This document outlines Occupational Safety and Health Administration (OSHA) standards for the storage, handling, and use of flammable and combustible liquids. It provides definitions for key terms like flash point, fire point, vapor pressure, and classes of flammable liquids. The standards specify requirements for controlling ignition sources like bonding/grounding containers, ventilation, and prohibiting smoking or open flames. Requirements are provided for storage in approved containers, portable tanks, storage cabinets, and inside storage rooms. The document also addresses fire control measures, maximum storage quantities, liquid transfer methods, handling, and housekeeping practices.

1. Hazardous
Materials
Subpart H

2. Subpart H Standards
• 1910.101 Compressed Gases
• 1910.102 Acetylene
• 1910.103 Hydrogen
• 1910.104 Oxygen
• 1910.105 Nitrous Oxide
• 1910.106 Flammable and Combustible
Liquids

3. Subpart H Standards
• 1910.107 Spray Finishing using
Flammable and Combustible
Materials
• 1910.108 Dip Tanks containing
Flammable and Combustible
Liquids
• 1910.109 Explosives and Blasting Agents

4. Subpart H Standards
• 1910.110 Storage and Handling of
Liquefied Petroleum Gases
• 1910.111 Storage and Handling of
Anhydrous Ammonia
• 1910.119 Process Safety Management of
Highly Hazardous Chemicals
• 1910.120 Hazardous Waste Operations
and Emergency Response

5. Subpart H Standards
• 1910.123 Dipping and coating
operations: Coverage and
Definitions
• 1910.124 General Requirements for
Dipping and Coating
Operations

6. Subpart H Standards
• 1910.125 Additional Requirements for
Dipping and Coating
Operations that use Flammable
or Combustible Liquids
• 1910.126 Additional Requirements for
Special Dipping and Coating
Operations

7. Definitions
• Hazardous Chemical
• Occupational Safety & Health Act (OSHA)
term that denotes any chemical that would be a
risk to employees if exposed in the work place

8. Definition
• Highly Hazardous Chemical
• OSHA term that denotes any chemical that
would posses toxic, reactive, flammable or
explosive properties

9. Flammable and
Combustible Liquids
1910.106

10. Definitions
• Aerosol
• Aerosol shall mean a material which is
dispensed from its container as a mist,
spray, or foam by a propellant under
pressure

11. Definitions
• Approved
• Approved shall mean an approved or listed
by a national recognized testing laboratory
• Such as:
– Underwriters Laboratories (UL) or
– Factory Mutual (FM)

12. Definitions
• Boiling Point
• Boiling point shall mean the boiling point
of a liquid at a pressure of 14.7 pounds per
square inch absolute (psia). The pressure is
equivalent to 760 millimeters of mercury
(760 mm Hg)
• Liquid changes into a vapor

13. Definitions
• Boiling Point
• At temperatures above the boiling, the pressure of
the atmosphere can no longer hold the liquid in the
liquid state and bubbles begin to form.
• The lower the boiling point, the greater the vapor
pressure at normal ambient temperatures and
consequently the greater the risk.

14. Definitions
• Container
• Container shall mean any can, barrel, or drum

15. Definitions
• Closed Container
• Closed container shall mean a container so
sealed by means of a lid or other device that
neither liquid or vapor will escape from it at
ordinary temperatures

16. Definitions
• Fire Area
• Fire area shall mean an area of a building
separated from the remainder of the
building by construction having a fire
resistance of at least 1 hour and having all
communicating openings properly protected
by an assembly having a fire resistance
rating of at least one hour.

17. Definitions
• Flash Point
• Flash point means the minimum
temperature at which a liquid gives off
vapor within a test vessel in sufficient
concentration to form an ignitable mixture
with air near the surface of the liquid. The
flash point is normally an indication of
susceptibility to ignition.

18. Definitions
• Combustible Liquid
• Combustible liquid means any liquid having
a flash point at above 100°F (37.8 °C).
• Combustible liquids are divided into two
classes:
– Class II
– Class III

19. Definitions
• Class II Liquids
• Class II liquids shall include those with a
flash point at or above 100°F (37.8°C) and
below 140°F (60°C)

20. Definitions
• Class III Liquids
• Class III liquids shall include those with
flash points at or above 140°F (60°C).
• Class III are divided into two classes:
– Class IIIA
– Class IIIB

21. Definitions
• Class IIIA Liquids
• Class III liquids shall include those with
flash points at or above 140°F (60°C) and
below 200°F (93.3°C)

22. Definitions
• Class IIIB Liquids
• Class IIIB liquids shall include those with a
flash point at or above 200°F (93.3°C).
• This section does not regulate Class IIIB
liquids.

