[Code of Federal Regulations]
[Title 29, Volume 5]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 29CFR1910.106]
[Page 237-270]
TITLE 29--LABOR
CHAPTER XVII--OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT
OF LABOR
PART 1910_OCCUPATIONAL SAFETY AND HEALTH STANDARDS--Table of Contents
Subpart H_Hazardous Materials
Sec. 1910.106 Flammable and combustible liquids.
(a) Definitions. As used in this section:
(1) Aerosol shall mean a material which is dispensed from its
container as a mist, spray, or foam by a propellant under pressure.
(2) Atmospheric tank shall mean a storage tank which has been
designed to operate at pressures from atmospheric through 0.5 p.s.i.g.
(3) Automotive service station shall mean that portion of property
where flammable or combustible liquids used as motor fuels are stored
and dispensed from fixed equipment into the fuel tanks of motor vehicles
and shall include any facilities available for the sale and service of
tires, batteries, and accessories, and for minor automotive maintenance
work. Major automotive repairs, painting, body and fender work are
excluded.
(4) Basement shall mean a story of a building or structure having
one-half or more of its height below ground level and to which access
for fire fighting purposes is unduly restricted.
(5) Boiling point shall mean the boiling point of a liquid at a
pressure of 14.7 pounds per square inch absolute (p.s.i.a.) (760 mm.).
Where an accurate boiling point is unavailable for the material in
question, or for mixtures which do not have a constant boiling point,
for purposes of this section the 10 percent point of a distillation
performed in accordance with the Standard Method of Test for
Distillation of Petroleum Products, ASTM D-86-62, which is incorporated
by reference as specified in Sec. 1910.6, may be used as the boiling
point of the liquid.
(6) Boilover shall mean the expulsion of crude oil (or certain other
liquids) from a burning tank. The light fractions of the crude oil
burnoff producing a heat wave in the residue, which on reaching a water
strata may result in the expulsion of a portion of the contents of the
tank in the form of froth.
(7) Bulk plant shall mean that portion of a property where flammable
or combustible liquids are received by tank vessel, pipelines, tank car,
or tank vehicle, and are stored or blended in bulk for the purpose of
distributing such liquids by tank vessel, pipeline, tank car, tank
vehicle, or container.
(8) Chemical plant shall mean a large integrated plant or that
portion of such a plant other than a refinery or distillery where
flammable or combustible liquids are produced by chemical reactions or
used in chemical reactions.
(9) Closed container shall mean a container as herein defined, so
sealed by means of a lid or other device that neither liquid nor vapor
will escape from it at ordinary temperatures.
(10) Crude petroleum shall mean hydrocarbon mixtures that have a
flash point below 150 [deg]F. and which have not been processed in a
refinery.
(11) Distillery shall mean a plant or that portion of a plant where
flammable or combustible liquids produced by fermentation are
concentrated, and where the concentrated products may also be mixed,
stored, or packaged.
(12) 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 1 hour.
(13) Flammable aerosol shall mean an aerosol which is required to be
labeled ``Flammable'' under the Federal Hazardous Substances Labeling
Act (15 U.S.C. 1261). For the purposes of paragraph (d) of this section,
such aerosols are considered Class IA liquids.
(14) Flashpoint means the minimum temperature at which a liquid
gives off vapor within a test vessel in sufficient
[[Page 238]]
concentration to form an ignitable mixture with air near the surface of
the liquid, and shall be determined as follows:
(i) For a liquid which has a viscosity of less than 45 SUS at 100
[deg]F. (37.8 [deg]C.), does not contain suspended solids, and does not
have a tendency to form a surface film while under test, the procedure
specified in the Standard Method of Test for Flashpoint by Tag Closed
Tester (ASTM D-56-70), which is incorporated by reference as specified
in Sec. 1910.6, shall be used.
(ii) For a liquid which has a viscosity of 45 SUS or more at 100
[deg]F. (37.8 [deg]C.), or contains suspended solids, or has a tendency
to form a surface film while under test, the Standard Method of Test for
Flashpoint by Pensky-Martens Closed Tester (ASTM D-93-71) shall be used,
except that the methods specified in Note 1 to section 1.1 of ASTM D-93-
71 may be used for the respective materials specified in the Note. The
preceding ASTM standards are incorporated by reference as specified in
Sec. 1910.6.
(iii) For a liquid that is a mixture of compounds that have
different volatilities and flashpoints, its flashpoint shall be
determined by using the procedure specified in paragraph (a)(14) (i) or
(ii) of this section on the liquid in the form it is shipped. If the
flashpoint, as determined by this test, is 100 [deg]F. (37.8 [deg]C.) or
higher, an additional flashpoint determination shall be run on a sample
of the liquid evaporated to 90 percent of its original volume, and the
lower value of the two tests shall be considered the flashpoint of the
material.
(iv) Organic peroxides, which undergo autoaccelerating thermal
decomposition, are excluded from any of the flashpoint determination
methods specified in this subparagraph.
(15) Hotel shall mean buildings or groups of buildings under the
same management in which there are sleeping accommodations for hire,
primarily used by transients who are lodged with or without meals
including but not limited to inns, clubs, motels, and apartment hotels.
(16) Institutional occupancy shall mean the occupancy or use of a
building or structure or any portion thereof by persons harbored or
detained to receive medical, charitable or other care or treatment, or
by persons involuntarily detained.
(17) Liquid shall mean, for the purpose of this section, any
material which has a fluidity greater than that of 300 penetration
asphalt when tested in accordance with ASTM Test for Penetration for
Bituminous Materials, D-5-65, which is incorporated by reference as
specified in Sec. 1910.6. When not otherwise identified, the term
liquid shall include both flammable and combustible liquids.
(18) Combustible liquid means any liquid having a flashpoint at or
above 100 [deg]F. (37.8 [deg]C.) Combustible liquids shall be divided
into two classes as follows:
(i) Class II liquids shall include those with flashpoints at or
above 100 [deg]F. (37.8 [deg]C.) and below 140 [deg]F. (60 [deg]C.),
except any mixture having components with flashpoints of 200 [deg]F.
(93.3 [deg]C.) or higher, the volume of which make up 99 percent or more
of the total volume of the mixture.
(ii) Class III liquids shall include those with flashpoints at or
above 140 [deg]F. (60 [deg]C.) Class III liquids are subdivided into two
subclasses:
(a) Class IIIA liquids shall include those with flashpoints at or
above 140 [deg]F. (60 [deg]C.) and below 200 [deg]F. (93.3 [deg]C.),
except any mixture having components with flashpoints of 200 [deg]F.
(93.3 [deg]C.), or higher, the total volume of which make up 99 percent
or more of the total volume of the mixture.
(b) Class IIIB liquids shall include those with flashpoints at or
above 200 [deg]F. (93.3 [deg]C.). This section does not cover Class IIIB
liquids. Where the term ``Class III liquids is used in this section, it
shall mean only Class IIIA liquids.
(iii) When a combustible liquid is heated for use to within 30
[deg]F. (16.7 [deg]C.) of its flashpoint, it shall be handled in
accordance with the requirements for the next lower class of liquids.
(19) Flammable liquid means any liquid having a flashpoint below 100
[deg]F. (37.8 [deg]C.), except any mixture having components with
flashpoints of 100 [deg]F. (37.8 [deg]C.) or higher, the total of which
make up 99 percent or more of the total volume of the mixture. Flammable
liquids shall be known as Class I liquids.
[[Page 239]]
Class I liquids are divided into three classes as follows:
(i) Class IA shall include liquids having flashpoints below 73
[deg]F. (22.8 [deg]C.) and having a boiling point below 100 [deg]F.
(37.8 [deg]C.).
(ii) Class IB shall include liquids having flashpoints below 73
[deg]F. (22.8 [deg]C.) and having a boiling point at or above 100
[deg]F. (37.8 [deg]C.).
(iii) Class IC shall include liquids having flashpoints at or above
73 [deg]F. (22.8 [deg]C.) and below 100 [deg]F. (37.8 [deg]C.).
(20) Unstable (reactive) liquid shall mean a liquid which in the
pure state or as commercially produced or transported will vigorously
polymerize, decompose, condense, or will become self-reactive under
conditions of shocks, pressure, or temperature.
(21) Low-pressure tank shall mean a storage tank which has been
designed to operate at pressures above 0.5 p.s.i.g. but not more than 15
p.s.i.g.
(22) Marine service station shall mean that portion of a property
where flammable or combustible liquids used as fuels are stored and
dispensed from fixed equipment on shore, piers, wharves, or floating
docks into the fuel tanks of self-propelled craft, and shall include all
facilities used in connection therewith.
(23) Mercantile occupancy shall mean the occupancy or use of a
building or structure or any portion thereof for the displaying,
selling, or buying of goods, wares, or merchandise.
(24) Office occupancy shall mean the occupancy or use of a building
or structure or any portion thereof for the transaction of business, or
the rendering or receiving of professional services.
(25) Portable tank shall mean a closed container having a liquid
capacity over 60 U.S. gallons and not intended for fixed installation.
(26) Pressure vessel shall mean a storage tank or vessel which has
been designed to operate at pressures above 15 p.s.i.g.
(27) Protection for exposure shall mean adequate fire protection for
structures on property adjacent to tanks, where there are employees of
the establishment.
(28) Refinery shall mean a plant in which flammable or combustible
liquids are produced on a commercial scale from crude petroleum, natural
gasoline, or other hydrocarbon sources.
(29) Safety can shall mean 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 subjected to
fire exposure.
(30) Vapor pressure shall mean the pressure, measured in pounds per
square inch (absolute) exerted by a volatile liquid as determined by the
``Standard Method of Test for Vapor Pressure of Petroleum Products (Reid
Method),'' American Society for Testing and Materials ASTM D323-68,
which is incorporated by reference as specified in Sec. 1910.6.
(31) Ventilation as specified in this section is for the prevention
of fire and explosion. It is considered adequate if it is sufficient to
prevent accumulation of significant quantities of vapor-air mixtures in
concentration over one-fourth of the lower flammable limit.
(32) Storage: Flammable or combustible liquids shall be stored in a
tank or in a container that complies with paragraph (d)(2) of this
section.
(33) Barrel shall mean a volume of 42 U.S. gallons.
(34) Container shall mean any can, barrel, or drum.
(35) Approved unless otherwise indicated, approved, or listed by a
nationally recognized testing laboratory. Refer to Sec. 1910.7 for
definition of nationally recognized testing laboratory.
(36) Listed see ``approved'' in Sec. 1910.106(a)(35).
(37) SUS means Saybolt Universal Seconds as determined by the
Standard Method of Test for Saybolt Viscosity (ASTM D-88-56), and may be
determined by use of the SUS conversion tables specified in ASTM Method
D2161-66 following determination of viscosity in accordance with the
procedures specified in the Standard Method of Test for Viscosity of
Transparent and Opaque Liquids (ASTM D445-65).
(38) Viscous means a viscosity of 45 SUS or more.
(b) Tank storage--(1) Design and construction of tanks--(i)
Materials. (a) Tanks shall be built of steel except as provided in
paragraphs (b)(1)(i) (b) through (e) of this section.
[[Page 240]]
(b) Tanks may be built of materials other than steel for
installation underground or if required by the properties of the liquid
stored. Tanks located above ground or inside buildings shall be of
noncombustible construction.
(c) Tanks built of materials other than steel shall be designed to
specifications embodying principles recognized as good engineering
design for the material used.
(d) Unlined concrete tanks may be used for storing flammable or
combustible liquids having a gravity of 40[deg] API or heavier. Concrete
tanks with special lining may be used for other services provided the
design is in accordance with sound engineering practice.
(e) [Reserved]
(f) Special engineering consideration shall be required if the
specific gravity of the liquid to be stored exceeds that of water or if
the tanks are designed to contain flammable or combustible liquids at a
liquid temperature below 0 [deg]F.
(ii) Fabrication. (a) [Reserved]
(b) Metal tanks shall be welded, riveted, and caulked, brazed, or
bolted, or constructed by use of a combination of these methods. Filler
metal used in brazing shall be nonferrous metal or an alloy having a
melting point above 1000 [deg]F. and below that of the metal joined.
(iii) Atmospheric tanks. (a) Atmospheric tanks shall be built in
accordance with acceptable good standards of design. Atmospheric tanks
may be built in accordance with the following consensus standards that
are incorporated by reference as specified in Sec. 1910.6:
(1) Underwriters' Laboratories, Inc., Subjects No. 142, Standard for
Steel Aboveground Tanks for Flammable and Combustible Liquids, 1968; No.
58, Standard for Steel Underground Tanks for Flammable and Combustible
Liquids, Fifth Edition, December 1961; or No. 80, Standard for Steel
Inside Tanks for Oil-Burner Fuel, September 1963.
(2) American Petroleum Institute Standards No. 650, Welded Steel
Tanks for Oil Storage, Third Edition, 1966.
(3) American Petroleum Institute Standards No. 12B, Specification
for Bolted Production Tanks, Eleventh Edition, May 1958, and Supplement
1, March 1962; No. 12D, Specification for Large Welded Production Tanks,
Seventh Edition, August 1957; or No. 12F, Specification for Small Welded
Production Tanks, Fifth Edition, March 1961. Tanks built in accordance
with these standards shall be used only as production tanks for storage
of crude petroleum in oil-producing areas.
(b) Tanks designed for underground service not exceeding 2,500
gallons capacity may be used aboveground.
(c) Low-pressure tanks and pressure vessels may be used as
atmospheric tanks.
(d) Atmospheric tanks shall not be used for the storage of a
flammable or combustible liquid at a temperature at or above its boiling
point.
(iv) Low pressure tanks. (a) The normal operating pressure of the
tank shall not exceed the design pressure of the tank.
(b) Low-pressure tanks shall be built in accordance with acceptable
standards of design. Low-pressure tanks may be built in accordance with
the following consensus standards that are incorporated by reference as
specified in Sec. 1910.6:
(1) American Petroleum Institute Standard No. 620. Recommended Rules
for the Design and Construction of Large, Welded, Low-Pressure Storage
Tanks, Third Edition, 1966.
