Researchers at Purdue University have...
In August 2006, the editorial staff of Water Quality Products traveled to beautiful Ann Arbor, Mich., to visit NSF International’s state-of-the-art laboratories and offices. In its impressive 146,000-sq ft facility, NSF maintains extensive laboratories supporting product testing services. The purpose of the visit was for the WQP staff to witness firsthand the ins and outs of laboratory operation and product certification.
NSF’s laboratories consist of three major functional areas: chemical, microbiological and physical performance testing. The staff of each functional area has a high level of specialized training and knowledge. The functional areas work closely with other NSF technical departments to establish the testing requirements and conduct the testing used to determine the safety and health effects of NSF-certified products.
These facilities are also used for the homeland security work under the Environmental Technology Verification (ETV) testing of point-of-use (POU) and point-of-entry (POE) drinking water treatment products.
After an introduction of NSF’s mission and benefits, the WQP staff toured the organization’s three major functional areas, which are described below.
One of the first labs WQP staff visited was the Drinking Water Treatment Systems (DWTS) Laboratory. This is the principle laboratory used to test POU and POE water treatment products. The lab features an array of test rigs that simulate typical intermittent residential use of POU products at relatively low (< 5 gpm) flow rates, and typical use of POE, on-demand, at flow rates up to 30 gpm. Some of these test rigs operate in batch mode, with pre-mixed tanks of chemical or microbiological challenge solutions being prepared and analyzed for conformance prior to use. Others operate on the injection principle, with a large recirculating manifold that provides a variety of base test waters to multiple test stands, and concentrated challenge solutions being injected online at each test stand.
The DWTS staff operates tests and collects samples of challenge influents and effluents of POU and POE products for the NSF Chemistry and Microbiology laboratories to analyze. NSF’s DWTS Laboratory generates about 400 analytical samples per week to support POU and POE product testing. The lab is able to perform more than 400 different tests on POU and POE products covering 25 standards from 39 countries over five continents.
After an exciting introduction to the day-to-day operation of the DWTS Laboratory, WQP staff headed to the NSF Chemistry Laboratory. This lab specializes in the determination of trace levels of chemicals in potable water, wastewater and dietary supplements. NSF’s Chemistry Laboratory can detect contaminants at concentrations near 1 ppb. That’s like finding 1 second out of almost 32 years!
The lab staff uses an extensive collection of analytical instruments along with a wide variety of small support equipment necessary for sample preparation and analysis. More than 70 highly skilled professional chemists and other scientists are organized into four groups: Exposure, Organic, Inorganic and Extraction/Gas Chromatography - Mass Spectrometry (GCMS).
The Exposure group designs and develops laboratory exposures to simulate the actual field use of treatment chemicals and other products that come in direct contact with drinking water. The Organic, Inorganic and GCMS groups examine the water from these exposures to determine if any contaminants have migrated from the products into the water. Analyses are performed according to U.S. EPA, Standard Methods, American Society for Testing and Materials (ASTM), AOAC International and FDA protocols, and range from simple tests such as pH, color, taste and odor, to trace level determinations of metals and organic chemicals. For example, in 2005, NSF’s volatile organic contaminant lab analyzed on average more than 175 samples per month to support POU and POE system testing by the DWTS Laboratory. In the same year, the NSF gas chromatography lab analyzed approximately 80 samples per month to support the DWTS Laboratory.
The next stop on the WQP tour of NSF’s facilities was the Microbiology Laboratory. This lab serves as the technical support group for the microbiological testing requirements of NSF programs and projects. These programs include Drinking Water and Bottled Water and related programs; Drinking Water Additives; Food Equipment; Disinfectant and Sanitizers; Biohazard Cabinetry; Pools, Spas and Hot Tubs; and Drinking Water Treatment Units.
The Microbiology Laboratory utilizes official or standardized methodology whenever possible. Sources for analytical methods include regulatory agencies such as the U.S. EPA and FDA, as well as professional and standard-setting organizations like the ASTM and AOAC International. Specialized methods are developed for testing product performance to the criteria established by NSF standards. These methods are reviewed periodically for accuracy and suitability during the standard review process.
The lab is currently classified Biosafety Level II, but in the future will have Level III capabilities for some waterborne microorganisms.
The Microbiology Laboratory personnel have experience in water microbiology (isolation of indicator bacteria, Legionella, E. coli and Giardia), isolation of pathogenic bacteria from foods, and the efficacy of disinfectants and sanitizers. Personnel have been trained in virus propagation and tissue culture, and methods for testing for Cryptosporidium. The laboratory also can perform analysis and identification of Clostridium, enteroviruses, Shigella, Vibrio cholerae and Salmonella.
After a full day of information-packed activities at NSF, the WQP staff returned home with a better knowledge of the multiple levels of the organization. Overall, the staff gained a better understanding and appreciation of NSF’s role in protecting public health through thorough component and product testing and certification.
The staff of WQP would like to extend its gratitude to NSF for its warm reception and helpful educational tour of the facilities. WQP looks forward to another tour after the current facility expansion is complete.
Special thanks to NSF’s Rick Andrew and Kim Van Kirk for providing detailed technical information for this article.