These fire safety slides focus on classes of fire, sources of ignition, fire extinguishers, safe storage and handling of flammable/combustible liquids.

1. Flammable & Combustible Liquids
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Bureau of Workers’ Compensation
PA Training for Health & Safety
(PATHS)
OSHA 29 CFR
1910.106

2. Topics
 Important Definitions
 Class of Flammable & Combustible Liquids
 Components of a Good Plan for Safe Use
 Sources of Ignition
 Static Electricity, Grounding, and Bonding
 Safe Storage, Use, and Handling
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3. Introduction
 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.
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4. Flash Point & Flammable Liquids
 Flash point – the minimum temperature at
which a liquid gives off enough vapor to form
an ignitable mixture.
 In general, the lower the flash point, the
greater the hazard.
 Flammable liquids have flash points below
100oF, and are more dangerous than
combustible liquids, since they may be ignited
at room temperature
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5. Combustible Liquids
 Combustible liquids have flash points at or
above 100oF.
 Although combustible liquids have higher flash
points than flammable liquids, they can pose
serious fire and/or explosion hazards when
heated.
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6. Definitions
 Volatility = tendency or ability of a liquid to vaporize.
 Vapor pressure = measure of a liquid’s volatility. A high
vapor pressure usually is an indication of a volatile
liquid, or one that readily vaporizes.
 Boiling point = temperature at which the vapor
pressure equals atmospheric pressure, such that the
pressure of the atmosphere can no longer hold the liquid
in a liquid state and bubbles begin to form. Generally,
low boiling point indicates high vapor pressure (possibly,
increased fire hazard).
 Flashpoint = the least temperature at which vapors are
ignited by an ignition source and go out; no sustained
combustion.
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7. Definitions
 Flammable range = proportion of vapor to air mixture
that is ignitable (expressed in terms of percentage of
vapor in air by volume).
 Ignition Temperature = A temperature unique to
various materials where they will combust due to an
open flame source.
 Auto ignition temperature = minimum temperature at
which a vapor-air mixture will spontaneously ignite,
without the necessity of a spark or flame.
 Vapor density = measure of a vapor’s weight when
compared to air (air assigned value of 1). Denser vapors
tend to sink to floor level, less dense vapors tend to rise
to ceiling level.
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8. Classes
Of Flammable & Combustible Liquids:
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IIIA
II
IC
IA IB
200
140
100
73
Flash
Point
(
o
F)
100
Boiling Point (oF)
Combustible
(FP > 100oF)
Flammable
(FP < 100oF)

9. Classes of Flammable Liquids
 Class IA = flash point below 73 °F; boiling
point below 100 °F.
 Class IB = flash point below 73 °F; boiling
point greater than or equal to 100 °F.
 Class IC = flash point greater than or equal
to 73 °F and below 100 °F.
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10. Classes of Combustible Liquids
 Class II = flash point greater than or equal to
100 °F and below 140 °F.
 Class IIIA = flash point greater than or equal
to 140 °F and below 200 °F.
 Class IIIB = flash point greater than or equal
to 200 °F.
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11. Classes of Some Flammable Liquids
Common Name Flash Point
CLASS IA Ethyl Ether -49
CLASS IB Gasoline -45
Methyl Ethyl Ketone 21
Toluene 40
CLASS IC Xylene 81-115
Turpentine 95
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12. Good Plan Components
A good plan for safe use of flammable and
combustible liquids contains at least these
components:
 Control of ignition sources
 Proper storage
 Fire control
 Safe handling
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13. Sources of Ignition
Take adequate precautions to prevent ignition of
flammable vapors. Some sources of ignition
include:
• Open flames
• Smoking
• Static electricity
• Cutting and welding
• Hot surfaces
• Electrical and mechanical sparks
• Lightning
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14. Static Electricity
• Generated when a fluid flows through a pipe or
from an opening into a tank.
• Main hazards are fire and explosion from
sparks containing enough energy to ignite
flammable vapors.
• Bonding or grounding of flammable liquid
containers is necessary to prevent static
electricity from causing a spark.
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15. Bonding
• Physically connect two
conductive objects together
with a bond wire to
eliminate a difference in
static charge potential
between them.
• Must provide a bond wire
between containers during
flammable liquid filling
operations, unless a
metallic path between
them is otherwise present.
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16. Grounding
• Eliminates a difference in
static charge potential
between conductive objects
and ground.
• Bonding eliminates a
difference in potential
between objects.
• Does not eliminate a
difference in potential
between these objects &
earth.
• Unless one of the objects is
connected to earth with a
ground wire.
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17. Ventilation
Always provide adequate ventilation to
reduce the potential for ignition of
flammable vapors.
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18. Storage Fundamentals
• Identify incompatible chemicals – check the
Safety Data Sheet (SDS).
• Isolate and separate incompatible materials:
o Isolate by storing in another area or room.
o Degree of isolation depends on quantities,
chemical properties and packaging.
o Separate by storing in same area or room,
but apart from each other.
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19. Storage
• Storage must not limit the use of
exits, stairways, or areas
normally used for the safe egress
of people.
• In office occupancies:
o Storage prohibited except that
which is required for
maintenance and operation of
equipment.
o Storage must be in:
 closed metal containers
inside a storage cabinet, or
 safety cans, or
 an inside storage room
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Inside storage room

