Explosives ethylene-ozone mixtures

Ethylene forms explosive mixtures in air the LEE and UEL values are 2.7% and 36% by volume of air, respectively. Its reaction with fluorine is explosively violent (AH = —112 kcal/mol), and violent with chlorine (AH = —36 kcal/mol). In the presence of sunlight or UV light, an ethylene-chlorine mixture will explode spontaneously. The reaction is explosive at room temperature over the oxides of mercury or silver (Mellor 1946, Suppl. 1956). Ethylene reacts vigorously with oxidizing substances. It reacts with ozone to form ethylene ozonide, H2C(03)CH2, which is unstable and explodes on mechanical shock. Acid-catalyzed addition of hydrogen peroxide may produce ethyl hydroperoxide, which is unstable and explodes on heat or shock ... 

At atmospheric pressure, when the mixture was admitted through the aluminum tip, no ignition took place with hydrogen, cyanogen, and methane (ozone rate 6 cc. per second). Carbon monoxide and ethylene, however, ignited spontaneously and burned normally afterwards without initiating an explosion or detonation in the ozone line. 

The limits, especially the upper limits, are slightly lower in smaller tubes due to the influence of the tube walls. The upper explosive limit of ethylene and air mixtures is raised from 16 per cent by volume of the hydrocarbon at 0 atmospheres pressure to 71 per cent at about 350 atmospheres pressure.32 It is probable that in the experiments with ozone to be described that the ozone acted as a trigger to set off the reaction which occurs with explosive violence when the proper mixtures of oxygen and ethylene are present.28... 

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