(2) The principles of the Code for Unfired Pressure Vessels, Section
VIII of the ASME Boiler and Pressure Vessels Code, 1968.
(c) Atmospheric tanks built according to Underwriters' Laboratories,
Inc., requirements in subdivision (iii)(a) of and shall be limited to
2.5 p.s.i.g. under emergency venting conditions.
This paragraph may be used for operating pressures not exceeding 1
p.s.i.g.
(d) Pressure vessels may be used as low-pressure tanks.
(v) Pressure vessels. (a) The normal operating pressure of the
vessel shall not exceed the design pressure of the vessel.
(b) Pressure vessels shall be built in accordance with the Code for
Unfired Pressure Vessels, Section VIII of the ASME Boiler and Pressure
Vessel Code 1968.
[[Page 241]]
(vi) Provisions for internal corrosion. When tanks are not designed
in accordance with the American Petroleum Institute, American Society of
Mechanical Engineers, or the Underwriters' Laboratories, Inc.'s,
standards, or if corrosion is anticipated beyond that provided for in
the design formulas used, additional metal thickness or suitable
protective coatings or linings shall be provided to compensate for the
corrosion loss expected during the design life of the tank.
(2) Installation of outside aboveground tanks.
(i) [Reserved]
(ii) Spacing (shell-to-shell) between aboveground tanks. (a) The
distance between any two flammable or combustible liquid storage tanks
shall not be less than 3 feet.
(b) Except as provided in paragraph (b)(2)(ii)(c) of this section,
the distance between any two adjacent tanks shall not be less than one-
sixth the sum of their diameters. When the diameter of one tank is less
than one-half the diameter of the adjacent tank, the distance between
the two tanks shall not be less than one-half the diameter of the
smaller tank.
(c) Where crude petroleum in conjunction with production facilities
are located in noncongested areas and have capacities not exceeding
126,000 gallons (3,000 barrels), the distance between such tanks shall
not be less than 3 feet.
(d) Where unstable flammable or combustible liquids are stored, the
distance between such tanks shall not be less than one-half the sum of
their diameters.
(e) When tanks are compacted in three or more rows or in an
irregular pattern, greater spacing or other means shall be provided so
that inside tanks are accessible for firefighting purposes.
(f) The minimum separation between a liquefied petroleum gas
container and a flammable or combustible liquid storage tank shall be 20
feet, except in the case of flammable or combustible liquid tanks
operating at pressures exceeding 2.5 p.s.i.g. or equipped with emergency
venting which will permit pressures to exceed 2.5 p.s.i.g. in which case
the provisions of subdivisions (a) and (b) of this subdivision shall
apply. Suitable means shall be taken to prevent the accumulation of
flammable or combustible liquids under adjacent liquefied petroleum gas
containers such as by diversion curbs or grading. When flammable or
combustible liquid storage tanks are within a diked area, the liquefied
petroleum gas containers shall be outside the diked area and at least 10
feet away from the centerline of the wall of the diked area. The
foregoing provisions shall not apply when liquefied petroleum gas
containers of 125 gallons or less capacity are installed adjacent to
fuel oil supply tanks of 550 gallons or less capacity.
(iii) [Reserved]
(iv) Normal venting for aboveground tanks. (a) Atmospheric storage
tanks shall be adequately vented to prevent the development of vacuum or
pressure sufficient to distort the roof of a cone roof tank or exceeding
the design pressure in the case of other atmospheric tanks, as a result
of filling or emptying, and atmospheric temperature changes.
(b) Normal vents shall be sized either in accordance with: (1) The
American Petroleum Institute Standard 2000 (1968), Venting Atmospheric
and Low-Pressure Storage Tanks, which is incorporated by reference as
specified in Sec. 1910.6; or (2) other accepted standard; or (3) shall
be at least as large as the filling or withdrawal connection, whichever
is larger but in no case less than 1\1/4\ inch nominal inside diameter.
(c) Low-pressure tanks and pressure vessels shall be adequately
vented to prevent development of pressure or vacuum, as a result of
filling or emptying and atmospheric temperature changes, from exceeding
the design pressure of the tank or vessel. Protection shall also be
provided to prevent overpressure from any pump discharging into the tank
or vessel when the pump discharge pressure can exceed the design
pressure of the tank or vessel.
(d) If any tank or pressure vessel has more than one fill or
withdrawal connection and simultaneous filling or withdrawal can be
made, the vent size shall be based on the maximum anticipated
simultaneous flow.
(e) Unless the vent is designed to limit the internal pressure 2.5
p.s.i. or
[[Page 242]]
less, the outlet of vents and vent drains shall be arranged to discharge
in such a manner as to prevent localized overheating of any part of the
tank in the event vapors from such vents are ignited.
(f) Tanks and pressure vessels storing Class IA liquids shall be
equipped with venting devices which shall be normally closed except when
venting to pressure or vacuum conditions. Tanks and pressure vessels
storing Class IB and IC liquids shall be equipped with venting devices
which shall be normally closed except when venting under pressure or
vacuum conditions, or with approved flame arresters.
Exemption: Tanks of 3,000 bbls. capacity or less containing crude
petroleum in crude-producing areas; and, outside aboveground atmospheric
tanks under 1,000 gallons capacity containing other than Class IA
flammable liquids may have open vents. (See subdivision (vi)(b) of this
subparagraph.)
(g) Flame arresters or venting devices required in subdivision (f)
of this subdivision may be omitted for Class IB and IC liquids where
conditions are such that their use may, in case of obstruction, result
in tank damage.
(v) Emergency relief venting for fire exposure for aboveground
tanks. (a) Every aboveground storage tank shall have some form of
construction or device that will relieve excessive internal pressure
caused by exposure fires.
(b) In a vertical tank the construction referred to in subdivision
(a) of this subdivision may take the form of a floating roof, lifter
roof, a weak roof-to-shell seam, or other approved pressure relieving
construction. The weak roof-to-shell seam shall be constructed to fail
preferential to any other seam.
(c) Where entire dependence for emergency relief is placed upon
pressure relieving devices, the total venting capacity of both normal
and emergency vents shall be enough to prevent rupture of the shell or
bottom of the tank if vertical, or of the shell or heads if horizontal.
If unstable liquids are stored, the effects of heat or gas resulting
from polymerization, decomposition, condensation, or self-reactivity
shall be taken into account. The total capacity of both normal and
emergency venting devices shall be not less than that derived from Table
H-10 except as provided in subdivision (e) or (f) of this subdivision.
Such device may be a self-closing manhole cover, or one using long bolts
that permit the cover to lift under internal pressure, or an additional
or larger relief valve or valves. The wetted area of the tank shall be
calculated on the basis of 55 percent of the total exposed area of a
sphere or spheroid, 75 percent of the total exposed area of a horizontal
tank and the first 30 feet above grade of the exposed shell area of a
vertical tank.
Table H-10--Wetted Area Versus Cubic Feet Free Air Per Hour
[14.7 psia and 60 [deg]F.]
------------------------------------------------------------------------
Square Square
Square feet CFH feet CFH feet CFH
------------------------------------------------------------------------
20 21,100 200 211,000 1,000 524,000
30 31,600 250 239,000 1,200 557,000
40 42,100 300 265,000 1,400 587,000
50 52,700 350 288,000 1,600 614,000
60 63,200 400 312,000 1,800 639,000
70 73,700 500 354,000 2,000 662,000
80 84,200 600 392,000 2,400 704,000
90 94,800 700 428,000 2,800 742,000
100 105,000 800 462,000 and
120 126,000 900 493,000 over
140 147,000 1,000 524,000
160 168,000
180 190,000
200 211,000
------------------------------------------------------------------------
(d) For tanks and storage vessels designed for pressure over 1
p.s.i.g., the total rate of venting shall be determined in accordance
with Table H-10, except that when the exposed wetted area of the surface
is greater than 2,800 square feet, the total rate of venting
[[Page 243]]
shall be calculated by the following formula:
CFH = 1,107A \0.82\
Where;
CFH = Venting requirement, in cubic feet of free air per hour.
A = Exposed wetted surface, in square feet.
Note: The foregoing formula is based on Q=21,000A\0.82\.
(e) The total emergency relief venting capacity for any specific
stable liquid may be determined by the following formula:
V = 1337 / L[radic]M
V = Cubic feet of free air per hour from Table H-10.
L = Latent heat of vaporization of specific liquid in B.t.u. per pound.
M = Molecular weight of specific liquids.
(f) The required airflow rate of subdivision (c) or (e) of this
subdivision may be multiplied by the appropriate factor listed in the
following schedule when protection is provided as indicated. Only one
factor may be used for any one tank.
0.5 for drainage in accordance with subdivision (vii)(b) of this
subparagraph for tanks over 200 square feet of wetted area.
0.3 for approved water spray.
0.3 for approved insulation.
0.15 for approved water spray with approved insulation.
(g) The outlet of all vents and vent drains on tanks equipped with
emergency venting to permit pressures exceeding 2.5 p.s.i.g. shall be
arranged to discharge in such a way as to prevent localized overheating
of any part of the tank, in the event vapors from such vents are
ignited.
(h) Each commercial tank venting device shall have stamped on it the
opening pressure, the pressure at which the valve reaches the full open
position, and the flow capacity at the latter pressure, expressed in
cubic feet per hour of air at 60 [deg]F. and at a pressure of 14.7
p.s.i.a.
(i) The flow capacity of tank venting devices 12 inches and smaller
in nominal pipe size shall be determined by actual test of each type and
size of vent. These flow tests may be conducted by the manufacturer if
certified by a qualified impartial observer, or may be conducted by an
outside agency. The flow capacity of tank venting devices larger than 12
inches nominal pipe size, including manhole covers with long bolts or
equivalent, may be calculated provided that the opening pressure is
actually measured, the rating pressure and corresponding free orifice
area are stated, the word ``calculated'' appears on the nameplate, and
the computation is based on a flow coefficient of 0.5 applied to the
rated orifice area.
(vi) Vent piping for aboveground tanks. (a) Vent piping shall be
constructed in accordance with paragraph (c) of this section.
(b) Where vent pipe outlets for tanks storing Class I liquids are
adjacent to buildings or public ways, they shall be located so that the
vapors are released at a safe point outside of buildings and not less
than 12 feet above the adjacent ground level. In order to aid their
dispersion, vapors shall be discharged upward or horizontally away from
closely adjacent walls. Vent outlets shall be located so that flammable
vapors will not be trapped by eaves or other obstructions and shall be
at least five feet from building openings.
(c) When tank vent piping is manifolded, pipe sizes shall be such as
to discharge, within the pressure limitations of the system, the vapors
they may be required to handle when manifolded tanks are subject to the
same fire exposure.
(vii) Drainage, dikes, and walls for aboveground tanks--(a) Drainage
and diked areas. The area surrounding a tank or a group of tanks shall
be provided with drainage as in subdivision (b) of this subdivision, or
shall be diked as provided in subdivision (c) of this subdivision, to
prevent accidental discharge of liquid from endangering adjoining
property or reaching waterways.
(b) Drainage. Where protection of adjoining property or waterways is
by means of a natural or manmade drainage system, such systems shall
comply with the following:
(1) [Reserved]
(2) The drainage system shall terminate in vacant land or other area
or in an impounding basin having a capacity not smaller than that of the
largest tank served. This termination area and the route of the drainage
system shall
[[Page 244]]
be so located that, if the flammable or combustible liquids in the
drainage system are ignited, the fire will not seriously expose tanks or
adjoining property.
(c) Diked areas. Where protection of adjoining property or waterways
is accomplished by retaining the liquid around the tank by means of a
dike, the volume of the diked area shall comply with the following
requirements:
(1) Except as provided in subdivision (2) of this subdivision, the
volumetric capacity of the diked area shall not be less than the
greatest amount of liquid that can be released from the largest tank
within the diked area, assuming a full tank. The capacity of the diked
area enclosing more than one tank shall be calculated by deducting the
volume of the tanks other than the largest tank below the height of the
dike.
(2) For a tank or group of tanks with fixed roofs containing crude
petroleum with boilover characteristics, the volumetric capacity of the
diked area shall be not less than the capacity of the largest tank
served by the enclosure, assuming a full tank. The capacity of the diked
enclosure shall be calculated by deducting the volume below the height
of the dike of all tanks within the enclosure.
(3) Walls of the diked area shall be of earth, steel, concrete or
solid masonry designed to be liquidtight and to withstand a full
hydrostatic head. Earthen walls 3 feet or more in height shall have a
flat section at the top not less than 2 feet wide. The slope of an
earthen wall shall be consistent with the angle of repose of the
material of which the wall is constructed.
(4) The walls of the diked area shall be restricted to an average
height of 6 feet above interior grade.
(5) [Reserved]
(6) No loose combustible material, empty or full drum or barrel,
shall be permitted within the diked area.
(viii) Tank openings other than vents for aboveground tanks.
(a)-(c) [Reserved]
(d) Openings for gaging shall be provided with a vaportight cap or
cover.
(e) For Class IB and Class IC liquids other than crude oils,
gasolines, and asphalts, the fill pipe shall be so designed and
installed as to minimize the possibility of generating static
electricity. A fill pipe entering the top of a tank shall terminate
within 6 inches of the bottom of the tank and shall be installed to
avoid excessive vibration.
(f) Filling and emptying connections which are made and broken shall
be located outside of buildings at a location free from any source of
ignition and not less than 5 feet away from any building opening. Such
connection shall be closed and liquidtight when not in use. The
connection shall be properly identified.
(3) Installation of underground tanks--(i) Location. Excavation for
underground storage tanks shall be made with due care to avoid
undermining of foundations of existing structures. Underground tanks or
tanks under buildings shall be so located with respect to existing
building foundations and supports that the loads carried by the latter
cannot be transmitted to the tank. The distance from any part of a tank
storing Class I liquids to the nearest wall of any basement or pit shall
be not less than 1 foot, and to any property line that may be built
upon, not less than 3 feet. The distance from any part of a tank storing
Class II or Class III liquids to the nearest wall of any basement, pit
or property line shall be not less than 1 foot.
