Multipurpose Thread Sealant w/ PTFE A non-hardening, non-toxic sealant for sealing and protecting NPT pipe fittings. TFW is specially formulated to seal piping for applications with pressurized air, natural gas, water lines, and fire sprinkler systems, as well as other fluid/air conditions. Benefits of using TFW™ No lead Safe for potable water lines Contains PTFE Non-toxic Non-staining Non-hardening Seals & protects Specifications: Base Materials: Synthetic Certifications: Uniform Plumbing Code (IAPMO) File No. 1282, Federal Spec. TT-S-1732, British Std. 6920, Parts 1 & 2, Nato S-716 Service Rating: 0°F to 500°F, -18°C to 260°C TDS SDS