Ethylene oxide (properly called oxirane, also called epoxyethane, dimethylene oxide, oxacyclopropane, 1,2-Epoxy ethane) is a colorless gas (boiling point 10,7°C) with an ether-like odour. It forms flammable mixtures with air in the range 3...100% EtO. It is a slow poison with carcinogenic, mutagenic, irritating, and anaesthetic effect.

Ethylene oxide is one of the most important raw materials used in large-scale chemical production. It is also used as a sterilant for medical instruments and devices.

Ethylene oxide density is 1,52 of air density.

Lower explosive limit (LEL) = 3 %vol

Flashpoint is -20°C

Ca TWA <0.1 ppm (0.18 mg/m3) C 5 ppm (9 mg/m3) [10-min/day] (NIOSH)