â¢Certification to NSF-61 provides assurance to a highest level that this material is safe for use in drinking water service..â¢NSF-61 Compressed Fiber Sheet technology provides mechanical and service characteristics unmatched by standard elastomeric gradesâ¢When a gasket is submitted for testing, the formulation is reviewed for prohibited substances, and then tested for contaminants that could leach out of the gasket into your drinking waterâ¢Temperature: Continuous Service: 500ºF (260ºC),Maximum Service: 752ºF (400ºC), Pressure: Continuous Service: 1160 psi (80 bar) Maximum Service: 1595 psi (110 bar)â¢Macho O-Ring & Seal NSF-61 is suitable for service handling the following general media categories: Drinking Water, Diluted alkalis, Industrial gases, General chemicals.