(ii) Depth and cover. Underground tanks shall be set on firm
foundations and surrounded with at least 6 inches of noncorrosive, inert
materials such as clean sand, earth, or gravel well tamped in place. The
tank shall be placed in the hole with care since dropping or rolling the
tank into the hole can break a weld, puncture or damage the tank, or
scrape off the protective coating of coated tanks. Tanks shall be
covered with a minimum of 2 feet of earth, or shall be covered with not
less than 1 foot of earth, on top of which shall be placed a slab of
reinforced concrete not less than 4 inches thick. When underground tanks
are, or are likely to be, subject to traffic, they shall be protected
against damage from vehicles passing over them by at least 3 feet of
earth cover, or 18 inches of
[[Page 245]]
well-tamped earth, plus 6 inches of reinforced concrete or 8 inches of
asphaltic concrete. When asphaltic or reinforced concrete paving is used
as part of the protection, it shall extend at least 1 foot horizontally
beyond the outline of the tank in all directions.
(iii) Corrosion protection. Corrosion protection for the tank and
its piping shall be provided by one or more of the following methods:
(a) Use of protective coatings or wrappings;
(b) Cathodic protection; or,
(c) Corrosion resistant materials of construction.
(iv) Vents. (a) Location and arrangement of vents for Class I
liquids. Vent pipes from tanks storing Class I liquids shall be so
located that the discharge point is outside of buildings, higher than
the fill pipe opening, and not less than 12 feet above the adjacent
ground level. Vent pipes shall discharge only upward in order to
disperse vapors. Vent pipes 2 inches or less in nominal inside diameter
shall not be obstructed by devices that will cause excessive back
pressure. Vent pipe outlets shall be so located that flammable vapors
will not enter building openings, or be trapped under eaves or other
obstructions. If the vent pipe is less than 10 feet in length, or
greater than 2 inches in nominal inside diameter, the outlet shall be
provided with a vacuum and pressure relief device or there shall be an
approved flame arrester located in the vent line at the outlet or within
the approved distance from the outlet.
(b) Size of vents. Each tank shall be vented through piping adequate
in size to prevent blow-back of vapor or liquid at the fill opening
while the tank is being filled. Vent pipes shall be not less than 1\1/4\
inch nominal inside diameter.
Table H-11--Vent Line Diameters
------------------------------------------------------------------------
Pipe length \1\
Maximum flow GPM -----------------------------
50 feet 100 feet 200 feet
------------------------------------------------------------------------
Inches Inches Inches
100....................................... 1\1/4\ 1\1/4\ 1\1/4\
200....................................... 1\1/4\ 1\1/4\ 1\1/4\
300....................................... 1\1/4\ 1\1/4\ 1\1/2\
400....................................... 1\1/4\ 1\1/2\ 2
500....................................... 1\1/2\ 1\1/2\ 2
600....................................... 1\1/2\ 2 2
700....................................... 2 2 2
800....................................... 2 2 3
900....................................... 2 2 3
1,000..................................... 2 2 3
------------------------------------------------------------------------
\1\ Vent lines of 50 ft., 100 ft., and 200 ft. of pipe plus 7 ells.
(c) Location and arrangement of vents for Class II or Class III
liquids. Vent pipes from tanks storing Class II or Class III flammable
liquids shall terminate outside of the building and higher than the fill
pipe opening. Vent outlets shall be above normal snow level. They may be
fitted with return bends, coarse screens or other devices to minimize
ingress of foreign material.
(d) Vent piping shall be constructed in accordance with paragraph
(c) of this section. Vent pipes shall be so laid as to drain toward the
tank without sags or traps in which liquid can collect. They shall be
located so that they will not be subjected to physical damage. The tank
end of the vent pipe shall enter the tank through the top.
(e) When tank vent piping is manifolded, pipe sizes shall be such as
to discharge, within the pressure limitations of the system, the vapors
they may be required to handle when manifolded tanks are filled
simultaneously.
(v) Tank openings other than vents. (a) Connections for all tank
openings shall be vapor or liquid tight.
(b) Openings for manual gaging, if independent of the fill pipe,
shall be provided with a liquid-tight cap or cover. If inside a
building, each such opening shall be protected against liquid overflow
and possible vapor release by means of a spring loaded check valve or
other approved device.
(c) Fill and discharge lines shall enter tanks only through the top.
Fill lines shall be sloped toward the tank.
(d) For Class IB and Class IC liquids other than crude oils,
gasolines, and asphalts, the fill pipe shall be so designed and
installed as to minimize the possibility of generating static
electricity by terminating within 6 inches of the bottom of the tank.
(e) Filling and emptying connections which are made and broken shall
be located outside of buildings at a location
[[Page 246]]
free from any source of ignition and not less than 5 feet away from any
building opening. Such connection shall be closed and liquidtight when
not in use. The connection shall be properly identified.
(4) Installation of tanks inside of buildings--(i) Location. Tanks
shall not be permitted inside of buildings except as provided in
paragraphs (e), (g), (h), or (i) of this section.
(ii) Vents. Vents for tanks inside of buildings shall be as provided
in subparagraphs (2) (iv), (v), (vi)(b), and (3)(iv) of this paragraph,
except that emergency venting by the use of weak roof seams on tanks
shall not be permitted. Vents shall discharge vapors outside the
buildings.
(iii) Vent piping. Vent piping shall be constructed in accordance
with paragraph (c) of this section.
(iv) Tank openings other than vents. (a) Connections for all tank
openings shall be vapor or liquidtight. Vents are covered in subdivision
(ii) of this subparagraph.
(b) Each connection to a tank inside of buildings through which
liquid can normally flow shall be provided with an internal or an
external valve located as close as practical to the shell of the tank.
Such valves, when external, and their connections to the tank shall be
of steel except when the chemical characteristics of the liquid stored
are incompatible with steel. When materials other than steel are
necessary, they shall be suitable for the pressures, structural
stresses, and temperatures involved, including fire exposures.
(c) Flammable or combustible liquid tanks located inside of
buildings, except in one-story buildings designed and protected for
flammable or combustible liquid storage, shall be provided with an
automatic-closing heat-actuated valve on each withdrawal connection
below the liquid level, except for connections used for emergency
disposal, to prevent continued flow in the event of fire in the vicinity
of the tank. This function may be incorporated in the valve required in
(b) of this subdivision, and if a separate valve, shall be located
adjacent to the valve required in (b) of this subdivision.
(d) Openings for manual gaging, if independent of the fill pipe (see
(f) of this subdivision), shall be provided with a vaportight cap or
cover. Each such opening shall be protected against liquid overflow and
possible vapor release by means of a spring loaded check valve or other
approved device.
(e) For Class IB and Class IC liquids other than crude oils,
gasolines, and asphalts, the fill pipe shall be so designed and
installed as to minimize the possibility of generating static
electricity by terminating within 6 inches of the bottom of the tank.
(f) The fill pipe inside of the tank shall be installed to avoid
excessive vibration of the pipe.
(g) The inlet of the fill pipe shall be located outside of buildings
at a location free from any source of ignition and not less than 5 feet
away from any building opening. The inlet of the fill pipe shall be
closed and liquidtight when not in use. The fill connection shall be
properly identified.
(h) Tanks inside buildings shall be equipped with a device, or other
means shall be provided, to prevent overflow into the building.
(5) Supports, foundations, and anchorage for all tank locations--(i)
General. Tank supports shall be installed on firm foundations. Tank
supports shall be of concrete, masonry, or protected steel. Single wood
timber supports (not cribbing) laid horizontally may be used for outside
aboveground tanks if not more than 12 inches high at their lowest point.
(ii) Fire resistance. Steel supports or exposed piling shall be
protected by materials having a fire resistance rating of not less than
2 hours, except that steel saddles need not be protected if less than 12
inches high at their lowest point. Water spray protection or its
equivalent may be used in lieu of fire-resistive materials to protect
supports.
(iii) Spheres. The design of the supporting structure for tanks such
as spheres shall receive special engineering consideration.
(iv) Load distribution. Every tank shall be so supported as to
prevent the excessive concentration of loads on the supporting portion
of the shell.
(v) Foundations. Tanks shall rest on the ground or on foundations
made of concrete, masonry, piling, or steel. Tank foundations shall be
designed to
[[Page 247]]
minimize the possibility of uneven settling of the tank and to minimize
corrosion in any part of the tank resting on the foundation.
(vi) Flood areas. Where a tank is located in an area that may be
subjected to flooding, the applicable precautions outlined in this
subdivision shall be observed.
(a) No aboveground vertical storage tank containing a flammable or
combustible liquid shall be located so that the allowable liquid level
within the tank is below the established maximum flood stage, unless the
tank is provided with a guiding structure such as described in (m), (n),
and (o) of this subdivision.
(b) Independent water supply facilities shall be provided at
locations where there is no ample and dependable public water supply
available for loading partially empty tanks with water.
(c) In addition to the preceding requirements, each tank so located
that more than 70 percent, but less than 100 percent, of its allowable
liquid storage capacity will be submerged at the established maximum
flood stage, shall be safeguarded by one of the following methods: Tank
shall be raised, or its height shall be increased, until its top extends
above the maximum flood stage a distance equivalent to 30 percent or
more of its allowable liquid storage capacity: Provided, however, That
the submerged part of the tank shall not exceed two and one-half times
the diameter. Or, as an alternative to the foregoing, adequate
noncombustible structural guides, designed to permit the tank to float
vertically without loss of product, shall be provided.
(d) Each horizontal tank so located that more than 70 percent of its
storage capacity will be submerged at the established flood stage, shall
be anchored, attached to a foundation of concrete or of steel and
concrete, of sufficient weight to provide adequate load for the tank
when filled with flammable or combustible liquid and submerged by flood
waters to the established flood stage, or adequately secured by other
means.
(e) [Reserved]
(f) At locations where there is no ample and dependable water
supply, or where filling of underground tanks with liquids is
impracticable because of the character of their contents, their use, or
for other reasons, each tank shall be safeguarded against movement when
empty and submerged by high ground water or flood waters by anchoring,
weighting with concrete or other approved solid loading material, or
securing by other means. Each such tank shall be so constructed and
installed that it will safely resist external pressures due to high
ground water or flood waters.
(g) At locations where there is an ample and dependable water supply
available, underground tanks containing flammable or combustible
liquids, so installed that more than 70 percent of their storage
capacity will be submerged at the maximum flood stage, shall be so
anchored, weighted, or secured by other means, as to prevent movement of
such tanks when filled with flammable or combustible liquids, and
submerged by flood waters to the established flood stage.
(h) Pipe connections below the allowable liquid level in a tank
shall be provided with valves or cocks located as closely as practicable
to the tank shell. Such valves and their connections to tanks shall be
of steel or other material suitable for use with the liquid being
stored. Cast iron shall not be permitted.
(i) At locations where an independent water supply is required, it
shall be entirely independent of public power and water supply.
Independent source of water shall be available when flood waters reach a
level not less than 10 feet below the bottom of the lowest tank on a
property.
(j) The self-contained power and pumping unit shall be so located or
so designed that pumping into tanks may be carried on continuously
throughout the rise in flood waters from a level 10 feet below the
lowest tank to the level of the potential flood stage.
(k) Capacity of the pumping unit shall be such that the rate of rise
of water in all tanks shall be equivalent to the established potential
average rate of rise of flood waters at any stage.
(l) Each independent pumping unit shall be tested periodically to
insure
[[Page 248]]
that it is in satisfactory operating condition.
(m) Structural guides for holding floating tanks above their
foundations shall be so designed that there will be no resistance to the
free rise of a tank, and shall be constructed of noncombustible
material.
(n) The strength of the structure shall be adequate to resist
lateral movement of a tank subject to a horizontal force in any
direction equivalent to not less than 25 pounds per square foot acting
on the projected vertical cross-sectional area of the tank.
(o) Where tanks are situated on exposed points or bends in a
shoreline where swift currents in flood waters will be present, the
structures shall be designed to withstand a unit force of not less than
50 pounds per square foot.
(p) The filling of a tank to be protected by water loading shall be
started as soon as flood waters reach a dangerous flood stage. The rate
of filling shall be at least equal to the rate of rise of the
floodwaters (or the established average potential rate of rise).
(q) Sufficient fuel to operate the water pumps shall be available at
all times to insure adequate power to fill all tankage with water.
(r) All valves on connecting pipelines shall be closed and locked in
closed position when water loading has been completed.
(s) Where structural guides are provided for the protection of
floating tanks, all rigid connections between tanks and pipelines shall
be disconnected and blanked off or blinded before the floodwaters reach
the bottom of the tank, unless control valves and their connections to
the tank are of a type designed to prevent breakage between the valve
and the tank shell.
(t) All valves attached to tanks other than those used in connection
with water loading operations shall be closed and locked.
(u) If a tank is equipped with a swing line, the swing pipe shall be
raised to and secured at its highest position.
(v) Inspections. The Assistant Secretary or his designated
representative shall make periodic inspections of all plants where the
storage of flammable or combustible liquids is such as to require
compliance with the foregoing requirements, in order to assure the
following:
(1) That all flammable or combustible liquid storage tanks are in
compliance with these requirements and so maintained.
(2) That detailed printed instructions of what to do in flood
emergencies are properly posted.
(3) That station operators and other employees depended upon to
carry out such instructions are thoroughly informed as to the location
and operation of such valves and other equipment necessary to effect
these requirements.
(vii) Earthquake areas. In areas subject to earthquakes, the tank
supports and connections shall be designed to resist damage as a result
of such shocks.
