Hanover Risk Solutions
Storage of Flammable and
Combustible Liquids in Containers
The storage of flammable and combustible liquids presents a serious fire protection challenge.
The presence of these liquids in storage areas significantly adds to the fire load of a property.
During a fire, flammable liquids containers may fail and spill their contents, creating more fuel for
the fire. This report provides loss control considerations for the incidental storage of flammable
and combustible liquids, in containers, in general purpose warehouses and mercantile, office, and
institutional occupancies.
While storage locations for flammable and
liquid storage areas, such as cutoff rooms or
combustible liquids, such as kerosene,
liquids warehouses.
motor oil, paints, paint thinner, and rubbing
alcohol, can be found in any type of occupancy, such locations should be designed
and constructed to protect the liquids from
fire and to contain any fires that may occur
in the area. Containers for the storage of
flammable and combustible liquids may
be constructed of glass, plastic, and metal;
however, plastic containers are most often
used to package these liquids.
This report provides considerations for the
incidental storage of flammable and combustible liquids in occupancies not specifically designed as inside liquid storage areas,
such as warehouses, mercantile, office, and
institutional occupancies, as defined by the
2015 revision of NFPA 30, Flammable and
Combustible Liquids Code, published by the
National Fire Protection Association (NFPA).
The report does not include considerations
for the storage of flammable and combustible liquids in portable tanks, intermediate
bulk containers, outside locations, or inside
Terminology
NFPA 30 includes a system for categorizing
liquids as being flammable or combustible.
These liquid classifications are used for
determining the various requirements within
NFPA codes and standards. The system is
based primarily on the flash point of the
liquid, that is, the minimum temperature at
which sufficient vapor is given off the liquid
to form an ignitable mixture with air.
Flammable liquids, which are classified as
Class IA, IB, and IC, are liquids that have
flash points below 100°F (37.8°C) or less
and a vapor pressure not exceeding 40 psia
(2,068.6 mm Hg) at 100°F (37.8°C); combustible liquids, which are classified as Class II,
IIIA, and IIIB, are liquids that have flash points
of 100°F (37.8°C) or more. Class I liquids
are the most hazardous, from a fire safety
standpoint, while Class IIIB liquids are the
least hazardous of the classes. The following
describes the NFPA classification system:
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H A N OV E R R I S K S O LU T I O N S
General-Purpose Warehousing
• Class IA liquids are liquids that have flash
points below 73°F (22.8°C) and boiling
points below 100°F (37.8°C). Additionally,
unstable flammable liquids are treated as
Class IA liquids.
NFPA 30 permits limited quantities of flammable
and combustible liquid products to be stored
in General-Purpose Warehouses (GPWs) when
the warehouse is separated from other
occupancies by firewalls having a minimum fireresistance rating of four hours. GPWs should
be protected by an automatic sprinkler system,
designed and installed according to the provisions of NFPA 13, Standard for the Installation
of Sprinkler Systems, published by the National
Fire Protection Association (NFPA), for 20-ft.
(6-m) high storage of Class IV commodities
or by one of the protection designs found
in Chapter 16 of NFPA 30. Container size is
limited, as follows:
• Class IB liquids are liquids that have flash
points below 73°F (22.8°C) and boiling
points at or above 100°F (37.8°C).
• Class IC liquids are liquids that have flash
points at or above 73°F (22.8°C), but below
100°F (37.8°C).
• Class II liquids are liquids that have a flash
point at or above 100°F (37.8°C) and below
140°F (60°C).
• Class IIIA liquids are liquids that have a flash
point at or above 140°F (60°C), but below
200°F (93°C),
• Class IB and IC liquids— containers of 1.3
gal. (5 L) or less capacity.
• Class IIIB liquids are liquids that have a flash
point at or above 200°F (93°C).
• Class II liquids — containers of 5.3 gal. (20 L)
or less capacity.
It should be noted that the U.S. Department
• Class III liquids — containers of 60 gal. (230
L) or less capacity.
of Transportation’s (US DOT) Hazardous
In addition, the total quantity and storage
height of the liquids are limited to the following:
Materials Regulations (HMR) provides slightly
different definitions for flammable and
combustible liquids that are being transported.
• Class IB and IC liquids — maximum 660 gal.
(2,498 L) and 5 ft. (1.5 m) high.
Storage
• Class II liquid — maximum 1,375 gal. (5,204
L) and 5 ft. (1.5 m) high.
The storage requirements for flammable and
combustible liquids in containers will vary,
• Class IIIA liquid — maximum 2,750 gal.
(10,409 L) and 10 ft. (3.0 m) high.
depending on the type of occupancy, the
liquid’s classification, and the container size
• Class IIIB liquid — maximum 13,750 gal.