23. Definitions
• NOTE:
• When a combustible liquid is heated to
within 30°F (16.7°C) of its flash point, it
shall be handled in accordance with the
requirements for the next lower class of
liquids

24. Definitions
• Flammable Liquid
• Flammable liquid means any liquid having
a flash point below 100 °F (37.8 °C)
• Flammable liquids shall be known as
Class I liquids

25. Definitions
• Class I liquids are divided into three
classes:
• Class 1A
• Class 1B
• Class 1C

26. Definitions
• Class 1A
• Class 1A shall include liquids having flash
points below 73 °F (22.8°C) and having a
boiling point below 100 °F (37.8°C)
• Examples: Ethyl Ether, Isopropyl Chloride,
Pentane

27. Definitions
• Class 1B Liquids
• Class 1B shall include liquids having flash
points below 73°F (22.8°C) and having a
boiling point at or above 100°F (37.8°C)
• Example: Acetone, Gasoline, Toluene

28. Definitions
• Class 1C
• Class 1C shall include liquids having flash
points at at or above 73°F (22.8°C) and
below 100°F (37.8°C)
• Examples: Amyl Alcohol, Naphtha, Xylene

29. Flash
Point
200°F
140°F
100°F
73°F
Boiling Point
100°F
IA IB
IC
II
IIIA
Combustible
Flash Point
> 100°F
Flammable
Flash Point
< 100°F

30. Definitions
• Portable Tank
• Portable tank shall mean a closed container
having a liquid capacity over 60 U.S.
gallons and not intended for fixed
installation

31. Definitions
• Safety Can
• Safety can means an approved container, of not
more than 5 gallons capacity, having a spring-
closing lid and spout cover and so designed that it
will safely relieve internal pressure when subject to
fire exposure

32. Definitions
• Vapor Pressure
• Vapor Pressure is a measure of a liquid’s
propensity to evaporate.
• The higher the vapor pressure, the more
volatile the liquid and, thus, the more
readily the liquid gives off vapors

33. Flammable (Explosive) Limits
• Flammable Range
• The range of a combustible vapor or gas-air
mixture between the upper and lower flammable
limits.
• Also, known as the “explosive range.”

34. Flammable (Explosive) Limits
• Lower Flammable Limit
• The lowest concentration at which a combustible
gas forms a flammable mixture.
• Below the LFL there is too little combustible fuel
to sustain a flame.
• Also, known as “Lower Explosive Limit or LEL.”

35. Flammable (Explosive) Limits
• Upper Flammable Limit
• The highest concentration at which a combustible
gas forms a flammable mixture.
• Above the UFL there is too little oxygen to sustain
a flame. Better known as “too rich” to burn.
• Also, known as “Upper Explosive Limit or UEL.”

36. Flammable (Explosive) Limits
• Hazardous Material LFL UFL
• Butane 1.9 8.5
• Ethylene Oxide 3.0 100.0
• Gasoline 1.4 7.6
• Hydrogen 4.0 75.0
• Isopropyl Alcohol 2.0 12.7
• Propane 2.1 9.5

37. Flammable and Combustible Liquids

38. 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

39. Classes of Some Flammable Liquids
CLASS IA
CLASS IB
CLASS IC
Common Name Flash Point (o
F)
Ethyl Ether -49
Gasoline -45
Methyl Ethyl Ketone 21
Toluene 40
Xylene 81-115
Turpentine 95

40. Program Components
• Control of ignition sources
• Proper storage
• Fire control
• Safe handling
A good plan for safe use of flammable and
combustible liquids contains at least these
components:

41. Sources of Ignition
• Open flames
• Smoking
• Static electricity
• Cutting and welding
• Hot surfaces
• Electrical and mechanical sparks
• Lightning
Must take adequate precautions to prevent ignition of
flammable vapors. Some sources of ignition include:

42. 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

43. Industrial Plants – Grounding
• Class I liquids shall
not be dispensed into
containers unless the
nozzle and container
are electrically
interconnected

44. 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

45. Grounding
• Eliminates a difference in static
charge potential between
conductive objects and ground
• Although bonding will eliminate
a difference in potential between
objects, it will not eliminate a
difference in potential between
these objects and earth unless one
of the objects is connected to
earth with a ground wire