(6) Sources of ignition. In locations where flammable vapors may be
present, precautions shall be taken to prevent ignition by eliminating
or controlling sources of ignition. Sources of ignition may include open
flames, lightning, smoking, cutting and welding, hot surfaces,
frictional heat, sparks (static, electrical, and mechanical),
spontaneous ignition, chemical and physical-chemical reactions, and
radiant heat.
(7) Testing--(i) General. All tanks, whether shop built or field
erected, shall be strength tested before they are placed in service in
accordance with the applicable paragraphs of the code under which they
were built. The American Society of Mechanical Engineers (ASME) code
stamp, American Petroleum Institute (API) monogram, or the label of the
Underwriters' Laboratories, Inc., on a tank shall be evidence of
compliance with this strength test. Tanks not marked in accordance with
the above codes shall be strength tested before they are placed in
service in accordance with good engineering principles and reference
shall be made to the sections on testing in the codes listed in
subparagraphs (1) (iii)(a), (iv)(b), or (v)(b) of this paragraph.
(ii) Strength. When the vertical length of the fill and vent pipes
is such that when filled with liquid the static head imposed upon the
bottom of the tank exceeds 10 pounds per square inch, the tank and
related piping shall be
[[Page 249]]
tested hydrostatically to a pressure equal to the static head thus
imposed.
(iii) Tightness. In addition to the strength test called for in
subdivisions (i) and (ii) of this subparagraph, all tanks and
connections shall be tested for tightness. Except for underground tanks,
this tightness test shall be made at operating pressure with air, inert
gas, or water prior to placing the tank in service. In the case of
field-erected tanks the strength test may be considered to be the test
for tank tightness. Underground tanks and piping, before being covered,
enclosed, or placed in use, shall be tested for tightness
hydrostatically, or with air pressure at not less than 3 pounds per
square inch and not more than 5 pounds per square inch.
(iv) Repairs. All leaks or deformations shall be corrected in an
acceptable manner before the tank is placed in service. Mechanical
caulking is not permitted for correcting leaks in welded tanks except
pinhole leaks in the roof.
(v) Derated operations. Tanks to be operated at pressures below
their design pressure may be tested by the applicable provisions of
subdivision (i) or (ii) of this subparagraph, based upon the pressure
developed under full emergency venting of the tank.
(c) Piping, valves, and fittings--(1) General--(i) Design. The
design (including selection of materials) fabrication, assembly, test,
and inspection of piping systems containing flammable or combustible
liquids shall be suitable for the expected working pressures and
structural stresses. Conformity with the applicable provisions of
Pressure Piping, ANSI B31 series and the provisions of this paragraph,
shall be considered prima facie evidence of compliance with the
foregoing provisions.
(ii) Exceptions. This paragraph does not apply to any of the
following:
(a) Tubing or casing on any oil or gas wells and any piping
connected directly thereto.
(b) Motor vehicle, aircraft, boat, or portable or stationary
engines.
(c) Piping within the scope of any applicable boiler and pressures
vessel code.
(iii) Definitions. As used in this paragraph, piping systems consist
of pipe, tubing, flanges, bolting, gaskets, valves, fittings, the
pressure containing parts of other components such as expansion joints
and strainers, and devices which serve such purposes as mixing,
separating, snubbing, distributing, metering, or controlling flow.
(2) Materials for piping, valves, and fittings--(i) Required
materials. Materials for piping, valves, or fittings shall be steel,
nodular iron, or malleable iron, except as provided in paragraph (c)(2)
(ii), (iii) and (iv) of this section.
(ii) Exceptions. Materials other than steel, nodular iron, or
malleable iron may be used underground, or if required by the properties
of the flammable or combustible liquid handled. Material other than
steel, nodular iron, or malleable iron shall be designed to
specifications embodying principles recognized as good engineering
practices for the material used.
(iii) Linings. Piping, valves, and fittings may have combustible or
noncombustible linings.
(iv) Low-melting materials. When low-melting point materials such as
aluminum and brass or materials that soften on fire exposure such as
plastics, or non-ductile materials such as cast iron, are necessary,
special consideration shall be given to their behavior on fire exposure.
If such materials are used in above ground piping systems or inside
buildings, they shall be suitably protected against fire exposure or so
located that any spill resulting from the failure of these materials
could not unduly expose persons, important buildings or structures or
can be readily controlled by remote valves.
(3) Pipe joints. Joints shall be made liquid tight. Welded or
screwed joints or approved connectors shall be used. Threaded joints and
connections shall be made up tight with a suitable lubricant or piping
compound. Pipe joints dependent upon the friction characteristics of
combustible materials for mechanical continuity of piping shall not be
used inside buildings. They may be used outside of buildings above or
below ground. If used above ground, the piping shall either be secured
to prevent disengagement at the fitting or the piping system shall be so
designed that any spill resulting from such disengagement could not
unduly expose
[[Page 250]]
persons, important buildings or structures, and could be readily
controlled by remote valves.
(4) Supports. Piping systems shall be substantially supported and
protected against physical damage and excessive stresses arising from
settlement, vibration, expansion, or contraction.
(5) Protection against corrosion. All piping for flammable or
combustible liquids, both aboveground and underground, where subject to
external corrosion, shall be painted or otherwise protected.
(6) Valves. Piping systems shall contain a sufficient number of
valves to operate the system properly and to protect the plant. Piping
systems in connection with pumps shall contain a sufficient number of
valves to control properly the flow of liquid in normal operation and in
the event of physical damage. Each connection to pipelines, by which
equipments such as tankcars or tank vehicles discharge liquids by means
of pumps into storage tanks, shall be provided with a check valve for
automatic protection against backflow if the piping arrangement is such
that backflow from the system is possible.
(7) Testing. All piping before being covered, enclosed, or placed in
use shall be hydrostatically tested to 150 percent of the maximum
anticipated pressure of the system, or pneumatically tested to 110
percent of the maximum anticipated pressure of the system, but not less
than 5 pounds per square inch gage at the highest point of the system.
This test shall be maintained for a sufficient time to complete visual
inspection of all joints and connections, but for at least 10 minutes.
(d) Container and portable tank storage--(1) Scope--(i) General.
This paragraph shall apply only to the storage of flammable or
combustible 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.
(ii) Exceptions. This paragraph shall not apply to the following:
(a) Storage of containers in bulk plants, service stations,
refineries, chemical plants, and distilleries;
(b) Class I or Class II liquids in the fuel tanks of a motor
vehicle, aircraft, boat, or portable or stationary engine;
(c) Flammable or combustible paints, oils, varnishes, and similar
mixtures used for painting or maintenance when not kept for a period in
excess of 30 days;
(d) Beverages when packaged in individual containers not exceeding 1
gallon in size.
(2) Design, construction, and capacity of containers--(i) General.
Only approved containers and portable tanks shall be used. Metal
containers and portable tanks meeting the requirements of and containing
products authorized by chapter I, title 49 of the Code of Federal
Regulations (regulations issued by the Hazardous Materials Regulations
Board, Department of Transportation), shall be deemed to be acceptable.
(ii) Emergency venting. 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 to 10 p.s.i.g., or 30 percent of the bursting pressure of the
tank, whichever is greater. The total venting capacity shall be not less
than that specified in paragraphs (b)(2)(v) (c) or (e) of this section.
At least one pressure-activated vent having a minimum capacity of 6,000
cubic feet of free air (14.7 p.s.i.a. and 60 [deg]F.) shall be used. It
shall be set to open at not less than 5 p.s.i.g. If fusible vents are
used, they shall be actuated by elements that operate at a temperature
not exceeding 300 [deg]F.
(iii) Size. Flammable and combustible liquid containers shall be in
accordance with Table H-12, except that glass or plastic containers of
no more than 1-gallon capacity may be used for a Class IA or IB
flammable liquid if:
(a)(1) Such liquid either would be rendered unfit for its intended
use by contact with metal or would excessively corrode a metal container
so as to create a leakage hazard; and
(2) The user's process either would require more than 1 pint of a
Class IA liquid or more than 1 quart of a Class IB liquid of a single
assay lot to be used at one time, or would require the maintenance of an
analytical standard liquid
[[Page 251]]
of a quality which is not met by the specified standards of liquids
available, and the quantity of the analytical standard liquid required
to be used in any one control process exceeds one-sixteenth the capacity
of the container allowed under Table H-12 for the class of liquid; or
(b) The containers are intended for direct export outside the United
States.
Table H-12--Maximum Allowable Size of Containers and Portable Tanks
----------------------------------------------------------------------------------------------------------------
Flammable liquids Combustible liquids
Container type -----------------------------------------------------------
Class IA Class IB Class IC Class II Class III
----------------------------------------------------------------------------------------------------------------
Glass or approved plastic........................... 1 pt 1 qt 1 gal 1 gal 1 gal.
Metal (other than DOT drums)........................ 1 gal 5 gal 5 gal 5 gal 5 gal.
Safety cans......................................... 2 gal 5 gal 5 gal 5 gal 5 gal.
Metal drums (DOT specifications).................... 60 gal 60 gal 60 gal 60 gal 60 gal.
Approved portable tanks............................. 660 gal 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 Sec.
1910.106(d)(2) (i) and (ii).
(3) Design, construction, and capacity of storage cabinets--(i)
Maximum capacity. Not more than 60 gallons of Class I or Class II
liquids, nor more than 120 gallons of Class III liquids may be stored in
a storage cabinet.
(ii) Fire resistance. Storage cabinets shall be designed and
constructed to limit the internal temperature to not more than 325
[deg]F. when subjected to a 10-minute fire test using the standard time-
temperature curve as set forth in Standard Methods of Fire Tests of
Building Construction and Materials, NFPA 251-1969, which is
incorporated by reference as specified in Sec. 1910.6. All joints and
seams shall remain tight and the door shall remain securely closed
during the fire test. Cabinets shall be labeled in conspicuous
lettering, ``Flammable--Keep Fire Away.''
(a) Metal cabinets constructed in the following manner shall be
deemed to be in compliance. The bottom, top, door, and sides of cabinet
shall be at least No. 18 gage sheet iron and double walled with 1\1/2\-
inch air space. Joints shall be riveted, welded or made tight by some
equally effective means. 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.
(b) Wooden cabinets constructed in the following manner shall be
deemed in compliance. The bottom, sides, and top shall be constructed of
an approved grade of plywood at least 1 inch in thickness, which shall
not break down or delaminate under fire conditions. All joints shall be
rabbetted and shall be fastened in two directions with flathead
woodscrews. When more than one door is used, there shall be a rabbetted
overlap of not less than 1 inch. Hinges shall be mounted in such a
manner as not to lose their holding capacity due to loosening or burning
out of the screws when subjected to the fire test.
(4) Design and construction of inside storage rooms--(i)
Construction. Inside storage rooms shall be constructed to meet the
required fire-resistive rating for their use. Such construction shall
comply with the test specifications set forth in Standard Methods of
Fire Tests of Building Construction and Materials, NFPA 251-1969. Where
an automatic sprinkler system is provided, the system shall be designed
and installed in an acceptable manner. Openings to other rooms or
buildings shall be provided with noncombustible 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. Openings
shall be provided with approved self-closing fire doors. The room shall
be liquid-tight where the walls join the floor. A permissible alternate
to the sill or ramp is an open-grated trench inside of the room which
drains to a safe location. Where other portions of the building or other
properties are exposed, windows shall be protected as set forth in the
Standard for Fire Doors and Windows, NFPA No. 80-1968, which is
incorporated by reference as specified in Sec. 1910.6, for Class E or F
openings. Wood
[[Page 252]]
at least 1 inch nominal thickness may be used for shelving, racks,
dunnage, scuffboards, floor overlay, and similar installations.
(ii) Rating and capacity. Storage in inside storage rooms shall
comply with Table H-13.
Table H-13--Storage in Inside Rooms
----------------------------------------------------------------------------------------------------------------
Total
allowable
quantities
Fire protection \1\ provided Fire resistance Maximum size (gals./sq.
ft./floor
area)
----------------------------------------------------------------------------------------------------------------
Yes...................................... 2 hours..................... 500 sq. ft................. 10
No....................................... 2 hours..................... 500 sq. ft................. 5
Yes...................................... 1 hour...................... 150 sq. ft................. 4
No....................................... 1 hour...................... 150 sq. ft................. 2
----------------------------------------------------------------------------------------------------------------
\1\ Fire protection system shall be sprinkler, water spray, carbon dioxide, or other system.
(iii) Wiring. Electrical wiring and equipment located in inside
storage rooms used for Class I liquids shall be approved under Subpart S
of this part for Class I, Division 2 Hazardous Locations; for Class II
and Class III liquids, shall be approved for general use.
(iv) Ventilation. Every inside storage room shall be provided with
either a gravity or a mechanical exhaust ventilation system. Such system
shall be designed to provide for a complete change of air within the
room at least six times per hour. If a mechanical exhaust system is
used, it shall be controlled by a switch located outside of the door.
The ventilating equipment and any lighting fixtures shall be operated by
the same switch. A pilot light shall be installed adjacent to the switch
if Class I flammable liquids are dispensed within the room. Where
gravity ventilation is provided, the fresh air intake, as well as the
exhaust outlet from the room, shall be on the exterior of the building
in which the room is located.
(v) Storage in inside storage rooms. In every inside storage room
there shall be maintained 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.
(5) Storage inside building--(i) Egress. Flammable or combustible
liquids, including stock for sale, shall not be stored so as to limit
use of exits, stairways, or areas normally used for the safe egress of
people.
(ii) Containers. The storage of flammable or combustible liquids in
containers or portable tanks shall comply with subdivisions (iii)
through (v) of this subparagraph.
(iii) Office occupancies. Storage shall be prohibited except that
which is required for maintenance and operation of building and
operation of equipment. Such storage shall be kept in closed metal
containers stored in a storage cabinet or in safety cans or in an inside
storage room not having a door that opens into that portion of the
building used by the public.
(iv) Mercantile occupancies and other retail stores.
(a)-(d) [Reserved]
(e) Leaking containers shall be removed to a storage room or taken
to a safe location outside the building and the contents transferred to
an undamaged container.
