This paper presents new results of an experimental study on the explosion characteristics: the explosion pressure, the rate of pressure rise (or the deflagration index), the explosion delay time and the laminar burning velocity for ethanol/air mixtures with ethanol concentrations between 3.5 vol% and 20.0 vol% in the presence of various diluents (nitrogen, exhaust gas, water and carbon dioxide with dilution concentrations from 0 vol% to 20 vol%), at various initial pressures from 0.25 bar to 1.0 bar and at an initial temperature of 373 K. The influence of the diluent type and amount on the explosion characteristics is examined together with the influence of the initial pressure. The effectiveness of the diluent gases examined varies from least effective to most effective in the following order: N-2, exhaust gas, H2O, CO2. The reported data in this paper (the explosion characteristics and the laminar burning velocity) of ethanol-air mixtures in the presence of various diluents are important safety parameters, useful for design of active protection devices and for safety recommendations. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.