46. Ventilation
Always provide adequate ventilation
to reduce the potential for ignition of
flammable vapors.

47. Storage Fundamentals
• Identify incompatible chemicals – check the
Material Safety Data Sheet
• Isolate and separate incompatible materials
– Isolate by storing in another area or room
– Degree of isolation depends on quantities,
chemical properties and packaging
– Separate by storing in same area or room, but
apart from each other

48. Storage of Flammable
and Combustible Liquids
• Storage must not limit the use of
exits, stairways, or areas normally
used for the safe egress of people
• In office occupancies:
– Storage prohibited except that
which is required for maintenance
and operation of equipment
– Storage must be in:
• closed metal containers inside
a storage cabinet, or
• safety cans, or
• an inside storage room
Inside storage room

49. 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

50. Flame Arrester Screen
• Prevents fire flashback into can
contents
• Double wire-mesh construction
• Large surface area provides rapid
dissipation of heat from fire so
that vapor temperature inside can
remains below ignition point

51. 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

52. Fire Control
• Suitable fire control devices, such as
small hose or portable fire extinguishers
must be available where flammable or
combustible liquids are stored
• Open flames and smoking must not be
permitted in these storage areas
• Materials which react with water must
not be stored in the same room with
flammable or combustible liquids

53. Transferring Flammable Liquids
1. Through a closed piping system
2. From safety cans
3. By gravity through an approved self-
closing safety faucet
4. By means of a safety pump
Since there is a sizeable risk whenever flammable
liquids are handled, OSHA allows only four
methods for transferring these materials:

54. Self-Closing Safety Faucet
• Bonding wire
between drum and
container
• Grounding wire
between drum and
ground
• Safety vent in drum

55. 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

56. Waste and Residue
Waste drum with
disposal funnel
Safety disposal can Oily-waste can
(self-closing lid)
Combustible waste and residue must be kept to a minimum,
stored in covered metal receptacles and disposed of daily.

57. Container and Portable Tank
Storage
• This section applies only to the storage of
flammable and combustible liquids in
drums or other containers not exceeding
60 gallons individual capacity and portable
tanks of less than 660 gallons individual
capacity.

58. Container and Portable Tank
Storage
• Only approved containers and portable tanks may
be used to store flammable and combustible
liquids
• Metal containers and portable tanks must meet
DOT requirements

59. Design, Construction and
Capacity of Storage Cabinets
• Not more than 60 gallons of Class I and/ or Class
II liquids, or not more than 120 gallons of Class
III liquids may be stored in an individual cabinet

60. Design, Construction and
Capacity of Storage Cabinets
• The standard permits both metal and
wooden storage cabinets
• Cabinets shall be designed and constructed
to limit internal temperatures to not more
than 325°F when subject to a standardized
10-minute fire test

61. Design, Construction and
Capacity of Storage Cabinets
• The bottom, top, door, and sides of metal
cabinets shall be at least 18 gauge sheet
metal and double walled with a 1 ½ -inch
air space
• The door shall be provided with a three
point lock and the door sill shall be raised at
least 2-inches above the bottom of the
cabinet

62. Design and Construction of
Inside Storage Rooms
• Construction is to comply with test
specifications outlined in NFPA 251
• Openings to other rooms or buildings shall
be provided with non-combustible liquid-
tight raised sills or ramps at least 4-inches
in height, or the floor in the storage area
shall be at least 4-inches below the
surrounding floor

63. Design and Construction of
Inside Storage Rooms
• Opening shall be provided with approved
self-closing fire doors
• The room shall be liquid tight where the
floor joins the floor
• Electrical wiring for Class I liquids will
comply with Class I, Division 2 hazardous
locations

64. Design and Construction of
Inside Storage Rooms
• In each storage room, an aisle of at least
3 feet in width will be maintained
• Containers over 30 gallons capacity shall
not be stacked
• Containers will be at least 3 feet from
sprinkler heads

65. Fire Control
• At least one portable fire extinguisher having a
rating of not less than 12-B units shall be located
outside of, but not more than 10 feet from, the
door opening into any room used for storage.

66. Maximum Quantities
• The quantity of liquid
that may be located
outside of an inside
storage room or
storage cabinet in a
building or in any one
fire area of a building
shall not exceed:
– 25 gallons of Class IA
liquids in containers
– 120 gallons of Class
IB, IC, II, or III liquids
in containers
– 660 gallons of Class
IB, IC, II, or III liquids
in a single portable
tank.

