|The two primary hazards associated with flammable and combustible liquids are explosion and fire.|
|Safe handling and storage of flammable liquids requires the use of approved equipment and practices per OSHA standards.|
|The determining factor in whether a liquid is flammable or combustible is its flashpoint.
Flashpoint: The minimum temperature at which a liquid gives off enough vapor within a test vessel in sufficient concentration to form an ignitable mixture with air near the surface of the liquid.
Remember, it is the vapors, not the liquid, that Burns!
A chemical’s flashpoint is listed on the MSDS under the Fire and Explosion section.
|Flammable Liquid Classifications|
Any liquid having a flashpoint below 100 deg. F (37.8 deg. C) or higher, the total of which make up 99 percent or more of the total volume of the mixture. Flammable liquids shall be known as Class I liquids. Class I liquids are divided into three classes as follows:
|Combustible Liquid Classifications
Any liquid having a flashpoint at or above 100 deg. F (37.8 deg. C). Combustible liquids shall be divided into two classes as follows:
Class III liquids are subdivided into two subclasses:
|Some Flammable Liquids in the Plant:|
Reference: "The Firefighter's Handbook of Hazardous Materials", 6th Edition, Charles J. Baker.
Explosive limits involve the concentration level of the given chemical in the air.
In popular jargon, a vapor/air mixture below the flammable limit is too lean to burn or explode. A mixture above the upper flammable limits is too rich to burn.
Most flammable liquids are volatile, meaning they evaporate quickly, and can reach a concentration in the air that could lead to an explosion.
|Lower and Upper Explosive Levels (LEL/UEL)
|A good plan for safe use of flammable and combustible liquids contains at least these components:
|Some sources of ignition for flammable and combustible liquids:
|Static Electricty |
|Storage of Flammable and Combustible Liquids|
|Safety Cans for Storage and Transfer |
|Flame Arrester Screen |
|Transferring Flammable Liquids|
Since there is a sizeable risk whenever flammable liquids are handled, OSHA allows only four methods for transferring these materials:
|Self-Closing Safety Faucet |
|Safety Pump |
|Waste and Residue|
Combustible waste and residue must be kept to a minimum, stored in covered metal receptacles and disposed of daily.
|Safe Handling Fundamentals|