The coatings landscape is changing dramatically with more stringent VOC laws and extractables standards for drinking water, the products owners can rely on for lining their storage vessels is shifting. The author will discuss the advantages of using high film build, edge retentive 100% solids epoxy technology for steel potable water storage tanks. The discussion will center around rapid curing and return to service, increased life cycle expectations, reduction in potential taste & odor issues as well as the overall reduction in cost of ownership.
Introduction:
Beginning in January 2023 the extractables standards for NSF 61/600 for three primary solvents, Toluene, Xylene, and Ethylbenzyne will be significantly reduced from their current levels. This dramatic reduction on acceptable extractables in drinking water, while positive for health and safety standards for human consumption, will create challenges for the coatings and linings industry to ensure the barrier materials used in direct contact with drinking water comply with the standards.
Due to the sheer importance of clean water, an agglomeration of standards is dedicated to drinking water systems. These standards have even reached such substantial levels of user importance that two notable standards—NSF/ANSI/CAN 61-2020 and NSF/ANSI/CAN 60-2020—even have a companion standard. This is NSF/ANSI/CAN 600, and it focuses on the “Health Effects Evaluation and Criteria for Chemicals in Drinking Water.” These two drinking water product standards have seen a medley of changes over the years. First commencing development at the request of the U.S. Environmental Protection Agency (EPA) in 1985 and first published in 1988, NSF/ANSI 61 and NSF/ANSI 60, while also being American National Standards, were designated as National Standards of Canada in 2019, hence their current designation NSF/ANSI/CAN. Their 2018 revisions saw the issuing of NSF/ANSI/CAN 600, the content of which had previously existed in the annexes of these two standards. Specifically, Clause 3 of NSF/ANSI/CAN 600, “Toxicology review and evaluation procedures,” existed in past editions of NSF/ANSI 61 and 60 as Annex A, and 4, “Normative drinking water criteria” used to be Annex C in NSF/ANSI 60 and Annex D in NSF/ANSI 61. NSF/ANSI/CAN 600: What’s Covered? In providing support, NSF/ANSI/CAN 600 contains information on the toxicological review and evaluation procedures for substances imparted to drinking water through contact with drinking water system components and additives. In defining these areas, the standard establishes the human health risk, if any, to drinking water under the anticipated use conditions of these products.
