Explosive limits are the proportion of flammable vapors or flammable gases between which the mixture is flammable or explosive.

Explosive limit of ETHYL METHYL KETONE is 1.8% to 11.5%.

Which means in a given volume of air if the volume of vapor of ETHYL METHYL KETONE is between 1.8 to 11.5 it will cause an explosion if there is an ignition source.

Lower and upper limits of flammable range is called Lower Explosive Limit (LEL) and Upper Explosive Limit (UEL)

Lower Explosive Limit is the lowest concentration of gas or vapor which can produce a flash when an ignition source is present.

Upper Explosive Limit is the highest concentration of gas or vapor which can produce a flash when an ignition source is present.

For Ethyl Methyl Ketone which has explosive limits 1.8% to 11.5% If the vapor concentration is below 1.8 the mixture is too lean to cause an explosion and if the concentration is above 11.5 the mixture is too rich to cause and explosion.