A review on the experimental studies of the reactivity of ethylene oxide (EO) with various contaminants including water, different kinds of iron oxides and alkalis are presented. It is shown that: (1) Pure EO is not prone to initiate a runaway reaction under 200 degrees C under adiabatic conditions. (2) The possibility of EO aqueous solution to experience an exothermic reaction depends strongly on the EO concentration, and the onset temperatures could be predicted well by a fourth order reaction rate model. (3) EO exhibits different sensitivities to various kinds of iron oxides. Although gamma-Fe2O3 is the most active iron oxide to EO, its runaway reaction consequence is less severe. The reactivity for EO with iron oxides could be: gamma-Fe2O3 > alpha-Fe3O4 > hydrated alpha-Fe2O3 > alpha-Fe2O3. (4) Alkalis could reduce the initial reaction temperature of EO to room temperature with sufficient concentrations, and the proposed hazard potentiality for alkalis is NH4OH > KOH > NaOH. (C) 2017 Elsevier B.V. All rights reserved.