(v) General purpose public warehouses. Storage shall be in
accordance with Table H-14 or H-15 and in buildings or in portions of
such buildings cut off by standard firewalls. Material creating no fire
exposure hazard to the flammable or combustible liquids may be stored in
the same area.
Table H-14--Indoor Container Storage
----------------------------------------------------------------------------------------------------------------
Gallons
---------------------------
Protected Unprotected
Class liquid Storage level storage storage
maximum per maximum per
pile pile
----------------------------------------------------------------------------------------------------------------
A............................................. Ground and upper floors............. 2,750 660
(50) (12)
Basement............................ Not Not
permitted permitted
B............................................. Ground and upper floors............. 5,500 1,375
(100) (25)
Basement............................ Not Not
permitted permitted
C............................................. Ground and upper floors............. 16,500 4,125
[[Page 253]]
(300) (75)
Basement............................ Not Not
permitted permitted
II............................................ Ground and upper floors............. 16,500 4,125
(300) (75)
Basement............................ 5,500 Not
permitted
(100)
III........................................... Ground and upper floors............. 55,000 13,750
(1,000) (250)
Basement............................ 8,250 Not
permitted
(450)
----------------------------------------------------------------------------------------------------------------
Note 1: When 2 or more classes of materials are stored in a single pile, the maximum gallonage permitted in that
pile shall be the smallest of the 2 or more separate maximum gallonages.
Note 2: Aisles shall be provided so that no container is more than 12 ft. from an aisle. Main aisles shall be at
least 3 ft. wide and side aisles at least 4 ft. wide.
Note 3: Each pile shall be separated from each other by at least 4 ft.
(Numbers in parentheses indicate corresponding number of 55-gal. drums.)
Table H-15--Indoor Portable Tank Storage
----------------------------------------------------------------------------------------------------------------
Gallons
---------------------------
Protected Unprotected
Class liquid Storage level storage storage
maximum per maximum per
pile pile
----------------------------------------------------------------------------------------------------------------
IA............................................ Ground and upper floors............. Not Not
permitted permitted
Basement............................ Not Not
permitted permitted
IB............................................ Ground and upper floors............. 20,000 2,000
Basement............................ Not Not
permitted permitted
IC............................................ Ground and upper floors............. 40,000 5,500
Basement............................ Not Not
permitted permitted
II............................................ Ground and upper floors............. 40,000 5,500
Basement............................ 20,000 Not
permitted
III........................................... Ground and upper floors............. 60,000 22,000
Basement............................ 20,000 Not
permitted
----------------------------------------------------------------------------------------------------------------
Note 1: When 1 or more classes of materials are stored in a single pile, the maximum gallonage permitted in that
pile shall be the smallest of the 2 or more separate maximum gallonages.
Note 2: Aisles shall be provided so that no portable tank is more than 12 ft. from an aisle. Main aisles shall
be at least 8 ft. wide and side aisles at least 4 ft. wide.
Note 3: Each pile shall be separated from each other by at least 4 ft.
(vi) Flammable and combustible liquid warehouses or storage
buildings. (a) If the storage building is located 50 feet or less from a
building or line of adjoining property that may be built upon, the
exposing wall shall be a blank wall having a fire-resistance rating of
at least 2 hours.
(b) The total quantity of liquids within a building shall not be
restricted, but the arrangement of storage shall comply with Table H-14
or H-15.
(c) Containers in piles shall be separated by pallets or dunnage
where necessary to provide stability and to prevent excessive stress on
container walls.
(d) Portable tanks stored over one tier high shall be designed to
nest securely, without dunnage, and adequate materials handing equipment
shall be available to handle tanks safely at the upper tier level.
(e) No pile shall be closer than 3 feet to the nearest beam, chord,
girder, or other obstruction, and shall be 3 feet below sprinkler
deflectors or discharge orifices of water spray, or other overhead fire
protection systems.
(f) Aisles of at least 3 feet wide shall be provided where necessary
for reasons of access to doors, windows or standpipe connections.
(6) Storage outside buildings--(i) General. Storage outside
buildings shall be in accordance with Table H-16 or H-17, and
subdivisions (ii) and (iv) of this subparagraph.
[[Page 254]]
Table H-16--Outdoor Container Storage
----------------------------------------------------------------------------------------------------------------
4--Distance
3--Distance to property 5--Distance
1--Class 2--Maximum between line that to street,
per pile piles can be alley,
built upon public way
----------------------------------------------------------------------------------------------------------------
gallons feet feet feet
---------------------------------------------------
IA.......................................................... 1,100 5 20 10
IB.......................................................... 2,200 5 20 10
IC.......................................................... 4,400 5 20 10
II.......................................................... 8,800 5 10 5
III......................................................... 22,000 5 10 5
----------------------------------------------------------------------------------------------------------------
Note 1: When 2 or more classes of materials are stored in a single pile, the maximum gallonage in that pile
shall be the smallest of the 2 or more separate gallonages.
Note 2: Within 200 ft. of each container, there shall be a 12-ft. wide access way to permit approach of fire
control apparatus.
Note 3: The distances listed apply to properties that have protection for exposures as defined. If there are
exposures, and such protection for exposures does not exist, the distances in column 4 shall be doubled.
Note 4: When total quantity stored does not exceed 50 percent of maximum per pile, the distances in columns 4
and 5 may be reduced 50 percent, but not less than 3 ft.
(ii) Maximum storage. A maximum of 1,100 gallons of flammable or
combustible liquids may be located adjacent to buildings located on the
same premises and under the same management provided the provisions of
subdivisions (a) and (b) of this subdivision are complied with.
(a) [Reserved]
(b) Where quantity stored exceeds 1,100 gallons, or provisions of
subdivision (a) of this subdivision cannot be met, a minimum distance of
10 feet between buildings and nearest container of flammable or
combustible liquid shall be maintained.
(iii) Spill containment. The storage area shall be graded in a
manner to divert possible spills away from buildings or other exposures
or shall be surrounded by a curb at least 6 inches high. When curbs are
used, provisions shall be made for draining of accumulations of ground
or rain water or spills of flammable or combustible liquids. Drains
shall terminate at a safe location and shall be accessible to operation
under fire conditions.
(iv) Security. The storage area shall be protected against tampering
or trespassers where necessary and shall be kept free of weeds, debris
and other combustible material not necessary to the storage.
(7) Fire control--(i) Extinguishers. Suitable fire control devices,
such as small hose or portable fire extinguishers, shall be available at
locations where flammable or combustible liquids are stored.
Table H-17--Outdoor Portable Tank Storage
----------------------------------------------------------------------------------------------------------------
4--Distance
3--Distance to property 5--Distance
1--Class 2--Maximum between line that to street,
per pile piles can be alley,
built upon public way
----------------------------------------------------------------------------------------------------------------
gallon feet feet feet
---------------------------------------------------
IA.......................................................... 2,200 5 20 10
IB.......................................................... 4,400 5 20 10
IC.......................................................... 8,800 5 20 10
II.......................................................... 17,600 5 10 5
III......................................................... 44,000 5 10 5
----------------------------------------------------------------------------------------------------------------
Note 1: When 2 or more classes of materials are stored in a single pile, the maximum gallonage in that pile
shall be the smallest of the 2 or more separate gallonages.
Note 2: Within 200 ft. of each portable tank, there shall be a 12-ft. wide access way to permit approach of fire
control apparatus.
Note 3: The distances listed apply to properties that have protection for exposures as defined. If there are
exposures, and such protection for exposures does not exist, the distances in column 4 shall be doubled.
Note 4: When total quantity stored does not exceed 50 percent of maximum per pile, the distances in columns 4
and 5 may be reduced 50 percent, but not less than 3 ft.
[[Page 255]]
(a) 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.
(b) At least one portable fire extinguisher having a rating of not
less than 12-B units must be located not less than 10 feet, nor more
than 25 feet, from any Class I or Class II liquid storage area located
outside of a storage room but inside a building.
(ii) Sprinklers. When sprinklers are provided, they shall be
installed in accordance with Sec. 1910.159.
(iii) Open flames and smoking. Open flames and smoking shall not be
permitted in flammable or combustible liquid storage areas.
(iv) Water reactive materials. Materials which will react with water
shall not be stored in the same room with flammable or combustible
liquids.
(e) Industrial plants--(1) Scope--(i) Application. This paragraph
shall apply to those industrial plants where:
(a) The use of flammable or combustible liquids is incidental to the
principal business, or
(b) Where flammable or combustible liquids are handled or used only
in unit physical operations such as mixing, drying, evaporating,
filtering, distillation, and similar operations which do not involve
chemical reaction. This paragraph shall not apply to chemical plants,
refineries or distilleries.
(ii) Exceptions. Where portions of such plants involve chemical
reactions such as oxidation, reduction, halogenation, hydrogenation,
alkylation, polymerization, and other chemical processes, those portions
of the plant shall be in accordance with paragraph (h) of this section.
(2) Incidental storage or use of flammable and combustible liquids--
(i) Application. This subparagraph shall be applicable to those portions
of an industrial plant where the use and handling of flammable or
combustible liquids is only incidental to the principal business, such
as automobile assembly, construction of electronic equipment, furniture
manufacturing, or other similar activities.
(ii) Containers. Flammable or combustible liquids shall be stored in
tanks or closed containers.
(a) Except as provided in subdivisions (b) and (c) of this
subdivision, all storage shall comply with paragraph (d) (3) or (4) of
this section.
(b) 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:
(1) 25 gallons of Class IA liquids in containers
(2) 120 gallons of Class IB, IC, II, or III liquids in containers
(3) 660 gallons of Class IB, IC, II, or III liquids in a single
portable tank.
(c) Where large quantities of flammable or combustible liquids are
necessary, storage may be in tanks which shall comply with the
applicable requirements of paragraph (b) of this section.
(iii) Separation and protection. Areas in which flammable or
combustible liquids are transferred from one tank or container to
another container shall be separated from other operations in the
building by adequate distance or by construction having adequate fire
resistance. Drainage or other means shall be provided to control spills.
Adequate natural or mechanical ventilation shall be provided.
(iv) Handling liquids at point of final use. (a) Flammable liquids
shall be kept in covered containers when not actually in use.
(b) Where flammable or combustible liquids are used or handled,
except in closed containers, means shall be provided to dispose promptly
and safely of leakage or spills.
(c) Class I liquids may be used only where there are no open flames
or other sources of ignition within the possible path of vapor travel.
(d) Flammable or combustible liquids shall be drawn from or
transferred into vessels, containers, or portable tanks within a
building only through a closed piping system, from safety cans, by means
of a device drawing through the top, or from a container or portable
tanks by gravity through an approved self-closing valve. Transferring by
means of air pressure on the container or portable tanks shall be
prohibited.
[[Page 256]]
(3) Unit physical operations--(i) Application. This subparagraph
shall be applicable in those portions of industrial plants where
flammable or combustible liquids are handled or used in unit physical
operations such as mixing, drying, evaporating, filtering, distillation,
and similar operations which do not involve chemical change. Examples
are plants compounding cosmetics, pharmaceuticals, solvents, cleaning
fluids, insecticides, and similar types of activities.
(ii) Location. Industrial plants shall be located so that each
building or unit of equipment is accessible from at least one side for
firefighting and fire control purposes. Buildings shall be located with
respect to lines of adjoining property which may be built upon as set
forth in paragraph (h)(2) (i) and (ii) of this section except that the
blank wall referred to in paragraph (h)(2)(ii) of this section shall
have a fire resistance rating of at least 2 hours.
(iii) Chemical processes. Areas where unstable liquids are handled
or small scale unit chemical processes are carried on shall be separated
from the remainder of the plant by a fire wall of 2-hour minimum fire
resistance rating.
(iv) Drainage. (a) Emergency drainage systems shall be provided to
direct flammable or combustible liquid leakage and fire protection water
to a safe location. This may require curbs, scuppers, or special
drainage systems to control the spread of fire; see paragraph
(b)(2)(vii)(b) of this section.
(b) Emergency drainage systems, if connected to public sewers or
discharged into public waterways, shall be equipped with traps or
separator.
(v) Ventilation. (a) Areas as defined in subdivision (i) of this
subparagraph using Class I liquids shall be ventilated at a rate of not
less than 1 cubic foot per minute per square foot of solid floor area.
This shall be accomplished by natural or mechanical ventilation with
discharge or exhaust to a safe location outside of the building.
Provision shall be made for introduction of makeup air in such a manner
as not to short circuit the ventilation. Ventilation shall be arranged
to include all floor areas or pits where flammable vapors may collect.
(b) Equipment used in a building and the ventilation of the building
shall be designed so as to limit flammable vapor-air mixtures under
normal operating conditions to the interior of equipment, and to not
more than 5 feet from equipment which exposes Class I liquids to the
air. Examples of such equipment are dispensing stations, open
centrifuges, plate and frame filters, open vacuum filters, and surfaces
of open equipment.
(vi) Storage and handling. The storage, transfer, and handling of
liquid shall comply with paragraph (h)(4) of this section.
(4) Tank vehicle and tank car loading and unloading. (i) Tank
vehicle and tank car loading or unloading facilities shall be separated
from aboveground tanks, warehouses, other plant buildings or nearest
line of adjoining property which may be built upon by a distance of 25
feet for Class I liquids and 15 feet for Class II and Class III liquids
measured from the nearest position of any fill stem. Buildings for pumps
or shelters for personnel may be a part of the facility. Operations of
the facility shall comply with the appropriate portions of paragraph
(f)(3) of this section.
(ii) [Reserved]
(5) Fire control--(i) Portable and special equipment. Portable fire
extinguishment and control equipment shall be provided in such
quantities and types as are needed for the special hazards of operation
and storage.
(ii) Water supply. Water shall be available in volume and at
adequate pressure to supply water hose streams, foam-producing
equipment, automatic sprinklers, or water spray systems as the need is
indicated by the special hazards of operation, dispensing and storage.
