Slow-drying, soft-setting, non-hardening industrial grade thread sealing compound with added PTFE. Lead-Free, non-toxic. Works for a variety of plumbing, heating and other pipe & fitting applications. NSF certified, CSA approved. Not for use on oxygen systems. RectorSeal 76001 Blue Monster Pipe thread sealant is a non-setting, multi-purpose compound which contains PTFE, plus synthetic fibers to create a stronger seal. Recommended for use on threaded galvanized steel, iron, brass, copper, aluminum, stainless steel, polyethylene, fiberglass reinforced, PVC, CPVC, and ABS pipe. 76001 Blue Monster Pipe may be pressurized immediately following application.