OSHA Compliance with Flammable and Combustible Liquids

Flammable Liquids Standard: How
to Prevent Explosions & Fire
Hazards and Stay in Compliance
Presented by:
Bernard L. Fontaine, Jr., CIH, CSP
The Windsor Consulting Group, Inc.

Copyright © 2014 The Windsor Consulting Group, Inc.

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 NFPA approved
equipment and practices per
OSHA standards
• Webinar does not cover risks
on combustible dust or
flammable gas or solids

Session Objectives
• You will be able to:
– Identify a flammable and
combustible liquids
– Know the hazards of
flammable and
combustible liquids and
the types of controls to
prevent their ignition
– Procedures to safely store,
dispense, and handle these
liquids


What’s the Big Deal?
• Flammable and combustible
liquids are easily ignited
• Ignite with explosive force
• Burn readily and give off
twice the heat as paper or
wood fire
• Common materials taken for
granted or used carelessly


Fire Tetrahedron

Fuel

Combustible
Flammable
Liquid

Heat
Source

Increased
Surface
Temperature
Production
of
Vapor

Oxygen
Sustained
Combustion

Suitable
Chemical
Reaction

Flame
Established


Flammable Liquids
• Flammable—flashpoint below 100˚F (37.8˚C)
– Isopropyl alcohol
– Propane
– Solvents such as acetone, MEK, paint thinner,
varnish
– Fuels such as gasoline
– Aerosol cans


Combustible Liquids
• Flashpoint at or above 100 F
– Oil, kerosene
– Greases and lubricants
– Oil-based paints

• Although combustible
liquids have higher flash
points than flammable
liquids, they can pose
serious fire and/or
explosion hazards when
heated.

Classifying Flammable Liquids
Flashpoint

Category
N/A (1910.106 Not Applicable) unless

199.4 F

140 F
Flammable
73.4 F

heated for use to within 30 F of its FP,
then treat as Category 4

Category 4
Category 3
Category 1

Category 2

< 95 F > Boiling Point

Classifying Flammable Liquids


Classifying Combustible Liquids


Classes of Flammable and
Combustible Liquids

Flash Point (oF)

200

IIIA
140

Combustible
(FP > 100oF)

II
100

Flammable
(FP < 100oF)

73

IA

IB

100
Boiling Point (oF)

Classes of Flammable Liquids
Common Name

Flash Point (oF)

CLASS IA

Ethyl Ether

-49

CLASS IB

Gasoline
Methyl Ethyl Ketone
Toluene
Benzene

-45
21
40
12

CLASS IC

Xylene
Turpentine
Hydrazine
Styrene

81-115
95
99
88

Classes of Combustible Liquids
Common Name

CLASS II

Acetic Acid
Naphtha
Stoddard Solvent

Flash Point (oF)
103
100-109
102-110

CLASS IIIA Cyclohexanol
Formic Acid
Nitrobenzene

154
122
190

CLASS IIIC Formalin
Picric Acid

185
302

What’s the Hazard?
• Flammable and
combustible liquids
vaporize and form
flammable mixtures
with air when:
– Exposed to air
(containers are left
open)
– Leaks or spills occur
– Heated or aerosolized


Degree of Hazard Risk
• Determined by:
– The flashpoint , boiling point,
and the vapor pressure of the
solvent
– The vapor’s concentration in
the air
– The presence of potential
ignition sources
– Remember—vapors burn or
explode, not the liquid


Flashpoint

• The lowest temperature at which a liquid gives off
enough vapors at its surface to form an ignitable
mixture in air
• Low flashpoint = high flammability
• Flammable liquids flashpoint is
<100˚F and more dangerous
• Combustible liquids flashpoint is ≤100˚F and <
200˚F

Boiling Point
• The temperature of the liquid at which the vapor
pressure equals atmospheric pressure


Vapor Pressure
• Pressure exerted by a vapor on the surface of the
liquid

• Amount of vapor that accumulates on surface of
the liquid depends on temperature and the
flammable or combustible liquid


