Our Yellow Teflon Tape For Gas is a heavy-duty, full-density tape that permits quick, clean and economical sealing of threaded pipe connections. Its full density makes it ideal for gas lines and specifically used on natural gas,propane and butane lines. The tape is made of 99.5% virgin PTFE (a pigment is added for coloring) PTFE, with only a pigment additive for coloring. Its yellow color helps to distinguish it from lower density, general purpose thread sealant tapes.