Epichlorohydrin (ECO)

Epichlorohydrin rubber presents as a light amber to tan elastomer with excellent oil resistance and flexibility over a wide temperature range. Key features include exceptional resistance to hydrocarbon fuels and oils, excellent ozone and weather resistance, outstanding low-temperature flexibility, and good heat resistance. It is widely used in automotive fuel systems, oil-field applications, gaskets, seals, and hoses operating in extreme environments. 

Alternatives include acrylic rubber and fluoroelastomers. The industry is trending toward developing grades with improved compression set resistance and processing characteristics. Various subtypes exist including homopolymer (ECO), copolymer with ethylene oxide (CO), and terpolymer versions (GECO) containing epichlorohydrin, ethylene oxide, and a third monomer providing enhanced property profiles, each offering different balances of oil resistance, low-temperature flexibility, and processability.