Glossary
Univocal vapor cloud explosion overpressure assessment

LEL (lower explosive limit)

The LEL of a mixture, also known as the LFL for lower flammable limit, is the smallest proportion of fuel (usually given as a percentage by volume) in an oxidizer-fuel mixture that allows the flame to spread.

UEL (upper explosive limit)

The UEL of a mixture, also known as the UFL for upper flammable limit, is the highest proportion of fuel (usually given as a percentage by volume) in an oxidizer-fuel mixture that allows the flame to spread.

Flammability range

The flammability range is the interval bounded by the LEL and the UEL.

Stoichiometric concentration

Concentration of fuel in the oxidizer-fuel mixture within the flammability range allowing complete combustion without excess or deficient...