Ethylene Tetrafluoroethylene (E-CTFE) is commonly known by its trade name HALAR. E-CTFE is essential a 1:1 alternating copolymer of ethylene and CTFE (chlorotrifluoropethylene). It contains about 80% CTFE, one of the most chemically resistant building blocks that can be used to make a polymer. It is most likely the best material for handling high concentrations of sodium hypochlorite. Additionally, E-CTFE has good electrical properties and a broad-use temperature range from cryogenic to 300º F (150º C).