(iii) Special extinguishers. Special extinguishing equipment such as
that utilizing foam, inert gas, or dry chemical shall be provided as the
need is indicated by the special hazards of operation dispensing and
storage.
(iv) Special hazards. Where the need is indicated by special hazards
of operation, flammable or combustible liquid processing equipment,
major piping, and supporting steel shall be protected by approved water
spray systems, deluge systems, approved fire-resistant
[[Page 257]]
coatings, insulation, or any combination of these.
(v) Maintenance. All plant fire protection facilities shall be
adequately maintained and periodically inspected and tested to make sure
they are always in satisfactory operating condition, and they will serve
their purpose in time of emergency.
(6) Sources of ignition--(i) General. Adequate precautions shall be
taken to prevent the ignition of flammable vapors. Sources of ignition
include but are not limited to 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.
(ii) Grounding. Class I liquids shall not be dispensed into
containers unless the nozzle and container are electrically
interconnected. Where the metallic floorplate on which the container
stands while filling is electrically connected to the fill stem or where
the fill stem is bonded to the container during filling operations by
means of a bond wire, the provisions of this section shall be deemed to
have been complied with.
(7) Electrical--(i) Equipment. (a) All electrical wiring and
equipment shall be installed according to the requirements of Subpart S
of this part.
(b) Locations where flammable vapor-air mixtures may exist under
normal operations shall be classified Class I, Division 1 according to
the requirements of Subpart S of this part. For those pieces of
equipment installed in accordance with subparagraph (3)(v)(b) of this
paragraph, the Division 1 area shall extend 5 feet in all directions
from all points of vapor liberation. All areas within pits shall be
classified Division 1 if any part of the pit is within a Division 1 or 2
classified area, unless the pit is provided with mechanical ventilation.
(c) Locations where flammable vapor-air mixtures may exist under
abnormal conditions and for a distance beyond Division 1 locations shall
be classified Division 2 according to the requirements of Subpart S of
this part. These locations include an area within 20 feet horizontally,
3 feet vertically beyond a Division 1 area, and up to 3 feet above floor
or grade level within 25 feet, if indoors, or 10 feet if outdoors, from
any pump, bleeder, withdrawal fitting, meter, or similar device handling
Class I liquids. Pits provided with adequate mechanical ventilation
within a Division 1 or 2 area shall be classified Division 2. If Class
II or Class III liquids only are handled, then ordinary electrical
equipment is satisfactory though care shall be used in locating
electrical apparatus to prevent hot metal from falling into open
equipment.
(d) Where the provisions of subdivisions (a), (b), and (c), of this
subdivision require the installation of electrical equipment suitable
for Class I, Division 1 or Division 2 locations, ordinary electrical
equipment including switchgear may be used if installed in a room or
enclosure which is maintained under positive pressure with respect to
the hazardous area. Ventilation makeup air shall be uncontaminated by
flammable vapors.
(8) Repairs to equipment. Hot work, such as welding or cutting
operations, use of spark-producing power tools, and chipping operations
shall be permitted only under supervision of an individual in
responsible charge. The individual in responsible charge shall make an
inspection of the area to be sure that it is safe for the work to be
done and that safe procedures will be followed for the work specified.
(9) Housekeeping--(i) General. Maintenance and operating practices
shall be in accordance with established procedures which will tend to
control leakage and prevent the accidental escape of flammable or
combustible liquids. Spills shall be cleaned up promptly.
(ii) Access. Adequate aisles shall be maintained for unobstructed
movement of personnel and so that fire protection equipment can be
brought to bear on any part of flammable or combustible liquid storage,
use, or any unit physical operation.
(iii) Waste and residue. Combustible waste material and residues in
a building or unit operating area shall be kept to a minimum, stored in
covered metal receptacles and disposed of daily.
(iv) Clear zone. Ground area around buildings and unit operating
areas shall be kept free of weeds, trash, or
[[Page 258]]
other unnecessary combustible materials.
(f) Bulk plants--(1) Storage--(i) Class I liquids. Class I liquids
shall be stored in closed containers, or in storage tanks above ground
outside of buildings, or underground in accordance with paragraph (b) of
this section.
(ii) Class II and III liquids. Class II and Class III liquids shall
be stored in containers, or in tanks within buildings or above ground
outside of buildings, or underground in accordance with paragraph (b) of
this section.
(iii) Piling containers. Containers of flammable or combustible
liquids when piled one upon the other shall be separated by dunnage
sufficient to provide stability and to prevent excessive stress on
container walls. The height of the pile shall be consistent with the
stability and strength of containers.
(2) Buildings--(i) Exits. Rooms in which flammable or combustible
liquids are stored or handled by pumps shall have exit facilities
arranged to prevent occupants from being trapped in the event of fire.
(ii) Heating. Rooms in which Class I liquids are stored or handled
shall be heated only by means not constituting a source of ignition,
such as steam or hot water. Rooms containing heating appliances
involving sources of ignition shall be located and arranged to prevent
entry of flammable vapors.
(iii) Ventilation. (a) Ventilation shall be provided for all rooms,
buildings, or enclosures in which Class I liquids are pumped or
dispensed. Design of ventilation systems shall take into account the
relatively high specific gravity of the vapors. Ventilation may be
provided by adequate openings in outside walls at floor level
unobstructed except by louvers or coarse screens. Where natural
ventilation is inadequate, mechanical ventilation shall be provided.
(b) Class I liquids shall not be stored or handled within a building
having a basement or pit into which flammable vapors may travel, unless
such area is provided with ventilation designed to prevent the
accumulation of flammable vapors therein.
(c) Containers of Class I liquids shall not be drawn from or filled
within buildings unless provision is made to prevent the accumulation of
flammable vapors in hazardous concentrations. Where mechanical
ventilation is required, it shall be kept in operation while flammable
liquids are being handled.
(3) Loading and unloading facilities--(i) Separation. Tank vehicle
and tank car loading or unloading facilities shall be separated from
aboveground tanks, warehouses, other plant buildings or nearest line of
adjoining property that may be built upon by a distance of 25 feet for
Class I liquids and 15 feet for Class II and Class III liquids measured
from the nearest position of any fill spout. Buildings for pumps or
shelters for personnel may be a part of the facility.
(ii) Class restriction. Equipment such as piping, pumps, and meters
used for the transfer of Class I liquids between storage tanks and the
fill stem of the loading rack shall not be used for the transfer of
Class II or Class III liquids.
(iii) Valves. Valves used for the final control for filling tank
vehicles shall be of the self-closing type and manually held open except
where automatic means are provided for shutting off the flow when the
vehicle is full or after filling of a preset amount.
(iv) Static protection. (a) Bonding facilities for protection
against static sparks during the loading of tank vehicles through open
domes shall be provided:
(1) Where Class I liquids are loaded, or
(2) Where Class II or Class III liquids are loaded into vehicles
which may contain vapors from previous cargoes of Class I liquids.
(b) Protection as required in (a) of this subdivision (iv) shall
consist of a metallic bond wire permanently electrically connected to
the fill stem or to some part of the rack structure in electrical
contact with the fill stem. The free end of such wire shall be provided
with a clamp or equivalent device for convenient attachment to some
metallic part in electrical contact with the cargo tank of the tank
vehicle.
(c) Such bonding connection shall be made fast to the vehicle or
tank before dome covers are raised and shall remain in place until
filling is completed and all dome covers have been closed and secured.
[[Page 259]]
(d) Bonding as specified in (a), (b), and (c) of this subdivision is
not required:
(1) Where vehicles are loaded exclusively with products not having a
static accumulating tendency, such as asphalt, most crude oils, residual
oils, and water soluble liquids;
(2) Where no Class I liquids are handled at the loading facility and
the tank vehicles loaded are used exclusively for Class II and Class III
liquids; and
(3) Where vehicles are loaded or unloaded through closed bottom or
top connections.
(e) Filling through open domes into the tanks of tank vehicles or
tank cars, that contain vapor-air mixtures within the flammable range or
where the liquid being filled can form such a mixture, shall be by means
of a downspout which extends near the bottom of the tank. This
precaution is not required when loading liquids which are
nonaccumulators of static charges.
(v) Stray currents. Tank car loading facilities where Class I
liquids are loaded through open domes shall be protected against stray
currents by bonding the pipe to at least one rail and to the rack
structure if of metal. Multiple lines entering the rack area shall be
electrically bonded together. In addition, in areas where excessive
stray currents are known to exist, all pipe entering the rack area shall
be provided with insulating sections to electrically isolate the rack
piping from the pipelines. No bonding between the tank car and the rack
or piping is required during either loading or unloading of Class II or
III liquids.
(vi) Container filling facilities. Class I liquids shall not be
dispensed into containers unless the nozzle and container are
electrically interconnected. Where the metallic floorplate on which the
container stands while filling is electrically connected to the fill
stem or where the fill stem is bonded to the container during filling
operations by means of a bond wire, the provisions of this section shall
be deemed to have been complied with.
(4) Wharves--(i) Definition, application. The term wharf shall mean
any wharf, pier, bulkhead, or other structure over or contiguous to
navigable water used in conjunction with a bulk plant, the primary
function of which is the transfer of flammable or combustible liquid
cargo in bulk between the bulk plant and any tank vessel, ship, barge,
lighter boat, or other mobile floating craft; and this subparagraph
shall apply to all such installations except Marine Service Stations as
covered in paragraph (g) of this section.
(ii)-(iii) [Reserved]
(iv) Design and construction. Substructure and deck shall be
substantially designed for the use intended. Deck may employ any
material which will afford the desired combination of flexibility,
resistance to shock, durability, strength, and fire resistance. Heavy
timber construction is acceptable.
(v) [Reserved]
(vi) Pumps. Loading pumps capable of building up pressures in excess
of the safe working pressure of cargo hose or loading arms shall be
provided with bypasses, relief valves, or other arrangement to protect
the loading facilities against excessive pressure. Relief devices shall
be tested at not more than yearly intervals to determine that they
function satisfactorily at the pressure at which they are set.
(vii) Hoses and couplings. All pressure hoses and couplings shall be
inspected at intervals appropriate to the service. The hose and
couplings shall be tested with the hose extended and using the
``inservice maximum operating pressures.'' Any hose showing material
deteriorations, signs of leakage, or weakness in its carcass or at the
couplings shall be withdrawn from service and repaired or discarded.
(viii) Piping and fittings. Piping, valves, and fittings shall be in
accordance with paragraph (c) of this section, with the following
exceptions and additions:
(a) Flexibility of piping shall be assured by appropriate layout and
arrangement of piping supports so that motion of the wharf structure
resulting from wave action, currents, tides, or the mooring of vessels
will not subject the pipe to repeated strain beyond the elastic limit.
(b) Pipe joints depending upon the friction characteristics of
combustible materials or grooving of pipe ends for
[[Page 260]]
mechanical continuity of piping shall not be used.
(c) Swivel joints may be used in piping to which hoses are
connected, and for articulated swivel-joint transfer systems, provided
that the design is such that the mechanical strength of the joint will
not be impaired if the packing material should fail, as by exposure to
fire.
(d) Piping systems shall contain a sufficient number of valves to
operate the system properly and to control the flow of liquid in normal
operation and in the event of physical damage.
(e) In addition to the requirements of subdivision (d) of this
subdivision, each line conveying flammable liquids leading to a wharf
shall be provided with a readily accessible block valve located on shore
near the approach to the wharf and outside of any diked area. Where more
than one line is involved, the valves shall be grouped in one location.
(f) Means of easy access shall be provided for cargo line valves
located below the wharf deck.
(g) Pipelines on flammable or combustible liquids wharves shall be
adequately bonded and grounded. If excessive stray currents are
encountered, insulating joints shall be installed. Bonding and grounding
connections on all pipelines shall be located on wharfside of hose-riser
insulating flanges, if used, and shall be accessible for inspection.
(h) Hose or articulated swivel-joint pipe connections used for cargo
transfer shall be capable of accommodating the combined effects of
change in draft and maximum tidal range, and mooring lines shall be kept
adjusted to prevent the surge of the vessel from placing stress on the
cargo transfer system.
(i) Hose shall be supported so as to avoid kinking and damage from
chafing.
(ix) Fire protection. Suitable portable fire extinguishers with a
rating of not less than 12-BC shall be located within 75 feet of those
portions of the facility where fires are likely to occur, such as hose
connections, pumps, and separator tanks.
(a) Where piped water is available, ready-connected fire hose in
size appropriate for the water supply shall be provided so that
manifolds where connections are made and broken can be reached by at
least one hose stream.
(b) Material shall not be placed on wharves in such a manner as to
obstruct access to firefighting equipment, or important pipeline control
valves.
(c) Where the wharf is accessible to vehicle traffic, an
unobstructed roadway to the shore end of the wharf shall be maintained
for access of firefighting apparatus.
(x) Operations control. Loading or discharging shall not commence
until the wharf superintendent and officer in charge of the tank vessel
agree that the tank vessel is properly moored and all connections are
properly made. Mechanical work shall not be performed on the wharf
during cargo transfer, except under special authorization based on a
review of the area involved, methods to be employed, and precautions
necessary.
(5) Electrical equipment--(i) Application. This subparagraph shall
apply to areas where Class I liquids are stored or handled. For areas
where Class II or Class III liquids only are stored or handled, the
electrical equipment may be installed in accordance with the provisions
of Subpart S of this part, for ordinary locations.
(ii) Conformance. All electrical equipment and wiring shall be of a
type specified by and shall be installed in accordance with Subpart S of
this part.
(iii) Classification. So far as it applies Table H-18 shall be used
to delineate and classify hazardous areas for the purpose of
installation of electrical equipment under normal circumstances. In
Table H-18 a classified area shall not extend beyond an unpierced wall,
roof, or other solid partition. The area classifications listed shall be
based on the premise that the installation meets the applicable
requirements of this section in all respects.
