Explosive Limits of Common Combustible Gases and Vapors

The range of concentrations of combustible gases and vapours, defined by lower and upper explosive limits expressed as a percentage of the total volume, are those capable of being detonated or ignited by an energy source. The following table gives upper and lower limits of the more common gases determined at atmospheric pressure and where possible room temperature. (The upper limit some vapours were determined at higher temperature because of their low vapour pressures).

The sources of reference are: BS5345 Part 1: 1976 Table 5 ‘Combustion Flame and Explosion of Gases” B. Lewis and CL Von FIbe, Academic Press (1951)