3M Polyimide Film Tape 5413 with DuPont Kapton polyimide film and silicone adhesive used for PCB solder masking and other high temperature applications."Halogen Free" refers to the International Electrochemical Commission’s Definition, IEC 61249-2-21, which sets the limits of: 900 ppm maximum chlorine; 900 ppm maximum bromine; 1500 ppm maximum total halogens