OSHA Compliance with Flammable and Combustible Liquids

Flammable Liquids Standard: How to Prevent Explosions & Fire

Hazards and Stay in CompliancePresented by:

Bernard L. Fontaine, Jr., CIH, CSPThe 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

SustainedCombustion

Flame Established

Production of

Vapor

IncreasedSurface

Temperature

CombustibleFlammable

Liquid

Oxygen

HeatSource

Fuel

SuitableChemicalReaction


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.


Flashpoint Category

N/A (1910.106 Not Applicable) unless heated for use to within 30°F of its FP,

then treat as Category 4

Flammable

Category 4

Category 3

Category 1 Category 2

< 95° F > Boiling Point

199.4°F

140°F

73.4°F

Classifying Flammable Liquids


Classifying Flammable Liquids


Classifying Combustible Liquids


Classes of Flammable and Combustible Liquids

Flas

h Po

int (

o F)

200

IIIA

II140

10073

IA IB

Combustible(FP > 100oF)Flammable(FP < 100oF)

Boiling Point (oF)100


CLASS IA

CLASS IB

CLASS IC

Common Name Flash Point (oF)

Ethyl Ether -49

Gasoline -45Methyl Ethyl Ketone 21Toluene 40Benzene 12

Xylene 81-115Turpentine 95Hydrazine 99Styrene 88

Classes of Flammable Liquids


CLASS II

CLASS IIIA

CLASS IIIC

Common Name Flash Point (oF)

Acetic Acid 103

Naphtha 100-109Stoddard Solvent 102-110

Cyclohexanol 154Formic Acid 122Nitrobenzene 190

Formalin 185Picric Acid 302

Classes of Combustible Liquids


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

2 3

4


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.


• 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.

Container and Portable Tank Storage


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 fromsunlight

• Ventilate well• Store oxidizers

separately• Use secondary

containment• Return to storage

immediately after use


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

Flammable Storage Cabinets


• 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

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

Inside storage room

Storage of Flammable and Combustible Liquids


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

NFPA/NEC Hazardous Locations

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 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 Outside an Inside Storage Room


Storage Inside Rooms – Table H-13

Fire Protection (1) Provided Fire Resistance 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 OccupanciesStorage 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


• 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

Warehouses and Storage Buildings


• Approved container of not more than five gallon capacity.

• Spring-closing lid and spout cover.

• Safely relieves internal pressure when exposed to fire.

Safety Cans for Storage and Transfer


• 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

Flame Arrester Screen


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


(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

There is a sizeable risk whenever flammable liquids are handled. OSHA allows only four methods for transfer:

Transferring Flammable Liquids


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


• Bonding wire between metal drum and metal container

• Grounding wire between metal drum and ground

• Safety vent in drum

Self-Closing Safety Faucet


• 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.

Safety Pump


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

Waste and Residue


• 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

Storage Outside Buildings


• 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


http://www.fedcenter.gov/_storage/Photos/538.jpg

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


Tank StorageAtmospheric 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 StorageLow 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 StorageOutside 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 StorageOutside 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 StorageNormal 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 StorageDrainage, 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 StorageSupports, 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 StorageSupports, 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

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

Liquid Flashpoint (° F)

Boiling Point (°

F)

Category

Diesel Fuel #2 126 320Toluene 40 231Motor Oil 392 599Isoamyl Acetate

77 288

Ethyl Ether - 49 94Phenol 174 360


Class Exercise (Answers)

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

Liquid Flashpoint (° F)

Boiling Point (°

F)

Category

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


SummaryIn 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 LocationsCopyright © 2014 The Windsor Consulting Group, Inc.

Questions or Comments?


Flammable Liquids Standard: How to Prevent Explosions & Fire

Hazards and Stay in Compliance

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OSHA Compliance with Flammable and Combustible Liquids