From water treatment to the tap in homes, products that contact drinking water can impact the quality of what we drink. Consumers and regulatory officials are increasingly more concerned about the effects of lead and other contaminants in drinking water.
Every company that manufacturers devices, components or materials being sold into the United States or Canada, has to be aware that the products will need to be evaluated for health effects to meet regulatory requirements.
Household products and components that could need to meet these requirements are:
- Faucets
- Pipes and Fittings
- Water Heaters and Heat Exchangers
- Ice Makers
- Pumps
- Water Filtration
Manufacturers exporting products to North America may know that NSF/ANSI drinking water standards evaluate health effects from a product, but many are not aware of the the toxicological requirements. Having insight into these requirements not only helps explain why detailed product information is needed and why some projects take longer than others, but also can help manufacturers design products that are more likely to comply.
Some of the standards that establish toxicology requirements by evaluating what leaches out of products into drinking water include:
NSF/ANSI/CAN 61: Drinking Water System Components – Health Effects establishes health effects requirements for products that come into contact with drinking water.
NSF/ANSI/CAN 60: Drinking Water Treatment Chemicals – Health Effects establishes health effects requirements for direct and indirect water treatment chemicals.
NSF/ANSI 42, 44, 53, 55 58, 401 establish not only health effects requirements but also performance, structural, and literature requirements for drinking water treatment units.
When certifying a product to these standards, a manufacturer should know the answer to key questions up front:
When and what information is required on my product?
How is a test battery established?
Where do the pass/fail levels for product extractants come from?
What happens if a clearance level does not already exist?
Yet, many manufacturers are surprised by how much information is required at the start, what happens when a clearance does not exist, and the reasons that lead to longer certification times.
Information Gathering During Pre-evaluation Toxicology
Pre-evaluation toxicology begins by gathering information including
- A list of parts in contact with water or product formulation
- Temperature rating
- Surface area or size range of the product
Volume of water the product is anticipated to hold/come into contact with
Depending on the type of product, a wetted parts list, a formula or both may be required.   A wetted parts list is required for products that have more than one water contact material such as a pump, faucet, valve, or coupling. A formula is required for materials with a single water contact material such as water treatment chemicals, coatings, joining and sealing materials, or process media.
Depending on the product type, end use and the components within the wetted parts list, the information can be reviewed to determine if a full formulation review can be waived.
Designing the product with materials exempt from full formulation review requirements or components/ingredients already certified can often help speed up the certification process.
Formulation Review
With the pre-evaluation toxicology information obtained, a formulation review is done. A formulation review is required for any material that is not exempt from the full formulation information. Certain chemicals are excluded if recognized in a list in the NSF/ANSI/CAN 60 standard. As part of their review, the toxicologist evaluates each ingredient from each formulation taking into consideration the following:
- Known or suspected toxicity of the substance or its byproduct(s);
- High water solubility of the substance;
- Monomer(s) and polymeric ingredients;
- Solvents and cosolvents used in the polymerization process or those used in material formulation;
- Antioxidants, antimicrobials, curing agents, initiators, peroxides, pigments, plasticizers, process aids, stabilizers, and terminators and their impurities, degradation and hydrolysis products;
- High probability of extraction of a substance or its byproduct(s) at toxicologically significant concentrations; and
- Extraction or migration of information for the substance provided by the manufacturer or presented in public literature.
The toxicologist then combines the formulation-dependent analytes from their review with the material-specific analytes identified in the standard to create an analytical summary of all test requirements for that material.
Post-Evaluation Toxicology
Once the test battery is identified, the product is tested according to the requirements in the relevant NSF/ANSI standard. As part of testing, the product is either filled with or dropped into a special test water over a sequence of time defined by the applicable standard. The resulting test water is analyzed for the analytes of interest identified according to the process above and data is received showing which compounds were extracted from the product. The data is adjusted (normalized) to be representative of the product end use. The normalized concentrations are then compared to the pass/fail criteria that is defined in NSF/ANSI/CAN 600. NSF/ANSI/CAN 600, Health Effects Evaluation and Criteria for Chemicals in Drinking Water is the standard that defines the toxicological review process and evaluation procedures and contains all of the currently acceptable pass/fail concentrations of chemicals that are found in the samples being evaluated.
If a compound is present in the evaluation water, it needs to be compared to a pass/fail criteria (clearance) to determine its conformance. Once all contaminants are determined to meet the pass/fail criteria, the product is eligible for certification.
Pass/fail criteria clearances can be categorized into three phases:
- Existing clearances are found in NSF/ANSI/CAN 600;
- Clearances in progress that have been written but not published into NSF/ANSI/CAN 600 yet, e.g., currently going through Joint Peer Review Steering Committee (JPRSC) or the Health Advisory Board (HAB) review or pending publication; and
- New clearances where determination if a new clearance is available depends on the data available for compound or surrogate, or similar compounds.
From Where Does a Contaminant’s Pass/Fail Criteria Originate?
A risk assessment establishes a pass/fail criteria for a contaminant and can vary in effort depending on the information needed and the level of clearance needed. Risk assessments can be qualitative, quantitative, threshold evaluations or class-based clearances.
Depending on the type of risk assessment performed for the clearance, different levels of peer review from external bodies, like the Health Advisory Board, may be required.
If any edits are to be made or the risk assessment is to be returned to the Health Advisory Board for additional review, additional time and monetary costs may accrue until the risk assessment is either accepted or no longer pursued. For compounds not previously identified, a toxicologist will determine the viability of a risk assessment and reports on the findings.
Due to the effort of this process, it is easy to see how a product extracting just one compound without a clearance can add time and money to a project. Designing a product using components or ingredients that already comply with the NSF/ANSI standards can help avoid some of these issues.
Understanding the toxicology requirements early in the product certification process can greatly speed your time to market. Toxicology dictates what information is required up-front to determine a test battery. It is necessary for generating new clearances and determining if contaminants that show up during extraction testing meet requirements. An extensive process exists to obtain a new clearance level that can be time- and cost-intensive. Working with an experienced leader in testing and certification who has a full and deep understanding of the process is critical to the company’s success.
