The fluoropolymer ECTFE is a durable copolymer of ethylene and chlorofluoroethylene with excellent  resistance to a wide variety of strong acids, solvents, chlorine, and caustics. It has high-performance properties similar to other fluoroplastics like PTFE (Teflon) with some enhancements and at a higher cost. ECTFE offers high tensile strength, excellent impact and abrasion resistance and ultra-low permeability.  Its permeation resistance to oxygen, carbon dioxide, chlorine gas and hydrochloric acid is 10 to 100 times better than PTFE.

ECTFE offers chemical and corrosion resistance over a wide temperature range from cryogenic (-105°F) to over 300°F (-76°C to +150°C). It also has high resistivity and low dielectric constant and is radiation resistant.  Due to the fact that Halar is very pure, it is used in the semiconductor and other industries for ultrapure water and for high purity hydrogen peroxide. ECTFE is joined by thermal butt fusion.
In addition to chemical fluid handling applications, ECTFE is used to minimize wear in high-friction applications where dimensional stability is a requirement.  It is used as a bearing surface for machine tools, cams and valve seats and for semiconductor tooling.  It is also used for wire and cable ways and in electrical insulators due to its high resistivity and low dielectric constant.