Explosive Limits
| Formula / Notation | LEL to UEL range (% by volume in air) |
|---|---|
| Also Known As | Flammable limits; explosive range; LEL (lower explosive limit); UEL (upper explosive limit); LFL (lower flammable limit); UFL (upper flammable limit) |
What is Explosive Limits?
Explosive limits (also called flammable limits) define the range of concentrations of a flammable gas or vapour in air that can ignite and sustain a flame. The Lower Explosive Limit (LEL) is the minimum concentration below which the mixture is too lean to ignite. The Upper Explosive Limit (UEL) is the maximum concentration above which the mixture is too rich to ignite. Between LEL and UEL, the mixture is explosive.
Formula & Notation
Other Names / Synonyms: Flammable limits; explosive range; LEL (lower explosive limit); UEL (upper explosive limit); LFL (lower flammable limit); UFL (upper flammable limit)
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
Explosive limits (also called flammable limits) define the range of concentrations of a flammable gas or vapour in air that can ignite and sustain a flame. The Lower Explosive Limit (LEL) is the minimum concentration below which the mixture is too lean to ignite. The Upper Explosive Limit (UEL) is the maximum concentration above which the mixture is too rich to ignite. Between LEL and UEL, the mixture is explosive.
Industrial safety and process design; ventilation system design; gas leak detection (LEL sensors); storage regulations for flammable gases and vapours; fire and explosion risk assessment; transport of dangerous goods; safety engineering
Critical safety parameter — operating within the explosive range with an ignition source causes explosion or fire. Use LEL monitors in areas with flammable gases. Maintain concentrations below 10–25% LEL in workplaces. Eliminate ignition sources in flammable atmospheres.
The formula or notation for Explosive Limits is: LEL to UEL range (% by volume in air)