SAF-T-LOK FD-TPS is a non-hardening thread sealant, containing PTFE. SAF-T-LOK FD-TPS does not contain lead or harmful metals. This product is NSF certified for use on potable water lines. It is recommended for heavy duty sealing on joints and pipes. This paste will not run, drip, or separate and is self-lubricating in assembly. The product can be applied as low as 10F; it is non-staining and withstands pressures to 10,000 psi. SAF-T-LOK FD-TPS is NSF/ANSI STANDARD 61 approved for Drinking Water System Components and is used where resistance to chemicals is needed. FD-TPS is also NSF H1Registered. It can be used on services that contain gasoline, kerosene, LP gases, oil, refrigerants/solvents, caustics, many acids, water, gas and steam. It can be used on pipes and threaded connection of all materials: CPCV, PVC, iron, stainless steel, aluminum, brass, plastic, etc.