concentrations by POU RO systems could be due to a mechanism of adsorption on the membrane surface. If the mechanism of  contaminant reduction is adsorption, as opposed to ionic rejection or size exclusion, then a different contaminant reduction test methodology will need to be developed in order to include POU RO systems in the scope of NSF/ANSI 401. With this thought in mind, at the May joint committee meeting it was decided to move forward with publishing NSF/ANSI 401 initially for active media systems only. The joint committee also expressed intent to add POU RO systems to the standard in the future, however. In light of this intent, the joint committee formed a group to begin working on this issue so that in time POU RO systems will be able to be added to NSF/ANSI 401.

First certifications
Also in August, NSF issued the first certifications to NSF/ANSI 401. Initially, there were 56 products from 10 different manufacturers certified. Undoubtedly more will be added in the future as additional manufacturers request testing of their products to this new standard. The current listings can be seen at

Consumer survey reveals concerns and behaviors

A survey of just over 1,000 consumers was completed in August to explore attitudes regarding emerging compounds and incidental contaminants in drinking water. This survey, conducted by an independent organization on behalf of NSF, revealed some interesting insights:

  • 82 percent of consumers report they are concerned about trace levels of emerging contaminants in drinking water.
  • Pesticides and herbicides were the largest concern, followed by prescription drugs, detergents, flame retardants and OTC drugs.
  • Despite these concerns, 33 percent of consumers dispose of prescription and OTD medications by throwing them in the garbage and 19 percent actually admitted to flushing them down the toilet.
  • 28 percent of respondents reported that they bring medications to a pharmacist or clinic for proper disposal.

Details regarding this survey, the methodology and associated results, can be found on NSF’s website at

What’s next?
Clearly, 2014 has seen a tremendous amount of activity in the POU industry related to emerging compounds and incidental contaminants. While it is always risky to engage in predicting the future, there are some strong indications of future activity in this area. They include:

  • Continued consumer concerns. With 82 percent of consumers currently reporting concerns and a significant portion of them still not disposing of medications properly, it is likely that concerns will continue into the future. Additional studies of source water and drinking water will almost certainly reveal more detection of emerging compounds and incidental contaminants in the future.
  • Additional certifications to NSF/ANSI 401. Considering the 56 products certified to NSF/ANSI 401 already, it is unusual to have so much interest in certification to a new standard. Likely there will continue to be more manufacturers and more products certified to the standard in 2015.
  • Expansion of NSF/ANSI 401 to include POU RO systems. With a task group already established by the joint committee, as well as continued consumer concerns, there is a high probability that in the future test methods for contaminant reduction for POU RO systems will be developed and validated so that POU RO systems can be added to the scope of NSF/ANSI 401.
  • Expansion of NSF/ANSI 401 to include additional contaminants. Currently, the standard includes requirements for claims of reduction of 15 contaminants (see Figure 1). The joint committee has discussed many times that the scope is open for expansion to other contaminants as new research is reviewed, new analytical capabilities developed and new consumer concerns revealed. Given the broad range of compounds being detected, this type of expansion is likely.

In retrospect, the decision to include the word Emerging in the title of NSF/ANSI 401 was quite fitting. The opportunity in this area of incidental contaminants and emerging compounds is indeed just beginning to emerge. The emergence of this opportunity will likely be a major theme in developments surrounding the POU industry in 2015 and beyond.

About the author
Rick Andrew is NSF’s Director of Global Business Development–Water Systems. Previously, he served as General Manager of NSF’s Drinking Water Treatment Units (POU/POE), ERS (Protocols) and Biosafety Cabinetry Programs. Andrew has a Bachelor’s Degree in chemistry and an MBA from the University of Michigan. He can be reached at (800) NSF-MARK or email: [email protected]


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