Flamable or Explosive Range of common Gases

Flame and explosion limits of gases

Flame and explosion limits for gases like propane, methane, butane, acetylene, and more.
The Flammable Range (also called Explosive Range) is the concentration range of a gas or vapor that will burn (or explode) if an ignition source is introduced.
Three basic requirements must be met for an explosion to take place:

1. flammable substance – fuel

2. oxidizer – oxygen or air

3. source of ignition – spark or high heat

Below the explosive or flammable range, the mixture is too lean to burn and above the upper explosive or flammable limit, the mixture is too rich to burn. The limits are commonly called the “Lower Explosive or Flammable Limit” (LEL/LFL) and the “Upper Explosive or Flammable Limit” (UEL/UFL).
The lower and upper explosion concentration limits for some commonly used gases are indicated in the table below. Some of the gases are commonly used as fuel in combustion processes.
Note! The limits indicated are for gas and air at 20oC and atmospheric pressure.


Acetaldehyde: 4, 60
Acetic acid4, 19.9
Acetone2.6, 12.8
Acetonitrile3, 16
Acetyl chloride;7.3, 19
Acetylene2.5100Acrolein2.831Acrylic acid2.48Acrylonitrile3.017Allyl chloride2.911.1Allyll alcohol2.518Alyllamine2.222Ammonia1528Aniline1.311Arsine5.178Benzene1.27.8Biphenyl0.65.8Bromobuthane (1-Bromobuthane)2.66.6Bromoethane6.88Bromoethene915Butadiene (1,3-Butadiene)2.012Butanal1.912.5Butane (n-Butane)1.868.41Butanoic acid210Butyl acetate1.77.6Butyl alcohol, Butanol111Butyl formate1.78.2Butyl methyl ketone18Butylamine1.79.8Butylbenzene0.55.8Butylene1.989.65Butyll acrylate1.99.9Carbon disulfide1.350Carbon monoxide1275Carbon oxysulfide1229Chlorobenzene1.39.6Chloroethane3.815.4Cyanogen6.042.6Cyclobutane1.811.1Cycloheptane1.16.7Cyclohexane1.38Cyclohexanol19Cyclohexanone19Cyclopropane2.410.4Decane0.85.4Diacetone alcohol1.86.9Diborane0.888Dibutylamine1.16Dichloroethane (1,1-Dichloroethane)611Diesel fuel0.67.5Diethanolamine213Diethyl ether1.936Diethylamine213Diethylether1.948Diisobutyl ketone16Diisopropyl ether121Dimethyl sulphoxide342Epichlorohydrin421Ethane312.4Ethyl acetate212Ethyl acrylate1.414Ethyl alcohol, Ethanol3.319Ethyl chloride3.815.4Ethyl nitrite450Ethyl propyl ether1.79Ethyl vinyl ether1.728Ethylamine3.514Ethylbenzene1.07.1Ethylcyclobutane1.27.7Ethylene2.7528.6Ethylene oxide3100Etylene glycol322Fluoroethene2.621.7Formaldehyde773Formic acid1857Fuel Oil – No.10.75Furan214Furfural219Gasoline1.47.6Glycerol319Heptane1.06.7Heptane (n-Heptane)1.06.0Hexane1.17.5Hexane (n-Hexane)1.257.0Hydrazine5100Hydrogen475Hydrogen640Hydrogen sulfide4.346Isobutanal1.610.6Isobutane1.808.44Isobutene1.89.0Isobutyl alcohol211Isooctane0.795.94Isopentane1.329.16Isophorone14Isopropyl alcohol, Isopropanol212Isopropylbenzene0.96.5Kerosene Jet A-10.75Mesityl oxide1.47.2Methacrylic acid1.68.8Methane4.416.4Methylamine4.920.7Methyl acetate316Methyl alcohol, Methanol6.736Methyl acrylate2.825Methyl chloride10.717.4Methyl ethyl Ketone1.810Methyl formate4.523Methylhydrazine2.592Methyl isocyanate5.326Mineral spirits0.76.5Naphthalene0.95.9Naphthalene0.95.9Neohexane1.197.58Neopentane1.387.22Nitrobenzene29Nitroethane3.417Nitromethane7.322.2Nonane0.82.9Octane (n-Octane)1.07Oxirane3100Paraformaldehyde773Pentane (n-Pentane)1.47.8Pentene (n-Pentene)1.657.7Pentyl acetat1.17.5Pentylamine2.222Phenol1.88.6Piperidine110Propane2.110.1Propanoic acid2.912.1Propene211.1Propyl acetate28Propylamine210.4Propylbenzene0.86Propyl nitrate2100Propylene2.011.1Propylene oxide2.336Propyne2.112.5Pyridine212Silane1.598Styrene1.16.1Tetrafluoroethene1050Tetrahydrofuran212Toluene1.17.1Trichloroethylene1390Triethylene glycol0.99.2Triptane1.086.69Trimethylamine211.6Turpentine0.8Vinyl acetate2.613.4Vinyl butanoate1.48.8Vinyl chloride3.633o-Xylene0.96.7m-Xylene1.17p-Xylene1.17