NSF International is an American product testing, inspection and certification agency based in Ann Arbor, Michigan.

NSF / ANSI-61 is an international standard created for the control of products used in systems containing drinking water. The certification process is completed as a result of tests carried out at different pH levels and different water temperatures. Tisan has completed the NSF / ANSI-61 certification process for black PA6 grades with 20% to 60% glass fiber reinforced, UV and heat stabilized in cold water (23C) environment.

http://info.nsf.org/Certified/PwsComponents/Listings.asp?Company=C0507756&Standard=061