By Rick Andrew

Material safety is of utmost importance with respect to water treatment products. After all, the purpose of installing a water treatment product is to improve the quality and/or taste of the water. It would be counterproductive, to say the least, if a product intended to improve the water actually leached harmful chemicals into treated drinking water at concentrations significant enough to cause health concerns.

Material safety – a two-step process
The NSF/ANSI DWTU Standards address material safety through two distinct steps:

  • Complete formulations of all wetted materials must be disclosed.
  • Extraction testing must be conducted on the product, with contaminant analysis focused on those contaminants that may leach based on the formulation disclosures.

The concept with this approach is that those ingredients used to formulate or mold the water contact parts, or associated impurities or byproducts, may leach out into the treated water. In order to detect them, a laboratory must know what to look for – hence the formulation disclosure and targeted analytical work.

Extraction testing and selection of analytes is a complicated process worthy of its own discussion. However, this column will focus on step one of this two-step process – the formulation disclosure.

What does the standard say?
The NSF/ANSI DWTU Standards include common wording to describe the formulation disclosure requirement, as indicated in Figure 1. Note that most materials fall outside the exemption categories in Table 3, thus requiring a formulation disclosure. The specific requirements for formulation disclosure include the following:

  • Complete chemical identity of ingredients
  • Percentage by weight of ingredients
  • Ingredient sources of supply
  • Documentation regarding the health effects concern of each ingredient in the material
  • Documentation regarding the suitability of each ingredient for use in potable-water-contact material

Some conclusions about formulation disclosures can be drawn from these requirements:

  • Formulation information must come from the material formulator. This information cannot come from a distributor or molder, as there would be no way for them to know this information – unless they obtained it from the formulator.
  • Sometimes the end product manufacturer is purchasing parts or materials through distributors or molders, so they do not even know who the material formulator is.
  • Obtaining this information can be challenging, especially when end product manufacturers do not know who the material formulator is and when materials are sourced internationally.

The challenges of obtaining formulation disclosures
Achieving NSF/ANSI DWTU Standards product certification is no small feat. There are numerous requirements and challenges that must be met. There can be communication issues with the certifier. There can be a lack of understanding of certification policies. The initial audit can pose challenges. Developing proper product literature can be difficult. The various tests of contaminant reduction, structural integrity and material extraction require a robust and well-engineered product. However, NSF’s experience has shown that the single biggest challenge to certification is obtaining formulation disclosures. The product cannot be certified until all required formulation disclosures have been obtained.

Obtaining the formulation disclosures can be easier or more difficult depending on the level of integration and sourcing strategy of the end product manufacturer, as described in Figure 2. As manufacturers have moved away from highly integrated, US based manufacturing operations and turned to less integrated, internationally based operations, obtaining formulation disclosures has become more difficult, as indicated in Figure 2.

includes an example supply chain. Although this example is relatively straightforward and simple, it requires nine separate steps to work through the chain and ultimately get to the point where the formulation has been disclosed and reviewed by the certifier. Imagine how complicated this can become if the supply chain includes multiple distributors. Consider the implications of having an international supply chain, perhaps in non-English speaking countries. Then consider that a typical end product includes between five and 25 different materials, all of which require formulation disclosures. With all of these confounding factors, it is little wonder that obtaining all required formulation disclosures is the most time-consuming and difficult aspect of achieving product certification.

NSF recognizes this difficulty by assisting manufacturers with formulation disclosures in many ways. First, the agency has a database of over 20,000 material formulations on file. This library can be tapped into by any manufacturer using these materials, saving much effort in obtaining these formulation disclosures. NSF also has staff whose entire function is to contact suppliers and formulators to assist manufacturers in chasing down the required formulation disclosures. Staff are assisted by NSF’s international offices in Europe, Asia and South America to provide local language and contact expertise. Nonetheless, the brunt of the gathering effort is borne by the end product manufacturer seeking certification.

The future of formulation disclosure requirements
Product manufacturers face frustration in working with material and parts suppliers to gather formulation disclosures. Evidence of this frustration was a proposal from a manufacturer at the May, 2007 NSF Drinking Water Treatment Unit Joint Committee meeting to remove the requirement altogether. The concept was that an extraction test that included every possible analytical scan could address the potential contaminants of concern, regardless of what might be disclosed by material formulators. Discussion amongst the Joint Committee revealed that many of the manufacturers do indeed face challenges in obtaining the formulation information, but the consensus was that proper extraction testing could not be conducted without knowledge of the wetted material formulations. There was also concern that any change in wetted materials would automatically require retesting for material extraction, because there would be no way to compare the currently approved and proposed materials. With these thoughts in mind, the proposal to eliminate the formulation disclosure requirement was dismissed by the Joint Committee as inappropriate.

Perhaps there is some middle ground here. There may be a way to simplify and streamline the requirements for formulation disclosure, while addressing concerns about proper extraction testing and alternate materials. It is through this kind of discussion and ultimate evolution that the NSF/ANSI DWTU Standards maintain their credibility and conservatism, yet remain workable in an ever-changing global economy.

About the author
Rick Andrew is the Operations Manager of the NSF Drinking Water Treatment Units Program. Prior to joining NSF, his previous experience was in the area of analytical and environmental chemistry consulting. Andrew has a bachelor’s degree in chemistry and an MBA from the University of Michigan. He can be reached at 1-800-NSF-MARK or email: [email protected].



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