(52,044 L) and 15 ft. (4.6 m) high.
and construction. Containers for flammable
and combustible liquids should be specifically
Any storage exceeding these limitations should
be either in a dedicated liquid storage room,
meeting the design requirements of subsection
9.9 of NFPA 30, or in a detached liquids warehouse. Limited quantities of combustible
commodities also can be stored in a GPW
provided that the commodities are separated
from the liquids by a minimum distance of 8
ft. (2.4 m) horizontally, either by aisles or open
racks, and protected by an automatic sprinkler
system, as previously described.
listed, by an independent third party, as
suitable for the liquid to be stored.
NFPA requires that, in no case, should the
storage obstruct an exit or exit path, or
create a greater hazard to the occupants
of the premises. Also, regardless of the
occupancy, Class I liquids should not be
stored in basements. Additional requirements,
based on the occupancy type, include:
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H A N OV E R R I S K S O LU T I O N S
Storage in Plastic Containers
Mercantile Occupancies
NFPA 30 does not permit the storage of Class
I and Class II liquids in plastic containers in
GPWs, unless such storage is restricted to a
liquid storage room. However, subsection
12.8.4 of NFPA 30 does allow Class I and
Class II liquids in GPWs when the products are
packaged, as follows:
The storage and display of flammable and
• In individual containers having not more
than 50 percent water-miscible liquids,1
with the remaining solution not being a
Class I liquid;
• The maximum quantity of Class I and Class II
liquids that may be stored above the ground
floor is limited to 120 gal. (454 L) for areas
protected by an automatic sprinkler system.
This quantity should be reduced to 60 gal.
(230 L) when the area is not protected by an
automatic sprinkler system.
combustible liquid storage in mercantile
occupancies should be in accordance with
Chapter 10 of NFPA 30. Specific storage
requirements will vary based on the level of
fire protection provided, as follows:
• In individual containers not exceeding 16 oz.
(0.5 L) and having not more than 50 percent
water-miscible liquids;
• Class I and Class II liquids may not be stored
below grade.
• In packaging systems that are listed and
labeled for these liquids.
• Containers displayed and accessible to
the public are limited to 6 gal. (23 L), except
distilled spirits packaged in wooden barrels
or cask.
Dispensing of Liquids
Class I and Class II liquids should not be
dispensed in GPWs unless the operations are
performed in a room or area cutoff from all
other areas and designed for such operations.
Class I and Class II liquids should not be
transferred between containers unless both
containers are bonded and grounded. Proper
bonding/grounding is required to prevent the
buildup of static electricity produced by the
transfer of liquids. Provisions for bonding and
grounding include:
• Non-water-miscible Class II liquids in plastic
containers having a capacity of 1 gal. (3.8 L)
or more are limited to a total of 30 gal. (114
L) per storage pile and at least 50-ft. (15-m)
separation between storage arrangements.
This quantity may be doubled if the liquid
is stored in a listed flammables cabinet or is
protected by an automatic sprinkler system
having a design density of 0.60 gpm/ft.2
(24.4 mm/min).
• Connecting the containers to each other
electrically, before transferring the liquid.
Fire Protection
• Connecting both containers electrically to
earth ground, before transferring the liquid.
1
See Static Electricity, on Hanover’s Risk
Solutions website for additional information
on this topic.
The storage of flammable and combustible
liquids in mercantile occupancies is also limited
by the type of fire protection system present.
These limitations, which are detailed in Table
10.7.1 of NFPA 30, include:
water-miscible liquid mixes in all proportions with water. When
A
water-miscible flammable liquids are mixed with water, a homogeneous
solution is formed. The flash point, fire point, heat of combustion,
and the heat release rate of the solution will be different from the
pure flammable liquid.
• Unprotected storage is limited to no more
than: 60 gal. (230 L) of Class 1A liquids;
3,750 gal. (14,195 L), in any combination, of
Class IB, IC, II and IIIA liquids per location,
with a limitation of two locations per building
that are separated by one-hour fire rated
walls; and 15,000 gal. (56,781 L) of Class
IIIB liquids.
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H A N OV E R R I S K S O LU T I O N S
• Storage protected by an automatic sprinkler
system meeting the design requirements of
NFPA 13 for an Ordinary Hazard Group 2 is
limited to no more than: 120 gal. (454 L) of
Class 1A liquids; and 7,500 gal. (28,390 L), in
any combination, of Class IB, IC, II, and IIIA
liquids per location, with a limitation of two
locations per building that are separated
by one-hour fire rated walls. An unlimited
amount of Class IIIB liquids is permitted.
ducts, hoists, etc., should be grounded.
Storage quantities of greater than 30,000 gal.
(113,562 L), in any combination, of Class IB,
IC, II and IIIA liquids must be protected by
fire suppression systems, in accordance with
Chapter 16 of NFPA 30.