20. Safety Cans
For Storage and Transfer:
 Approved container of not
more than 5 gallons capacity.
 Spring-closing lid and
spout cover.
 Safely relieves internal
pressure when exposed
to fire.
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21. Flame Arrester Screen
 Prevents fire flashback
into can contents.
 Double wire-mesh
construction.
 Large surface area:
o Provides rapid dissipation
of heat from fire.
o Vapor temp inside can
remains below ignition
point.
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22. Storage Cabinets
 Not more than 60 gal of Class I
and/or Class II liquids, or not
more than 120 gal of Class III
liquids permitted in a cabinet.
 Must be conspicuously labeled,
“Flammable - Keep Fire Away.”
 Doors on metal cabinets must
have a three-point lock (top,
side, and bottom), and the door
sill must be raised at least 2
inches above the bottom of the
cabinet.
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23. Fire Control
• Suitable fire control devices
(e.g. small hose or portable
fire extinguishers) must be
available where flammable or
combustible liquids are stored.
• Open flames and smoking are
not permitted in these areas.
• Materials that react with water
must not be stored in the
same room with flammable or
combustible liquids.
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24. Which Can I Use?
For Flammable/Combustible Liquids Fires?
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Water
- No
Dry
Chemical
(BC) - Yes
Multi-Purpose
(ABC) - Yes
CO2 -
Yes

25. Transferring Flammable Liquids
Sizeable risk whenever flammable liquids are
handled, OSHA allows only four methods for
transferring:
Through a closed piping system.
From safety cans.
By gravity through an approved self-closing
safety faucet.
By means of a safety pump.
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26. Self-Closing Safety Faucet
• Bonding wire between drum
and container.
• Grounding wire between
drum and ground.
• Safety vent in drum
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27. Safety Pump
 Faster and safer than using
a faucet.
 Spills less likely.
 No separate safety vents in
drum required.
 Installed directly in drum
bung opening.
 Some pump hoses have
integral bonding wires.
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28. Waste and Residue
Combustible waste and residue must be kept to
a minimum, stored in covered metal receptacles,
and disposed of daily.
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Waste drum with
disposal funnel
Safety disposal can Oily-waste can
(self-closing lid)

29. Safe Handling Fundamentals
For Flammable Liquids:
 Carefully read the manufacturer’s label on the
container before using or storing it.
 Practice good housekeeping in flammable liquid
storage areas.
 Clean up spills immediately, then place the
rags used in a covered metal container.
 Only use approved metal safety containers or
original manufacturer’s container to store
flammable liquids
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30. Safe Handling Fundamentals
For Flammable Liquids:
 Keep the containers closed when not in use and
store away from exits or passageways.
 Use flammable liquids only where there is
plenty of ventilation.
 Keep flammable liquids away from ignition
sources such as open flames, sparks, smoking,
cutting, welding, etc.
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31. Summary
 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.
 An excellent reference on this topic is National
Fire Protection Association Standard No. 30,
Flammable and Combustible Liquids Code.
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32. Contact Information
Health & Safety Training Specialists
1171 South Cameron Street, Room 324
Harrisburg, PA 17104-2501
(717) 772-1635
RA-LI-BWC-PATHS@pa.gov
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33. Questions
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