Plumber's tape is made from a fluoropolymer PTFE (polytetrafluoroethylene). PTFE is nonflammable and nontoxic. This product goes by various names, including "PTFE tape", or Teflon tape, a brand name for PTFE.
It is also called thread seal tape, plumber tape, pipe wrap tape, or seal tape because its most common application is to seal pipe threads in plumbing or irrigation projects.
To form a proper seal every pipe threaded fitting should be wrapped with thread sealant tape. Wrap 3-4 layers clockwise around the threads then connect the parts.
It works on plastic, brass, copper, aluminum, PVC and iron piping