Flammable Range


Flammable Range
• Not all mixtures of fuel and air will burn
• Solvents have variable flammable range
• In order to burn, the fuel/air ratio must be
within the flammable range, between the:
– Lower Explosive
Limit (LEL)
– Upper Explosive
Limit (UEL)

Image credit: Tom Ouimet


Measuring Flammable and
Combustible Vapors
•
•

•

Real-time instruments
read out in percent of LEL
A reading of 25% LEL
indicates the fuel-air
mixture is 1/4 of the way to
the lowest fuel
concentration that can
burn
Never enter a >25% LEL
atmosphere


Sources of Ignition
• Some potential sources of
ignition are:
–
–
–
–
–
–
–
–

Open flame
Smoking
Welding and cutting
Hot surfaces
Internal combustion engines
Electrical/mechanical spark
Lightning
Static electricity

• Flammable vapors can travel
some distance to a source of
ignition and flash back

Static Electricity
• Generated when a fluid
flows through pipe or
from an opening into a
tank
• Main hazards are fire and
explosion from sparks
containing enough vapor
to ignite flammable vapors
• Bonding and grounding of
storage containers is
necessary to dissipate
any stored static charge

Prevent Fire and Explosion
• Eliminate ignition sources prevent flames, sparks, and
arcs
• Eliminate static electricity ground or bond containers
• Minimize vapor concentrations

Image credit: Tom Ouimet


Bonding Containers
• Physically connect two
conductive objects
together with a bond
wire and clip to remove
a difference of static
charge between them
• Bonding wires are
placed between two
containers during liquid
filling or dispensing
operations unless a
metallic path is place in
between them

Grounding Containers
• 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
and earth.
• Unless one of the objects
is connected to earth with
a ground wire.

Industrial Plants
Category 1, 2, or 3 (FP <100 F) flammable
liquids shall not be dispensed into containers
unless the nozzle and container are electrically
interconnected
(bonded and grounded)


Warning Signs and Labels
• Signs identify areas where flammable and/or
combustible liquids are stored, transferred, and
used
• Individual containers are labeled:
– Global harmonization pictograms, hazard and
precautionary statements, signal words
– DOT label
– HMIS® labels
– National Fire Protection
Association (NFPA) labels


Read Fine Print on Labels
• Look for special warnings:
– Special handling or storage
instructions
– Inhalation hazards - many
flammable solvents are toxic
and hazardous to inhale
– Skin hazards – some toxic
solvents absorb through skin,
cause irritation or allergic rash,
or directly damage the skin
– Select and use impermeable
gloves, protective clothing,
and/or respirator

Only an example


Safety Data Sheet (SDS) - Primary
Source of Chemical Information
• Special storage and
handling precautions
• Dispensing techniques
• Flammability limits
• Reactivity hazards
• Fire-fighting protective
equipment and instructions
• Hazardous combustion
products


GHS HAZCOM and DOT Pictograms


NFPA Labeling System

4
2

3


Container and Portable Tank
Storage
Applies only to the storage of flammable liquids
in drums or other containers (including
flammable aerosols) not exceeding 60 gallons
individual capacity and those portable tanks not
exceeding 660 gallons individual capacity
NOTE: Exceptions apply.
Refer to standard for more information.


Container and Portable Tank
Storage
• Only approved containers and portable tanks
shall be used.
• Each portable tank shall be provided with one
or more devices installed in the top with
sufficient emergency venting capacity to limit
internal pressure under fire exposure
conditions.

• Flammable liquid containers shall be in
accordance with Table H-12.


Containers - Table H-12
Container type

Category 1

Category 2

Category 3

Category 4

Glass or approved plastic

1 pt.

1 qt.

1 gal.

1 gal.

Metal
(other than DOT drums)

1 gal.

5 gal.

5 gal.

5 gal.

Safety cans

2 gal.

5 gal.

5 gal.

5 gal.

Metal drums
(DOT specifications)

60 gal.

60 gal.

60 gal.

60 gal.

Approved portable tanks

660 gal.

660 gal.

660 gal.

660 gal.