(6) Sources of ignition. Class I liquids shall not be handled,
drawn, or dispensed where flammable vapors may reach a source of
ignition. Smoking shall be prohibited except in designated localities.
``No Smoking'' signs shall be conspicuously posted where hazard from
flammable liquid vapors is normally present.
[[Page 261]]
(7) Drainage and waste disposal. Provision shall be made to prevent
flammable or combustible liquids which may be spilled at loading or
unloading points from entering public sewers and drainage systems, or
natural waterways. Connection to such sewers, drains, or waterways by
which flammable or combustible liquids might enter shall be provided
with separator boxes or other approved means whereby such entry is
precluded. Crankcase drainings and flammable or combustible liquids
shall not be dumped into sewers, but shall be stored in tanks or tight
drums outside of any building until removed from the premises.
(8) Fire control. Suitable fire-control devices, such as small hose
or portable fire extinguishers, shall be available to locations where
fires are likely to occur. Additional fire-control equipment may be
required where a tank of more than 50,000 gallons individual capacity
contains Class I liquids and where an unusual exposure hazard exists
from surrounding property. Such additional fire-control equipment shall
be sufficient to extinguish a fire in the largest tank. The design and
amount of such equipment shall be in accordance with approved
engineering standards.
(g) Service stations--(1) Storage and handling--(i) General
provisions. (a) Liquids shall be stored in approved closed containers
not exceeding 60 gallons capacity, in tanks located underground, in
tanks in special enclosures as described in paragraph (g)(i) of this
section, or in aboveground tanks as provided for in paragraphs
(g)(4)(ii), (b), (c) and (d) of this section.
(b) Aboveground tanks, located in an adjoining bulk plant, may be
connected by piping to service station underground tanks if, in addition
to valves at aboveground tanks, a valve is also installed within control
of service station personnel.
(c) Apparatus dispensing Class I liquids into the fuel tanks of
motor vehicles of the public shall not be located at a bulk plant unless
separated by a fence or similar barrier from the area in which bulk
operations are conducted.
(d) [Reserved]
(e) The provisions of paragraph (g)(1)(i)(a) of this section shall
not prohibit the dispensing of flammable liquids in the open from a tank
vehicle to a motor vehicle. Such dispensing shall be permitted provided:
(1) The tank vehicle complies with the requirements covered in the
Standard on Tank Vehicles for Flammable Liquids, NFPA 385-1966.
(2) The dispensing is done on premises not open to the public.
(3) [Reserved]
(4) The dispensing hose does not exceed 50 feet in length.
(5) The dispensing nozzle is a listed automatic-closing type without
a latchopen device.
(f) Class I liquids shall not be stored or handled within a building
having a basement or pit into which flammable vapors may travel, unless
such area is provided with ventilation designed to prevent the
accumulation of flammable vapors therein.
(g) [Reserved]
Table H-18--Electrical Equipment Hazardous Areas--Bulk Plants
------------------------------------------------------------------------
Class I
Location Group D Extent of classified area
division
------------------------------------------------------------------------
Tank vehicle and tank car:
\1\
Loading through open dome.. 1 Within 3 feet of edge of
dome, extending in all
directions.
2 Area between 3 feet and 5
feet from edge of dome,
extending in all directions.
Loading through bottom 1 Within 3 feet of point of
connections with venting to atmosphere
atmospheric venting. extending in all directions.
2 Area between 3 feet and 5
feet from point of venting
to atmosphere, extending in
all directions. Also up to
18 inches above grade within
a horizontal radius of 10
feet from point of loading
connection.
Loading through closed dome 1 Within 3 feet of open end of
with atmospheric venting. 2 vent, extending in all
directions.
Area between 3 feet and 5
feet from open end of vent,
extending in all directions.
Also within 3 feet of edge
of dome, extending in all
directions.
[[Page 262]]
Loading through closed dome 2 Within 3 feet of point of
with vapor recovery. connection of both fill and
vapor lines, extending in
all directions.
Bottom loading with vapor 2 Within 3 feet of point of
recovery or any bottom connections extending in all
unloading. directions. Also up to 18
inches above grade with in a
horizontal radius of 10 feet
from point of connection.
Drum and container filling:
Outdoors, or indoors with 1 Within 3 feet of vent and
adequate ventilation. fill opening, extending in
all directions.
2 Area between 3 feet and 5
feet from vent or fill
opening, extending in all
directions. Also up to 18
inches above floor or grade
level within a horizontal
radius of 10 feet from vent
or fill opening.
Outdoors, or indoors with 1 Within 3 feet of vent and
adequate ventilation. fill opening, extending in
all directions.
2 Area between 3 feet and 5
feet from vent or fill
opening, extending in all
directions. Also up to 18
inches above floor or grade
level within a horizontal
radius of 10 feet from vent
or fill opening.
Tank--Aboveground:
Shell, ends, or roof and 2 Within 10 feet from shell,
dike area. ends, or roof of tank, Area
inside dikes to level of top
of dike.
Vent....................... 1 Within 5 feet of open end of
vent, extending in all
directions.
2 Area between 5 feet and 10
feet from open end of vent,
extending in all directions.
Floating roof.............. 1 Area above the roof and
within the shell.
Pits:
Without mechanical 1 Entire area within pit if any
ventilation. part is within a Division 1
or 2 classified area.
With mechanical ventilation 2 Entire area within pit if any
part is within a Division 1
or 2 classified area.
Containing valves, fittings 2 Entire pit.
or piping, and not within
a Division 1 or 2
classified area.
Pumps, bleeders, withdrawal
fittings, meters and similar
devices:
Indoors.................... 2 Within 5 feet of any edge of
such devices, extending in
all directions. Also up to 3
feet above floor or grade
level within 25 feet
horizontally from any edge
of such devices.
Outdoors................... 2 Within 3 feet of any edge of
such devices, extending in
all directions. Also up to
18 inches above grade level
within 10 feet horizontally
from any edge of such
devices.
Storage and repair garage 1 All pits or spaces below
for tank vehicles. floor level.
2 Area up to 18 inches above
floor or grade level for
entire storage or repair
garage.
Drainage ditches, 2 Area up to 18 inches above
separators, impounding ditch, separator or basin.
basins. Also up to 18 inches above
grade within 15 feet
horizontally from any edge.
Garages for other than tank (\2\ ) If there is any opening to
vehicles. these rooms within the
extent of an outdoor
classified area, the entire
room shall be classified the
same as the area
classification at the point
of the opening.
Outdoor drum storage....... (\2\ )
Indoor warehousing where (\2\ ) If there is any opening to
there is no flammable these rooms within the
liquid transfer. extent of an indoor
classified are, the room
shall be classified the same
as if the wall, curb or
partition did not exist.
Office and rest rooms...... (\2\ )
------------------------------------------------------------------------
\1\ When classifying the extent of the area, consideration shall be
given to the fact that tank cars or tank vehicles may be spotted at
varying points. Therefore, the extremities of the loading or unloading
positions shall be used.
\2\ Ordinary.
(ii) Special enclosures. (a) When installation of tanks in
accordance with paragraph (b)(3) of this section is impractical because
of property or building limitations, tanks for flammable or combustible
liquids may be installed in buildings if properly enclosed.
(b) The enclosure shall be substantially liquid and vaportight
without backfill. Sides, top, and bottom of the enclosure shall be of
reinforced concrete at least 6 inches thick, with openings for
inspection through the top only. Tank connections shall be so
[[Page 263]]
piped or closed that neither vapors nor liquid can escape into the
enclosed space. Means shall be provided whereby portable equipment may
be employed to discharge to the outside any liquid or vapors which might
accumulate should leakage occur.
(iii) Inside buildings. (a) Except where stored in tanks as provided
in subdivision (ii) of this subparagraph, no Class I liquids shall be
stored within any service station building except in closed containers
of aggregate capacity not exceeding 60 gallons. One container not
exceeding 60 gallons capacity equipped with an approved pump is
permitted.
(b) Class I liquids may be transferred from one container to another
in lubrication or service rooms of a service station building provided
the electrical installation complies with Table H-19 and provided that
any heating equipment complies with subparagraph (6) of this paragraph.
(c) Class II and Class III liquids may be stored and dispensed
inside service station buildings from tanks of not more than 120 gallons
capacity each.
(iv) [Reserved]
(v) Dispensing into portable containers. No delivery of any Class I
liquids shall be made into portable containers unless the container is
constructed of metal, has a tight closure with screwed or spring cover,
and is fitted with a spout or so designed that the contents can be
poured without spilling.
(2) [Reserved]
(3) Dispensing systems--(i) Location. Dispensing devices at
automotive service stations shall be so located that all parts of the
vehicle being served will be on the premises of the service station.
(ii) Inside location. Approved dispensing units may be located
inside of buildings. The dispensing area shall be separated from other
areas in an approved manner. The dispensing unit and its piping shall be
mounted either on a concrete island or protected against collision
damage by suitable means and shall be located in a position where it
cannot be struck by a vehicle descending a ramp or other slope out of
control. The dispensing area shall be provided with an approved
mechanical or gravity ventilation system. When dispensing units are
located below grade, only approved mechanical ventilation shall be used
and the entire dispensing area shall be protected by an approved
automatic sprinkler system. Ventilating systems shall be electrically
interlocked with gasoline dispensing units so that the dispensing units
cannot be operated unless the ventilating fan motors are energized.
(iii) Emergency power cutoff. A clearly identified and easily
accessible switch(es) or a circuit breaker(s) shall be provided at a
location remote from dispensing devices, including remote pumping
systems, to shut off the power to all dispensing devices in the event of
an emergency.
(iv) Dispensing units. (a) Class I liquids shall be transferred from
tanks by means of fixed pumps so designed and equipped as to allow
control of the flow and to prevent leakage or accidental discharge.
(b)(1) Only listed devices may be used for dispensing Class I
liquids. No such device may be used if it shows evidence of having been
dismantled.
(2) Every dispensing device for Class I liquids installed after
December 31, 1978, shall contain evidence of listing so placed that any
attempt to dismantle the device will result in damage to such evidence,
visible without disassembly or dismounting of the nozzle.
(c) Class I liquids shall not be dispensed by pressure from drums,
barrels, and similar containers. Approved pumps taking suction through
the top of the container or approved self-closing faucets shall be used.
(d) The dispensing units, except those attached to containers, shall
be mounted either on a concrete island or protected against collision
damage by suitable means.
(v) Remote pumping systems.
(a) This subdivision shall apply to systems for dispensing Class I
liquids where such liquids are transferred from storage to individual or
multiple dispensing units by pumps located elsewhere than at the
dispensing units.
(b) Pumps shall be designed or equipped so that no part of the
system will be subjected to pressures above its allowable working
pressure. Pumps installed above grade, outside of buildings, shall be
located not less than 10
[[Page 264]]
feet from lines of adjoining property which may be built upon, and not
less than 5 feet from any building opening. When an outside pump
location is impractical, pumps may be installed inside of buildings, as
provided for dispensers in subdivision (ii) of this subparagraph, or in
pits as provided in subdivision (c) of this subdivision. Pumps shall be
substantially anchored and protected against physical damage by
vehicles.
(c) Pits for subsurface pumps or piping manifolds of submersible
pumps shall withstand the external forces to which they may be subjected
without damage to the pump, tank, or piping. The pit shall be no larger
than necessary for inspection and maintenance and shall be provided with
a fitted cover.
(d) A control shall be provided that will permit the pump to operate
only when a dispensing nozzle is removed from its bracket on the
dispensing unit and the switch on this dispensing unit is manually
actuated. This control shall also stop the pump when all nozzles have
been returned to their brackets.
(e) An approved impact valve, incorporating a fusible link, designed
to close automatically in the event of severe impact or fire exposure
shall be properly installed in the dispensing supply line at the base of
each individual dispensing device.
(f) Testing. After the completion of the installation, including any
paving, that section of the pressure piping system between the pump
discharge and the connection for the dispensing facility shall be tested
for at least 30 minutes at the maximum operating pressure of the system.
Such tests shall be repeated at 5-year intervals thereafter.
(vi) Delivery nozzles. (a) A listed manual or automatic-closing type
hose nozzle valve shall be provided on dispensers used for the
dispensing of Class I liquids.
(b) Manual-closing type valves shall be held open manually during
dispensing. Automatic-closing type valves may be used in conjunction
with an approved latch-open device.
(4) Marine service stations--(i) Dispensing. (a) The dispensing area
shall be located away from other structures so as to provide room for
safe ingress and egress of craft to be fueled. Dispensing units shall in
all cases be at least 20 feet from any activity involving fixed sources
of ignition.
(b) Dispensing shall be by approved dispensing units with or without
integral pumps and may be located on open piers, wharves, or floating
docks or on shore or on piers of the solid fill type.
(c) Dispensing nozzles shall be automatic-closing without a hold-
open latch.
(ii) Tanks and pumps. (a) Tanks, and pumps not integral with the
dispensing unit, shall be on shore or on a pier of the solid fill type,
except as provided in paragraphs (g)(4)(ii) (b) and (c) of this section.
(b) Where shore location would require excessively long supply lines
to dispensers, tanks may be installed on a pier provided that applicable
portions of paragraph (b) of this section relative to spacing, diking,
and piping are complied with and the quantity so stored does not exceed
1,100 gallons aggregate capacity.
(c) Shore tanks supplying marine service stations may be located
above ground, where rock ledges or high water table make underground
tanks impractical.
(d) Where tanks are at an elevation which would produce gravity head
on the dispensing unit, the tank outlet shall be equipped with a
pressure control valve positioned adjacent to and outside the tank block
valve specified in paragraph (b)(2)(ix)(b) of this section, so adjusted
that liquid cannot flow by gravity from the tank in case of piping or
hose failure.
(iii) Piping. (a) Piping between shore tanks and dispensing units
shall be as described in paragraph (c) of this section, except that,
where dispensing is from a floating structure, suitable lengths of oil-
resistant flexible hose may be employed between the shore piping and the
piping on the floating structure as made necessary by change in water
level or shoreline.
