Primarily to make ethylene glycol (a chemical used to make antifreeze and polyester). Used for 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.
Ethylene oxide is a colorless gas at 25 °C and is a mobile liquid at 0 °C – viscosity of liquid ethylene oxide at 0 °C is about 5.5 times lower than that of water. The gas has a characteristic sweet odor of ether, noticeable when its concentration in air exceeds 500 ppm. Heating ethylene oxide to 100 °C with carbon dioxide, in a non-polar solvent in the presence of bis -(triphenylphosphine)-nickel(0) results in ethylene carbonate : In industry, a similar reaction is carried out at high pressure and temperature in the presence of quaternary ammonium or phosphonium salts as a catalyst. Ethylene oxide is a man-made chemical that is used primarily to make ethylene glycol (a chemical used to make antifreeze and polyester). 1 Ethylene oxide rapidly breaks down when released to the environment. 2  Because ethylene oxide is a gas, most is expected to be released to the air where it reacts with water vapor and sunlight and breaks down within a few days. The epoxy cycle of ethylene oxide is an almost regular triangle with bond angles of about 60° and a significant angular strain corresponding to the energy of 105 kJ/mol. For comparison, in alcohols the C–O–H angle is about 110°; in ethers, the C–O–C angle is 120°. Heating ethylene oxide to 100 °C with carbon dioxide, in a non-polar solvent in the presence of bis -(triphenylphosphine)-nickel(0) results in ethylene carbonate : In industry, a similar reaction is carried out at high pressure and temperature in the presence of quaternary ammonium or phosphonium salts as a catalyst. At room temperature, ethylene oxide is a flammable colorless gas with a sweet odor. It is used primarily to produce other chemicals, including antifreeze. In smaller amounts, ethylene oxide is used as a pesticide and a sterilizing agent. The ability of ethylene oxide to damage DNA makes it an effective sterilizing agent but also accounts for its cancer-causing activity.  Burning fuels such as petroleum, natural gas, and coal may release ethylene oxide. Because ethylene oxide has been used in growing tobacco leaves, tobacco smoke is another source of ethylene oxide emissions. Exposure to ethylene oxide occurs primarily in the workplace. You can be exposed to ethylene oxide by inhaling, swallowing, or touching it. Small amounts of ethylene oxide are used in pesticides, insecticides, and fumigants for spices, books, leather, paper, furniture, beekeeping equipment, and transportation vehicles. It is used to sterilize medical equipment and supplies and to purify cocoa, flour, coconut, fruits, dehydrated vegetables, and cosmetics. Ethylene Oxide Gas Sterilization. The gas I'm talking about is called ethylene oxide. This is a type of flammable and explosive gas that is used for the sterilization of medical equipment and devices. The way by which ethylene oxide kills off microbes is through a reaction known as alkylation.  Ethylene oxide is industrially produced by direct oxidation of ethylene in the presence of silver catalyst. It is extremely flammable and explosive and is used as a main component of thermobaric weapons; therefore, it is commonly handled and shipped as a refrigerated liquid. Heating ethylene oxide to 100 °C with carbon dioxide, in a non-polar solvent in the presence of bis -(triphenylphosphine)-nickel(0) results in ethylene carbonate : In industry, a similar reaction is carried out at high pressure and temperature in the presence of quaternary ammonium or phosphonium salts as a catalyst. Ethylene Oxide (EtO) sterilization is mainly used to sterilize medical and pharmaceutical products that cannot support conventional high temperature steam sterilization-such as devices that incorporate electronic components, plastic packaging or plastic containers.  CAS ID #: 75-21-8. Summary: Ethylene oxide is a flammable gas with a somewhat sweet odor. It dissolves easily in water. Ethylene oxide is a man-made chemical that is used primarily to make ethylene glycol (a chemical used to make antifreeze and polyester). 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. 
https://en.wikipedia.org/wiki/Ethylene_oxide http://www.atsdr.cdc.gov/toxfaqs/TF.asp?id=733&tid=133 https://en.wikipedia.org/wiki/Ethylene_oxide http://www.cancer.gov/about-cancer/causes-prevention/risk/substances/ethylene-oxide http://toxtown.nlm.nih.gov/text_version/chemicals.php?id=71 http://study.com/academy/lesson/what-is-ethylene-oxide-uses-safety-technology.html https://en.wikipedia.org/wiki/Ethylene_oxide http://www.eurotherm.com/industries/life-sciences/applications/eto-sterilization/ http://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=133 https://www.osha.gov/SLTC/ethyleneoxide/
what is ethylene oxide used for