Note: Container exemptions: (a) Medicines, beverages, foodstuffs, cosmetics, and other common consumer items,
when packaged according to commonly accepted practices, shall be exempt from the requirements of
1910.106(d)(2)(i) and (ii).


Use Safe Storage Practices
• No open flames,
smoking, sparks, or
welding
• Keep away from sunlight
• Ventilate well
• Store oxidizers
separately
• Use secondary
containment
• Return to storage
immediately after use


Flammable 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 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 two
inches above the bottom of the
cabinet

Maximum of three (3) cabinets in any fire area

Flammable Storage Cabinets
Chemical storage cabinets
used for flammables often
come with capped bung
openings that allow
ventilation. It is NOT
required by OSHA or any
regulatory agency
Cabinet manufacturers
include venting bungs for
users who are required to
vent by state or local fire
codes, individual company
or insurance carrier policy

Storage of Flammable and
Combustible Liquids
• Store away from exits,
stairways, or areas normally
used for egress of people
• In offices storage prohibited
except that which is required
for maintenance and
operation of equipment

Inside storage room

• Storage must be in: closed metal containers
inside a storage cabinet, safety cans,
designated fire area or properly designed
inside storage room


NFPA/NEC Hazardous Locations
NFPA and NEC define hazardous material categories
for flammable gases and vapors, and combustible
dusts, fibers, and flyings

• Class I areas for flammable vapors and liquids
___________________________________________________________________________________________

• Division 1 – Normal operating conditions
• Division 2 – Abnormal or upset conditions

• Groups A-G liquids and Groups A-D environments


NFPA/NEC Hazardous Locations
Examples of Class I – Division 1 and 2 locations

•
•
•
•

Petroleum refineries and spray finishing areas
Aircraft hangers and fuel servicing areas
Utility gas plants
Storage and handling of LPG or natural gas


Inside Storage Rooms


In ―inside‖ storage rooms
• Maintain one clear aisle
at least 3 feet wide

• Containers over 30 gallons
capacity shall not be
stacked one upon the other
• Dispensing shall be by
approved pump or self-closing faucet only
• Storage shall comply with Table H-13


NFPA 30 Flammable and
Combustible Liquids Code
• Fire resistant rating of two (2)
hours for walls, floor, and ceiling

• Class B fire doors
• Automatic fire protection
systems

• Mechanical ventilation
depending on stored quantity
• Class I – Division 2 electrical
wiring and light fixtures

Explosion-Proof (EX) Material Handling Equipment


Storage Outside an Inside
Storage Room
Storage of drums
• 55 gallon drums should be
stored separate storage area
away from heat and sunlight
• Maximum size of drum that
should be stored outside and
inside storage room is 5 gallons


Storage Inside Rooms –
Table H-13
Fire Protection (1)
Fire Resistance
Provided

Maximum Size

Total
Allowable
Quantities –
Gal./Ss.
Ft/Floor Area

Yes

2 hours

500 Sq. Ft.

10

No

2 hours

500 Sq. Ft.

4*

Yes

1 hour

150 Sq. Ft.

5*

No

1 hour

150 Sq. Ft.

2

Footnote(1) Fire protection system shall be sprinkler, water spray, carbon dioxide, or other
system. *Note: These numbers are shown incorrectly in 29 CFR 1910.106.


Office Occupancies
Storage prohibited except if it is required for
maintenance, operation of building and operation
of equipment, and then…
Shall be kept in closed metal containers stored
in a storage cabinet or in safety cans or in an
inside storage room


Warehouses and Storage
Buildings
• General purpose public warehouses, and
• Flammable liquid warehouses or storage
buildings
Refer to Table H-14 – Indoor container
storage, or Table H-15 – Indoor portable tank
storage


Safety Cans for Storage and
Transfer
• Approved container of
not more than five gallon
capacity.
• Spring-closing lid and
spout cover.
• Safely relieves internal
pressure when exposed
to fire.


