1. Flammable and Combustible Liquids
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Flammable and Combustible Liquids
by Environmental, Health and Safety Services

2. Overview Methyl formate Lacquer thinner Gasoline Toluene
Isopropyl alcohol
Definitions
Classes of Liquids
Precautions
Storage Requirements
Preventive Measures
Diethyl ether
Acetone
MEK
Methyl formate
Ethyl ether
Kerosene

3. Flammable Liquids
Flammable liquids can cause a fire or explosion, and like many other substances, they can also cause serious health effects from overexposure.
Examples of flammables:
-acetone
-gasoline
-lacquer thinner 3
Note: On the NFPA diamond label, a fire hazard rating of 3 or 4 denotes a flammable liquid.

4. 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.
FLSP page 43
Note: The flash point is the lowest temperature at which a liquid gives off enough vapor to form a flammable mixture with air.

5. 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.

6. 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.

7. Explosive Limits
Above the Upper Explosive Limit, the mixture is too rich to burn
UPPER EXPLOSIVE LIMIT
Explosive Range
LOWER EXPLOSIVE LIMIT
Below the Lower Explosive Limit, the mixture is too lean to burn

8. 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.

9. Flammable Liquids Class 1A
Liquids having flashpoints below 73°F and having a boiling point below 100°F.
Class 1B
Liquids having flashpoints below 73°F and having a boiling point at or above 100°F.
Class 1C
Liquids have flashpoints at or above 73°F and below 100°F.
FLSP page 43

10. 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.
FLSP page 43
Examples of combustibles:
-kerosene
-fuel oil
-Stoddard solvent

11. Combustible Liquids Class II
Liquids with flashpoints at or above 100°F and below 140°F.
Class III
Liquids with flashpoints at or above 140°F
Class IIIA
Those with flashpoints at or above 140°F and below 200°F.
Class IIIB
Those with flashpoints at or above 200°F.
FLSP page 43

12. 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.
FLSP page 43

13. Excessive storage is a serious violation of the fire code!
Contact the EHSS Fire Safety Engineer at for assistance, if necessary.

14. Storage Areas
Flammables should be stored in an approved cabinet in a cool, well ventilated area to avoid pressure buildup and vaporization.
FLSP page 15

15. 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.
FLSP page 15

16. 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.
FLSP page 15

17. Flammable Liquid Exempt Amounts (in gallons)
Condition IA IB IC
Inside; unprotected by sprinklers or cabinets. 30 60 90
Within approved cabinet; unsprinklered structure.
120
180
Not in approved cabinet; sprinklered structure.
In approved cabinet; sprinklered structure.
240
360
Outside storage.

18. Combustible Liquid Exempt Amounts (in gallons)
Condition II
IIIA
IIIB
Inside; unprotected by sprinklers or cabinets.
120
330
13,200
Within approved cabinet; unsprinklered structure.
240
660
26,400
Not in approved cabinet; sprinklered structure.
unlimited
In approved cabinet; sprinklered structure.
480
1,320
Outside storage.

19. 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.
Va. Fire Prevention Code
These quantities must be in an approved storage area, i.e. a flammables cabinet or other acceptable means.

20. There are also limitations on quantities stored in individual containers.
FLSP page 44

21. 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!
FLSP page 15

22. Flammable Liquid Limitations (in gallons)
Container IA IB IC
Glass or approved plastic
1 pt.
1 qt. 1
Metal (other than DOT drum) 5
Safety cans 2
Metal drums (DOT specifications) 60
Approved portable tanks
660
FLSP page 44

23. Combustible Liquid Limitations (in gallons)
Container II
III
Glass or approved plastic 1
Metal (other than DOT drums) 5
Safety Cans
Metal drums (DOT specifications) 60
Approved portable tanks
660
FLSP page 44

24. 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.
FLSP page 12
Ex. Butane and Propane

25. Precautions gasoline benzene xylene toluene
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.
FLSP page 15
gasoline
benzene
xylene
toluene

26. 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).
FLSP page 15

27. 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.

28. 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.
From Toolbox Topic

29. Precautions
Skin Contact: irritated, dry, cracked skin, rashes, dermatitis.
Eye Contact: burning, irritation, eye damage.
Ingestion: irritated digestive tract, poisoning, death.
From Toolbox Topic

30. Preventive Measures
Quantities of flammable and combustible liquids located outside of storage cabinets should be restricted to one day’s supply, or to what can be used during a single shift.
If possible, substitute nonflammable, non-hazardous materials for flammable liquids.
FLSP page 15

31. Preventive Measures
To prevent the accumulation of vapors inside of storage areas, a continuous mechanical ventilation system must be in place.
FLSP page 16

32. 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
FLSP page 16

33. Preventive Measures
Materials that contribute to a flammable liquid fire should not be stored with flammable liquids. For example,
Oxidizers
Organic peroxides
FLSP page 16

34. 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.
FLSP page 16

35. 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.
FLSP page 16

36. 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

37. 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…

38. Contact Information
Environmental, Health and Safety Services
Fire Safety
Thank you!