NSF/ANSI Standard 61
A standard related to products that come in contact with drinking water. Developed by NSF and conforming to the ANSI voluntary standard, the standard was accepted by the NSF board in 1988 to confirm that such products will not contribute excessive levels of contaminants into drinking water. Most U.S. states and many Canadian provinces require products used in municipal water distribution systems and building plumbing systems to comply with Standard 61.