Flame Arrester Screen
• Prevents fire flashback
into can contents
• Double wire-mesh
construction
• Large surface area:
-Provides rapid
dissipation of heat from
fire
-Vapor temp inside can
remains below ignition
point

Dispense Flammable Liquids
Safely
• Ensure primary container
or drum is grounded and
bonded
• Transfer liquid with a hand
pump or grounded,
explosion-proof motorized
pump
• Use spark-proof tools
• Perform transfer in well
vented area away from all
ignition sources

Automatic hazardous materials dispenser


Transferring Flammable Liquids
There is a sizeable risk whenever flammable
liquids are handled. OSHA allows only four
methods for transfer:
(a) Through a closed piping system
(b) From safety cans
(c) By gravity, through an approved self-closing
safety faucet
(d) By means of a safety pump


Handle Liquids and Containers
Safely
•
•
•
•

Use only approved containers—never use glass
Close containers when not in use
Label containers properly
Take only the amount needed for the job and
use with adequate ventilation


Handle Liquids and Materials
Safely
• Put rags soaked with flammable liquids in
approved, closed containers
• Avoid mixing flammable and combustible solvents
• Do not weld or torch empty containers


Self-Closing Safety Faucet

• Bonding wire between
metal drum and metal
container
• Grounding wire between
metal drum and ground
• Safety vent in drum


Safety Pump
• Faster and safer than
using a faucet
• Spills are less likely.
• No separate safety vents
in drum required

• Installed directly in drum
bung opening
• Some pump hoses have
integral bonding wires.


Waste and Residue
• Combustible waste and residue must be kept to
a minimum, stored in covered metal receptacles
and disposed of daily

Waste drum with
disposal funnel

Safety disposal
can

Oily-waste can
(self-closing lid)


Storage Outside Buildings
• Maximum of 1,100 gallons of flammable liquids
• Area shall be protected against tampering or
trespassers

• Area shall be graded in a manner to divert
possible spills away from buildings
• Storage shall comply with:

Table H-16 – Outdoor container
storage, or
Table H-17 – Outdoor portable tank
storage

Tank Storage
• Shall be made of steel or other approved
nonflammable materials
• Other materials are permitted for underground
use

• Concrete tanks (must have a special interior
lining) and be designed with sound engineering
practices
• Operating pressures must
never exceed the design
pressure


Tank Storage
Metal tanks

• Welded, riveted, and caulked, brazed, or
bolted, or constructed by use of a
combination of these methods
Filler metals used in tank brazing

• Nonferrous metal or alloy having a melting
point above 1000 F and below that of the
metal joined


Tank Storage
Atmospheric tanks

• Shall be built in accordance with acceptable
standards
• Not exceed 2500 gallons, if originally
designed for underground but placed above
ground
• Not be used to store liquids at or above
their boiling points


Tank Storage
Low pressure tanks and pressure vessels

• Normal operating pressure of the tank shall not
exceed the design pressure of the tank.
• May be used as atmospheric tanks.

• Pressure vessels may be used as low-pressure
tanks.
• Shall be built in accordance with acceptable
standards.


Tank Storage
Outside aboveground tanks
• Spacing - (shell-to-shell) between any two
flammable liquid above ground storage
tanks shall be no less than three feet

• Unstable liquids – Distance between tanks
shall not be less than ½ the sum of their
diameter


Tank Storage
Outside aboveground tanks
Liquefied Petroleum Gas (LPG) - containers
next to flammable storage tanks shall have a
minimum of 20 feet of separation

Must be a
minimum of
20 feet
between
these tanks


Tank Storage
Normal and emergency venting

• Required on all above ground tanks
• Enough venting to prevent vacuum or
rupture

• Refer to Table H-10 for venting flow rates


Results of Improperly Vented Tank

Photo courtesy of the NFPA Flammable and Combustible Liquids Code Handbook

Tank Storage
Drainage, dikes and walls

• Area surrounding aboveground tanks shall
be provided with drainage or be diked to
prevent accidental discharge of liquid.
• If diked, the area should be able to hold the
capacity of a full tank.
• Walls of diked area shall be of earth, steel,
concrete or solid masonry designed to be
liquid tight.


Tank Storage
Supports, foundations and anchorage for all
tank locations
• Tank supports shall be installed on firm
foundations.
• Steel supports or exposed piling shall be
protected by materials having a fire
resistance rating of not less than 2 hours.
• Tanks shall rest on the ground or on
foundations made of concrete, masonry,
piling, or steel.


