Ethylene Oxide. Ethylene oxide (EtO) is produced in large volumes and is primarily used as an intermediate in the production of several industrial chemicals, the most notable of which is ethylene glycol.It is also used as a fumigant in certain agricultural products and as a sterilant for medical equipment and supplies.thylene Oxide. Ethylene oxide (EtO) is produced in large volumes and is primarily used as an intermediate in the production of several industrial chemicals, the most notable of which is ethylene glycol.