Heating systems for flammable liquid storage
Electrical equipment of the “explosion
proof” type, as defined by NFPA 70, should
be used in storage areas. Gas service should
comply with NFPA 54, National Fuel Gas
Code. Heating/air conditioning systems
should comply with the requirements of
NFPA 90A, Standard for the Installation of
Air Conditioning and Ventilating Systems.
areas should be of the type that does not
introduce an ignition source, such as steam
or hot water.
Smoking should not be permitted in areas
Table 10.7.1 also provides maximum storage
densities (i.e. gal./ft.2 [L/m2]) for Class IB, IC,
II and IIIA liquids.
where flammable liquids are stored. If
employee smoking is permitted in the facility,
designated areas are desirable, as well as the
Offices and Institutional Occupancies
provision of non-combustible ash trays or
Storage of flammable and combustible liquids
in offices, educational, institutional, daycare, and
other similar occupancies should be limited to
those materials and quantities necessary to
support daily operations. The maximum
combined volume of Class I and Class II liquids
stored outside of a flammable liquids cabinet
should not exceed 10 gal. (38 L). Storage of
Class IIIA liquids outside of a flammable liquids
cabinet or inside liquid storage areas should not
exceed 60 gal. (230 L).
receptacles. “No Smoking” signs should be
posted in all areas where smoking is
not permitted.
Measures should be taken to reduce the risk
of fire from the use of powered industrial
trucks in flammable liquid storage areas.
The types of powered industrial trucks
used should be suitable for the commodities
stored, as required by NFPA 505, Fire Safety
Standard for Powered Industrial Trucks
Including Type Designations, Areas of Use,
Fire Prevention
Conversions, Maintenance, and Operation.
Basic fire prevention goals in the storage of
The standard applies to forklift trucks, tractors,
flammable and combustible liquids are to
platform lift trucks, motorized hand trucks,
eliminate sources of ignition in areas where
and other specialized industrial trucks
materials are stored, reduce the amount of
powered by electric motors or internal
easily ignitable materials present near sources
combustion engines, and provide information
of ignition, and prevent contact of an ignition
on their safe use, maintenance, and operation
source with any flammable vapor/air mixture.
to minimize fire hazards.
Building services should meet local fire and
Hot-work operations, such as welding and
building code requirements. The electrical
cutting, in flammable liquid storage areas
system should comply with NFPA 70,
should comply with NFPA 51B, Standard for
National Electric Code. Equipment subject to
Fire Prevention During Welding, Cutting, and
static accumulation, such as racks, ventilating
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H A N OV E R R I S K S O LU T I O N S
Other Hot Work. A hot-work permit should
be issued and a person appointed with
responsibility for implementing a fire
prevention program. A fire watch should
be maintained during hot-work operations,
and for not less than 30 minutes following
References
1.Engineering and Safety Service. Static
Electricity. FP-70-08. Jersey City, NJ: ISO
Services, Inc., 2011.
2.—. Flammable and Combustible Liquids
completion of the operation. See Hot-Work
Storage Areas. FP-70-13. Jersey City, NJ:
Permit, on Hanover’s Risk Solutions website
ISO Services, Inc., 2014.
for additional information on this topic.
3.National Fire Protection Association
Lightning protection should be considered
(NFPA). Fire Protection Handbook. 20th
for outside storage areas in regions highly
ed. Quincy, MA: NFPA, 2008.
susceptible to lightning strikes. Lightning
protection should be installed in accordance
with NFPA 780, Standard for the Installation
of Lightning Protection Systems.
4.—. National Electrical Code. NFPA 70.
Quincy, MA: NFPA, 2014.
5.—. Standard for the Installation of Sprinkler
Systems. NFPA 13. Quincy, MA: NFPA,
2013.
6.—. Uniform Fire Code. NFPA 1. Quincy,
MA: NFPA, 2012.
c To learn more about Hanover Risk Solutions,
s
visit hanoverrisksolutions.com
The Hanover Insurance Company
440 Lincoln Street, Worcester, MA 01653
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Copyright ©2014, ISO Services, Inc.
The recommendation(s), advice and contents of this material are provided for informational purposes only and do not purport to address every possible legal obligation, hazard, code
violation, loss potential or exception to good practice. The Hanover Insurance Company and its affiliates and subsidiaries (“The Hanover”) specifically disclaim any warranty or representation
that acceptance of any recommendations or advice contained herein will make any premises, property or operation safe or in compliance with any law or regulation. Under no circumstances
should this material or your acceptance of any recommendations or advice contained herein be construed as establishing the existence or availability of any insurance coverage with
The Hanover. By providing this information to you, The Hanover does not assume (and specifically disclaims) any duty, undertaking or responsibility to you. The decision to accept or
implement any recommendation(s) or advice contained in this material must be made by you.
171-1741 (1/16)
LC 2015-351