Tank Storage
Supports, foundations, and anchorage in flood
zones

• When a tank is located in an area that may
be subjected to flooding, check established
flood stage markings
• Liquid level in the tank must never go below
the established maximum flood line
Please note: There are many requirements for
tanks that are located in flood zones. For more
in-depth detail, refer to 1910.106(b)(5)(vi)


Tank Storage
Ignition sources
Precautions to prevent the ignition of flammable
vapors includes open flames; lightning; smoking;
cutting and welding; hot surfaces; frictional heat;
static, electrical, and mechanical sparks;
spontaneous ignition, including heat-producing
chemical reactions; and radiant heat.


Pipes, Valves, and Fittings
The design (including selection of materials)
fabrication, assembly, test, and inspection of
piping systems containing flammable liquids shall
be suitable for the expected working pressures
and structural stresses


Personal Protective Equipment
(PPE)
• Eye—goggles for splash
hazard
• Hand—solvent-resistant
chemical protective
gloves
• Body—chemical
protective clothing such
as an apron or coveralls
• Lungs—respirator


Common First-Aid Procedures
• Inhale vapors–move to
fresh air
• Splash liquid to the face or
eyes—flush the eyes/face
for 15 minutes
• Splash to skin—wash skin
with soap and water
• Ingest liquid—consult the
MSDS, and call a doctor


Fire Response
• Remove yourself from
physical danger
• Notify others, trigger the
fire alarm
• Use a Type ABC fire
extinguisher
• Call for help
• Continually evaluate for
evacuation
• Don’t fight structural fires
yourself

Spill Response
• Report all spills immediately
and clean up small spills
• Large spills require a
specialized response team
• Eliminate ignition sources
• Evacuate the area
• Help clean up only if
properly trained


Key Things to Remember
• Flammable and combustible liquids can ignite
with explosive force
• Keep away from ignition sources
• Follow proper storage, dispensing, and
handling procedures
• Use only approved
containers that are
properly labeled.
• Review labels and
SDSs for additional
information

Class Exercise
Liquid

Flashpoint
Boiling Category
(° F)
Point (° F)

Diesel Fuel #2

126

320

Toluene

40

231

Motor Oil

392

599

Isoamyl Acetate

77

288

Ethyl Ether

- 49

94

Phenol

174

360

NOTE: Use the FP (Flash Point) and the BP (Boiling Point) to determine the Category using
the Flammable Liquid Chart.

Class Exercise (Answers)
Liquid

Flashpoint
Boiling Category
(° F)
Point (° F)

Diesel Fuel #2

126

320

3

Toluene

40

231

2

Motor Oil

392

599

N/A

Isoamyl Acetate

77

288

3

Ethyl Ether

- 49

94

1

Phenol

174

360

4

NOTE: Use the FP (Flash Point) and the BP (Boiling Point) to determine the Category using
the Flammable Liquid Chart.

Summary
In this webinar, we discussed the following:

• Scope of the OSHA general industry and
construction standards
• Four elements of the fire tetrahedron
and how the standards aim to reduce risk and
interrupt those elements
• Classifying flammable liquids

• Storage requirements for liquids
covered under the standard


References
• OSHA General Industry – 29 CFR 1910.106 –
Flammable Liquids
• OSHA General Industry – 29 CFR 1910.107 –
Spray Finishing Using Flammable/Combustible
Materials
• OSHA Construction Industry – 29 CFR 1926.152
Fire Protection & Prevention - Flammable Liquids
• National Fire Protection Association (NFPA) 30
Flammable and Combustible Liquids Code
• NFPA 45 Fire Protection for Laboratories Using
Chemicals
• NFPA 70 – Classification of Hazardous Locations
• National Electrical Code (NEC)– Classification of
Hazardous Locations

Flammable Liquids Standard: How
to Prevent Explosions & Fire
Hazards and Stay in Compliance

Questions or Comments?


OSHA Compliance with Flammable and Combustible Liquids

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