Flammable Liquids Flammable liquids can cause a fire or explosion, and like many other substances, they can also cause serious health effects from overexposure. Note: On the NFPA diamond label, a fire hazard rating of 3 or 4 denotes a flammable liquid. 3
Flammable Liquids A flammable liquid is any liquid having a flashpoint below 100°F. –Exception: Any mixture having components with flashpoints of 100°F or higher, the total of which make up 99% or more of the total volume of the mixture. Note: The flash point is the lowest temperature at which a liquid gives off enough vapor to form a flammable mixture with air.
Flammable Liquids The vapors of flammable liquids often present the most serious hazard. –The vapors can easily ignite or explode. –Flammable liquid vapors are heavier than air and may settle in low spots, or move a significant distance from the liquid itself.
Explosive Limits The explosive concentration of vapors in air has a lower and upper limit. –The Lower Explosive Limit (LEL) is the lowest concentration that will ignite. –The Upper Explosive Limit (UEL) is the highest concentration that will ignite. –If the vapor concentration is between the LEL and UEL, there is serious risk of fire or explosion.
Explosive Limits Above the Upper Explosive Limit, the mixture is too rich to burn UPPER EXPLOSIVE LIMIT Explosive Range Below the Lower Explosive Limit, the mixture is too lean to burn LOWER EXPLOSIVE LIMIT
Classification Flammable and combustible liquids are classified according to their flashpoints. This is important to know because the quantity of flammable/combustible liquids that can be stored in any one location is determined by the class of the liquid.
Flammable Liquids Class 1ALiquids having flashpoints below 73°F and having a boiling point below 100°F. Class 1BLiquids having flashpoints below 73°F and having a boiling point at or above 100°F. Class 1CLiquids have flashpoints at or above 73°F and below 100°F.
Combustible Liquids A combustible liquid is any liquid having a flashpoint at or above 100°F. Note: Check your Material Safety Data Sheet (MSDS) sheet for the characteristics or classification of a particular liquid.
Combustible Liquids Class IILiquids with flashpoints at or above 100°F and below 140°F. Class IIILiquids with flashpoints at or above 140°F Class IIIAThose with flashpoints at or above 140°F and below 200°F. Class IIIBThose with flashpoints at or above 200°F.
Area Exempt Amounts There are certain amounts of flammable and combustible liquids stored in each control area that are considered exempt. –If these amounts are exceeded, then the area or building may have to be reclassified as a Hazardous Use Group under the building code.
Excessive storage is a serious violation of the fire code! Contact the EHSS Fire Safety Engineer at for assistance, if necessary.
Storage Areas Flammables should be stored in an approved cabinet in a cool, well ventilated area to avoid pressure buildup and vaporization.
Storage Areas There should be at least one fire extinguisher in the area. –Large storage areas should have a fire protection system installed and must be approved for this use.
Storage Cabinets Use flammable liquid storage cabinets where greater quantities of liquids are needed. Contrary to popular belief, these cabinets are not designed to contain a fire, but to prevent an outside fire from reaching the contents for a period of 10 minutes – enough time to evacuate the area.
Flammable Liquid Exempt Amounts (in gallons) ConditionIAIBIC Inside; unprotected by sprinklers or cabinets Within approved cabinet; unsprinklered structure Not in approved cabinet; sprinklered structure In approved cabinet; sprinklered structure Outside storage
Combustible Liquid Exempt Amounts (in gallons) ConditionIIIIIAIIIB Inside; unprotected by sprinklers or cabinets ,200 Within approved cabinet; unsprinklered structure ,400 Not in approved cabinet; sprinklered structure unlimited In approved cabinet; sprinklered structure. 4801,320 unlimited Outside storage unlimited
Limitations on Storage The maximum storage of flammables and combustibles in any one area under the Virginia Fire Prevention Code is 60 gallons of flammables and 120 gallons of combustibles. These quantities must be in an approved storage area, i.e. a flammables cabinet or other acceptable means.
There are also limitations on quantities stored in individual containers.
Storage Containers Containers should be tightly sealed when not in use. Approved safety cans are recommended for smaller quantities. –The spring-loaded safety cap prevents spillage, prevents vapors from escaping, acts as a pressure vent if engulfed in fire, prevents explosions and rocketing of the can!
Flammable Liquid Limitations (in gallons) ContainerIAIBIC Glass or approved plastic 1 pt.1 qt.1 Metal (other than DOT drum) 155 Safety cans 255 Metal drums (DOT specifications) 60 Approved portable tanks 660
Combustible Liquid Limitations (in gallons) ContainerIIIII Glass or approved plastic11 Metal (other than DOT drums)55 Safety Cans55 Metal drums (DOT specifications)60 Approved portable tanks660
Precautions The unsafe use, storage, dispensing, or disposal of flammable materials can be a prime source of fires and explosions. –Read labels of all spray cans to identify those with flammable gas-propellants. Ex. Butane and Propane
Precautions Some flammable liquids have a tendency to accumulate a static electric charge, which can release a spark that ignites the liquid. –Always bond metal dispensing and receiving containers together before pouring.
Precautions To bond containers, each container is wired together and one container is connected to a good ground point to allow any charge to drain away safely. –Because there is no easy way to bond plastic containers, their use should be limited to smaller sizes (no more than 4L).
Precautions Overexposure to flammable liquids may present health hazards. Consult the Material Safety Data Sheet (MSDS) on the material you will be using to identify health hazards and protective measures to be taken.
Precautions Effects of overexposure to flammable liquids includes: –Inhalation: Irritation to respiratory passages, nausea, headaches, muscle weakness, drowsiness, loss of coordination, disorientation, confusion, unconsciousness, and death.
Preventive Measures Quantities of flammable and combustible liquids located outside of storage cabinets should be restricted to one days supply, or to what can be used during a single shift. –If possible, substitute nonflammable, non- hazardous materials for flammable liquids.
Preventive Measures To prevent the accumulation of vapors inside of storage areas, a continuous mechanical ventilation system must be in place.
Preventive Measures All nonessential ignition sources must be eliminated where flammable liquids are used or stored. –Common ignition sources include: Open flames from cutting and welding Furnaces, matches, heaters, smoking materials Static electricity, friction sparks Motors, switches, circuit breakers
Preventive Measures Materials that contribute to a flammable liquid fire should not be stored with flammable liquids. For example, –Oxidizers –Organic peroxides
Preventive Measures If a spill occurs: –Limit spread by diking with suitable absorbent material. –Minimize vapors by covering surface of spill with same absorbent material. –Ensure all sources of ignition are off or controlled. –Notify your supervisor immediately and call 911 if necessary.
Preventive Measures If a spill occurs: –Begin cleanup right away. Sweep saturated absorbent material into a dustpan. Place material into a metal container with a tight fitting lid. Place any saturated rags or cloths into the same container. Contact EHSS at for pickup and proper disposal.
Preventive Measures Always check the labels of containers (or the MSDS) for recommended personal protective equipment to be worn. –Lab coats –Splash aprons –Eyewear –Gloves –Overboots
Summary Careless mistakes and safety shortcuts lead to serious problems when it comes to flammable liquids. Respect flammable liquids and their dangers - their hazards are deadly…
Contact Information Environmental, Health and Safety Services –www.ehss.vt.eduwww.ehss.vt.edu – Fire Safety –