CoatingsPro Magazine

JUL 2013

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Science Behind it WHy Is NsF CertIFICatIoN oF Potable Water CoatINgs ImPortaNt? By Dave Purkiss, NSF N SF International, which was formerly the National Sanitation Foundation and hereafter referred to as "NSF," helps protect you by certifying products and writing standards for food, water, and consumer goods, according to the website at www.nsf.org. One of those standards, NSF/American National Standards Institute (ANSI) Standard 61: Drinking Water System Components – Health Effects, was created at the request of the U.S. Environmental Protection Agency (EPA) in 1984 to ensure that products used in public drinking water systems would not contribute chemical contaminants to drinking water at levels that could cause adverse human health effects. Today, 47 U.S. states, several provinces in Canada, and other cities throughout the world specify NSF/ANSI 61 certification for coatings that are used to line potable water piping systems, storage tanks, and other structures that come in contact with drinking water. What It Is Water utilities in the United States, Canada, South Korea, Saudi Arabia, and the United Arab Emirates (UAE) have required NSF/ANSI 61 certification for water main piping products to prevent the addition of toxic chemicals, which can migrate from products that do not comply with NSF/ ANSI 61. It is known that certain products can contribute harmful levels of chemicals, such as lead, phthalates, butadiene, acrylonitrile, vinyl chloride, styrene, and bisphenol A, to drinking water. Water utility treatment facilities can be confident that, when using products that are certified to NSF/ANSI Standard 61, they have been tested to ensure that the products will not contribute unsafe levels of chemical contaminants to drinking water. NSF/ANSI Standard 61: Drinking Water System Components – Health Effects is a performance-based standard that evaluates the amount of contaminants that leach from the products into drinking water rather than setting prescriptive limits on content. This differs from FDA requirements, volatile organic compound (VOC) content limits, and some international standards that are based on prescriptive content requirements. Prior to the development of NSF/ANSI 61, many U.S. states had various requirements for coatings that are used in drinking water applications. NSF/ANSI 61 has provided a harmonized protocol, which is a great benefit for manufacturers that only need to meet one set of criteria to sell across the country. How It's Done Coating manufacturers pursue certification by submitting a coating formulation to NSF for confidential toxicology review. This is done to identify chemical ingredients, reaction byproducts, and trace contaminants that might leach from coatings into drinking water. NSF conducts an audit of the manufacturing facility to verify the formulation and production process and to verify that only authorized ingredients from authorized suppliers are used. A key requirement to product certification is that the manufacturer has to have a controlled process that ensures that each batch of product made each and every day is identical to the sample that is tested to NSF/ANSI Standard 61. NSF/ANSI Standard 61 requires analysis for any chemicals that leach from a material into drinking water, and it requires a toxicological evaluation of chemical concentrations to ensure that they are below levels that may cause potential adverse human health effects. The toxicological evaluation criteria are based on a lifetime exposure to the concentration of contaminants in drinking water. Once products are certified, the NSF certification process also requires annual, unannounced audits of the product manufacturing facility where product samples are collected and retested each year to ensure that they continue to comply with the requirements of the standard. Items that can have a major impact on the leaching of contaminants from coatings into water include cure time, coating thickness, and number of coats that are applied. For that reason, NSF/ANSI 61 certification requires testing of the product at the manufacturer's recommended maximum coating thickness, maximum number of coats, and the minimum cure time. This information is required to be contained in the manufacturer's use instructions and also printed in the NSF/ANSI 61 certification listing that is available on the NSF website at: http://www.nsf.org/ Certified/PwsComponents/ If the coating is applied outside of these parameters, the certification of the coating is void. Additionally, contractors and specifiers should always check state and other local regulations to see if there are any other requirements besides NSF/ANSI Standard 61 for the coatings they are using. For more information, check out www.nsf.org or contact Dave Purkiss at purkiss@nsf.org or at (734) 827-6855. CP July 2013 g www.coatingspromag.com 67

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