67. Service Stations
• No smoking or open
flames in areas used
for fueling, servicing
fuel, etc.
• Conspicuous signs
must be posted.

68. Liquid Transfer
• If gravity transfer is
used, must be through
an approved self-
closing valve.
• Transferring by means
of air pressure on the
container or portable
tanks shall be
prohibited.

69. Handling Liquids
• Flammable liquids
shall be kept in
covered containers
when not actually in
use.

70. Housekeeping
• Combustible waste
and residue shall be
kept to a minimum,
stored in covered
metal receptacles, and
disposed of daily

71. Safe Handling Fundamentals
• Carefully read the manufacturer’s label on
the flammable liquid container before
storing or using it
• Practice good housekeeping in flammable
liquid storage areas
• Clean up spills immediately, then place the
cleanup rags in a covered metal container
• Only use approved metal safety containers
or original manufacturer’s container to store
flammable liquids
• Keep the containers closed when not in use
and store away from exits or passageways

72. 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

73. Spray Finishing
1910.107

74. Definitions
• Aerated Solid Powders
– Aerated powders shall mean any powdered
material used as a coating material which shall
be fluidized within a container by passing air
uniformly from below. It is common practice to
fluidize such materials to form a fluidized
powder bed and then dip the part to be coated
into the bed in a manner similar to that used in
liquid dipping. Such beds are also used as
sources for powder spray operation

75. Definitions
• Spraying Area
• Any area in which dangerous quantities of
flammable vapors or mists, or combustible
residues, dusts, or deposits are present due
to the operation of spraying processes.

76. Definitions
• Spray Booth
• A power-ventilated structure provided to
enclose or accommodate a spraying
operation to confine and limit the escape of
spray, vapor, and residue, and to safely
conduct or direct them to an exhaust system

77. Definitions
• Waterwash spray booth
• A spray booth equipped with a water
washing system designed to minimize dusts
or residues entering exhaust ducts and to
permit the recovery of overspray finishing
material

78. Definitions
• Dry spray booth
• A spray booth not equipped with a water
washing system as described in
subparagraph (4) of this paragraph.

79. Definitions
• Dry spray booth
• A dry spray booth may be equipped with
– distribution or baffle plates to promote an even flow of
air through the booth or cause the deposit of overspray
before it enters the exhaust duct; or
– overspray dry filters to minimize dusts or residues
entering exhaust ducts; or
– where dry powders are being sprayed, with powder
collection systems so arranged in the exhaust to capture
oversprayed material.

80. Separation of Operations
• Each spray booth shall be separated from
other operations by:
• not less than 3 feet or
• by a partition or wall to reduce danger
3 feet
3 ft 8 feet

81. Sources of Ignition
• There will be no open flame or spark
producing equipment in any spray area nor
within 20 feet
• Space heating appliances, steam pipes, or
hot surfaces shall not be located in the spray
area

82. Electrical
• Class I or Class II, Division 1 Locations
• The interior of spray booths or rooms
• The interior of exhaust ducts
• Any area in the direct path of spray
operations

83. Electrical
• Class I or Class II, Division 2 Locations
• For open spraying, all space outside of but
within 20 feet horizontally and 10 feet
vertically
Spray Area
20’

84. Closed Top/Open Face
Booth

85. Enclosed Spray Booth or
Room

86. Open Spraying
Locations

88. 1910.119(a) Purpose
• This section contains requirements for preventing or
minimizing the consequences of catastrophic releases
of:
– Toxic,
– Reactive,
– Flammable, or
– Explosive chemicals
• These releases may result in toxic, fire or explosion
hazards

89. 1910.119(a)(1)Application
• A process which involves a chemical at or above the
specified threshold quantities listed in Appendix A
• A process which involves a flammable liquid or gas
(as defined in 1910.1200(c) of this part) on site in one
location, in a quantity of 10,000 pounds (4535.9 kg) or
more

90. Review
• What is a flammable liquid?
• What is a combustible liquid?
• A Class 1A flammable liquid has a flash
point of less than?

91. Review
• What is the maximum amount of a 1A
liquid that can be stored outside of a
flammable storage cabinet or room?
• A 12B fire extinguisher must be located
within _______ feet of flammable liquid
storage room.

92. Review
• Spray finishing can be a hazardous activity.
– True or False
• Each spray booth must be separated by
___ feet or a wall or partition from other
operations.
• Spray booths require ___________
electrical installations.