NSF International has developed a test method (NSF Protocol 477: Drinking Water Treatment Units–Microcystin) that verifies a water filter’s ability to reduce microcystin to below health advisory levels set by the US EPA. The first products to earn certification to the protocol are Access Business Group’s eSpring models 100185, 100188 and 100189 and Coway Co., Ltd. models CIFN11-PLUS, CIFN11S-PLUS, CIFN14-PLUS, CIFN8-PLUS and CIFN85-PLUS. Four international plumbing and building codes now require that water reuse systems comply with NSF/ANSI 350: Onsite Residential and Commercial Water Reuse Treatment for water reuse systems. The 2015 International Residential Code (IRC), International Plumbing Code (IPC), Uniform Plumbing Code (UPC) and International Green Construction Code (IgCC) now all require that water reuse systems used for residential toilet and urinal flushing comply with the standard.