Question 47Safety & Environmental - 1st Asst/Chief

The correct answer is B) there is no possible ethylene oxide concentration in air which is too rich to burn. The reason this is correct is that the explosive limits of a flammable gas, like ethylene oxide, define the range of concentrations in air where the gas can ignite and burn. With an lower explosive limit (LEL) of 2.0% and an upper explosive limit (UEL) of 100% by volume, this means that any concentration of ethylene oxide in air between 2.0% and 100% is within the flammable range and can potentially ignite and burn. There is no concentration that would be considered too rich (too high) to burn. The other answer options are incorrect because: A) is incorrect since there are concentrations below 2.0% that are too lean to burn. C) is incorrect since an ethylene oxide spill does not automatically result in an explosion. D) is incorrect since a 2.0% reading on a combustible gas indicator does not necessarily mean the concentration is exactly 2.0%.