[[Page 265]]
Table H-19--Electrical Equipment Hazardous Areas--Service Stations
------------------------------------------------------------------------
Class I
Location Group D Extent of classified area
division
------------------------------------------------------------------------
Underground tank:
Fill opening............... 1 Any pit, box or space below
grade level, any part of
which is within the Division
1 or 2 classified area.
2 Up to 18 inches above grade
level within a horizontal
radius of 10 feet from a
loose fill connection and
within a horizontal radius
of 5 feet from a tight fill
connection.
Vent--Discharging upward... 1 Within 3 feet of open end of
vent, extending in all
directions.
2 Area between 3 feet and 5
feet of open end of vent,
extending in all directions.
Dispenser:
Pits....................... 1 Any pit, box or space below
grade level, any part of
which is within the Division
1 or 2 classified area.
Dispenser enclosure........ 1 The area 4 feet vertically
above base within the
enclosure and 18 inches
horizontally in all
directions.
Outdoor.................... 2 Up to 18 inches above grade
level within 20 feet
horizontally of any edge of
enclosure.
Indoor:
With mechanical ventilation 2 Up to 18 inches above grade
or floor level within 20
feet horizontally of any
edge of enclosure.
With gravity ventilation... 2 Up to 18 inches above grade
or floor level within 25
feet horizontally of any
edge of enclosure.
Remote pump--Outdoor....... 1 Any pit, box or space below
grade level if any part is
within a horizontal distance
of 10 feet from any edge of
pump.
2 Within 3 feet of any edge of
pump, extending in all
directions. Also up to 18
inches above grade level
within 10 feet horizontally
from any edge of pump.
Remote pump--Indoor........ 1 Entire area within any pit.
2 Within 5 feet of any edge of
pump, extending in all
directions. Also up to 3
feet above floor or grade
level within 25 feet
horizontally from any edge
of pump.
Lubrication or service room 1 Entire area within any pit.
2 Area up to 18 inches above
floor or grade level within
entire lubrication room.
Dispenser for Class I 2 Within 3 feet of any fill or
liquids. dispensing point, extending
in all directions.
Special enclosure inside 1 Entire enclosure.
building per Sec. 1910.-
106(f)(1)(ii).
Sales, storage and rest (\1\ ) If there is any opening to
rooms. these rooms within the
extent of a Division 1 area,
the entire room shall be
classified as Division 1.
------------------------------------------------------------------------
\1\ Ordinary.
(b) A readily accessible valve to shut off the supply from shore
shall be provided in each pipeline at or near the approach to the pier
and at the shore end of each pipeline adjacent to the point where
flexible hose is attached.
(c) Piping shall be located so as to be protected from physical
damage.
(d) Piping handling Class I liquids shall be grounded to control
stray currents.
(5) Electrical equipment--(i) Application. This subparagraph shall
apply to areas where Class I liquids are stored or handled. For areas
where Class II or Class III liquids are stored or handled the electrical
equipment may be installed in accordance with the provisions of subpart
S of this part, for ordinary locations.
(ii) All electrical equipment and wiring shall be of a type
specified by and shall be installed in accordance with subpart S of this
part.
(iii) So far as it applies. Table H-19 shall be used to delineate
and classify hazardous areas for the purpose of installation of
electrical equipment under normal circumstances. A classified area shall
not extend beyond an unpierced wall, roof, or other solid partition.
(iv) The area classifications listed shall be based on the
assumption that the installation meets the applicable requirements of
this section in all respects.
[[Page 266]]
(6) Heating equipment--(i) Conformance. Heating equipment shall be
installed as provided in paragraphs (g)(6) (ii) through (v) of this
section.
(ii) Application. Heating equipment may be installed in the
conventional manner in an area except as provided in paragraph (g)(6)
(iii), (iv), or (v) of this section.
(iii) Special room. Heating equipment may be installed in a special
room separated from an area classified by Table H-19 by walls having a
fire resistance rating of at least 1 hour and without any openings in
the walls within 8 feet of the floor into an area classified in Table H-
19. This room shall not be used for combustible storage and all air for
combustion purposes shall come from outside the building.
(iv) Work areas. Heating equipment using gas or oil fuel may be
installed in the lubrication, sales, or service room where there is no
dispensing or transferring of Class I liquids provided the bottom of the
combustion chamber is at least 18 inches above the floor and the heating
equipment is protected from physical damage by vehicles. Heating
equipment using gas or oil fuel listed for use in garages may be
installed in the lubrication or service room where Class I liquids are
dispensed provided the equipment is installed at least 8 feet above the
floor.
(v) Electric heat. Electrical heating equipment shall conform to
paragraph (g)(5) of this section.
(7) Drainage and waste disposal. Provision shall be made in the area
where Class I liquids are dispensed to prevent spilled liquids from
flowing into the interior of service station buildings. Such provision
may be by grading driveways, raising door sills, or other equally
effective means. Crankcase drainings and flammable or combustible
liquids shall not be dumped into sewers but shall be stored in tanks or
drums outside of any building until removed from the premises.
(8) Sources of ignition. In addition to the previous restrictions of
this paragraph, the following shall apply: There shall be no smoking or
open flames in the areas used for fueling, servicing fuel systems for
internal combustion engines, receiving or dispensing of flammable or
combustible liquids. Conspicuous and legible signs prohibiting smoking
shall be posted within sight of the customer being served. The motors of
all equipment being fueled shall be shut off during the fueling
operation.
(9) Fire control. Each service station shall be provided with at
least one fire extinguisher having a minimum approved classification of
6 B, C, located so that an extinguisher, will be within 75 feet of each
pump, dispenser, underground fill pipe opening, and lubrication or
service room.
(h) Processing plants--(1) Scope. This paragraph shall apply to
those plants or buildings which contain chemical operations such as
oxidation, reduction, halogenation, hydrogenation, alkylation,
polymerization, and other chemical processes but shall not apply to
chemical plants, refineries or distilleries.
(2) Location--(i) Classification. The location of each processing
vessel shall be based upon its flammable or combustible liquid capacity.
(ii) [Reserved]
(3) Processing building--(i) Construction. (a) Processing buildings
shall be of fire-resistance or noncombustible construction, except heavy
timber construction with load-bearing walls may be permitted for plants
utilizing only stable Class II or Class III liquids. Except as provided
in paragraph (h)(2)(ii) of this section or in the case of explosion
resistant walls used in conjunction with explosion relieving facilities,
see paragraph (h)(3)(iv) of this section, load-bearing walls are
prohibited. Buildings shall be without basements or covered pits.
(b) Areas shall have adequate exit facilities arranged to prevent
occupants from being trapped in the event of fire. Exits shall not be
exposed by the drainage facilities described in paragraph (h)(ii) of
this section.
(ii) Drainage. (a) Emergency drainage systems shall be provided to
direct flammable or combustible liquid leakage and fire protection water
to a safe location. This may require curbs, scuppers, or special
drainage systems to control the spread of fire, see paragraph
(b)(2)(vii)(b) of this section.
[[Page 267]]
(b) Emergency drainage systems, if connected to public sewers or
discharged into public waterways, shall be equipped with traps or
separators.
(iii) Ventilation. (a) Enclosed processing buildings shall be
ventilated at a rate of not less than 1 cubic foot per minute per square
foot of solid floor area. This shall be accomplished by natural or
mechanical ventilation with discharge or exhaust to a safe location
outside of the building. Provisions shall be made for introduction of
makeup air in such a manner as not to short circuit the ventilation.
Ventilation shall be arranged to include all floor areas or pits where
flammable vapors may collect.
(b) Equipment used in a building and the ventilation of the building
shall be designed so as to limit flammable vapor-air mixtures under
normal operating conditions to the interior of equipment, and to not
more than 5 feet from equipment which exposes Class I liquids to the
air. Examples of such equipment are dispensing stations, open
centrifuges, plate and frame filters, open vacuum filters, and surfaces
of open equipment.
(iv) Explosion relief. Areas where Class IA or unstable liquids are
processed shall have explosion venting through one or more of the
following methods:
(a) Open air construction.
(b) Lightweight walls and roof.
(c) Lightweight wall panels and roof hatches.
(d) Windows of explosion venting type.
(4) Liquid handling--(i) Storage. (a) The storage of flammable or
combustible liquids in tanks shall be in accordance with the applicable
provisions of paragraph (b) of this section.
(b) If the storage of flammable or combustible liquids in outside
aboveground or underground tanks is not practical because of temperature
or production considerations, tanks may be permitted inside of buildings
or structures in accordance with the applicable provisions of paragraph
(b) of this section.
(c) Storage tanks inside of buildings shall be permitted only in
areas at or above grade which have adequate drainage and are separated
from the processing area by construction having a fire resistance rating
of at least 2 hours.
(d) The storage of flammable or combustible liquids in containers
shall be in accordance with the applicable provisions of paragraph (d)
of this section.
(ii) Piping, valves, and fittings. (a) Piping, valves, and fittings
shall be in accordance with paragraph (c) of this section.
(b) Approved flexible connectors may be used where vibration exists
or where frequent movement is necessary. Approved hose may be used at
transfer stations.
(c) Piping containing flammable or combustible liquids shall be
identified.
(iii) Transfer. (a) The transfer of large quantities of flammable or
combustible liquids shall be through piping by means of pumps or water
displacement. Except as required in process equipment, gravity flow
shall not be used. The use of compressed air as a transferring medium is
prohibited.
(b) Positive displacement pumps shall be provided with pressure
relief discharging back to the tank or to pump suction.
(iv) Equipment. (a) Equipment shall be designed and arranged to
prevent the unintentional escape of liquids and vapors and to minimize
the quantity escaping in the event of accidental release.
(b) Where the vapor space of equipment is usually within the
flammable range, the probability of explosion damage to the equipment
can be limited by inerting, by providing an explosion suppression
system, or by designing the equipment to contain the peak explosion
pressure which may be modified by explosion relief. Where the special
hazards of operation, sources of ignition, or exposures indicate a need,
consideration shall be given to providing protection by one or more of
the above means.
(5) Tank vehicle and tank car loading and unloading. Tank vehicle
and tank car loading or unloading facilities shall be separated from
aboveground tanks, warehouses, other plant buildings, or nearest line of
adjoining property which may be built upon by a distance of 25 feet for
Class I liquids and 15 feet for Class II and Class III liquids measured
from the nearest position of any
[[Page 268]]
fill stem. Buildings for pumps or shelters for personnel may be a part
of the facility. Operations of the facility shall comply with the
appropriate portions of paragraph (f)(3) of this section.
(6) Fire control--(i) Portable extinguishers. Approved portable fire
extinguishers of appropriate size, type, and number shall be provided.
(ii) Other controls. Where the special hazards of operation or
exposure indicate a need, the following fire control provision shall be
provided.
(a) A reliable water supply shall be available in pressure and
quantity adequate to meet the probable fire demands.
(b) Hydrants shall be provided in accordance with accepted good
practice.
(c) Hose connected to a source of water shall be installed so that
all vessels, pumps, and other equipment containing flammable or
combustible liquids can be reached with at least one hose stream.
Nozzles that are capable of discharging a water spray shall be provided.
(d) Processing plants shall be protected by an approved automatic
sprinkler system or equivalent extinguishing system. If special
extinguishing systems including but not limited to those employing foam,
carbon dioxide, or dry chemical are provided, approved equipment shall
be used and installed in an approved manner.
(iii) Alarm systems. An approved means for prompt notification of
fire to those within the plant and any public fire department available
shall be provided. It may be advisable to connect the plant system with
the public system where public fire alarm system is available.
(iv) Maintenance. All plant fire protection facilities shall be
adequately maintained and periodically inspected and tested to make sure
they are always in satisfactory operating condition and that they will
serve their purpose in time of emergency.
(7) Sources of ignition--(i) General. (a) Precautions shall be taken
to prevent the ignition of flammable vapors. Sources of ignition include
but are not limited to 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.
(b) Class I liquids shall not be dispensed into containers unless
the nozzle and container are electrically interconnected. Where the
metallic floorplate on which the container stands while filling is
electrically connected to the fill stem or where the fill stem is bonded
to the container during filling operations by means of a bond wire, the
provisions of this section shall be deemed to have been complied with.
(ii) Maintenance and repair. (a) When necessary to do maintenance
work in a flammable or combustible liquid processing area, the work
shall be authorized by a responsible representative of the employer.
(b) Hot work, such as welding or cutting operations, use of spark-
producing power tools, and chipping operations shall be permitted only
under supervision of an individual in responsible charge who shall make
an inspection of the area to be sure that it is safe for the work to be
done and that safe procedures will be followed for the work specified.
(iii) Electrical. (a) All electric wiring and equipment shall be
installed in accordance with subpart S of this part.
(b) Locations where flammable vapor-air mixtures may exist under
normal operations shall be classified Class I, Division 1 according to
the requirements of subpart S of this part. For those pieces of
equipment installed in accordance with paragraph (h)(3)(iii)(b) of this
section, the Division 1 area shall extend 5 feet in all directions from
all points of vapor liberation. All areas within pits shall be
classified Division 1 if any part of the pit is within a Division 1 or 2
classified area, unless the pit is provided with mechanical ventilation.
(c) Locations where flammable vapor-air mixtures may exist under
abnormal conditions and for a distance beyond Division 1 locations shall
be classified Division 2 according to the requirements of subpart S of
this part. These locations include an area within 20 feet horizontally,
3 feet vertically beyond a Division 1 area, and up to 3 feet above
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floor or grade level within 25 feet, if indoors, or 10 feet if outdoors,
from any pump, bleeder, withdrawal fitting, meter, or similar device
handling Class I liquids. Pits provided with adequate mechanical
ventilation within a Division 1 or 2 area shall be classified Division
2. If Class II or Class III liquids only are handled, then ordinary
electrical equipment is satisfactory though care shall be used in
locating electrical apparatus to prevent hot metal from falling into
open equipment.
(d) Where the provisions of paragraphs (h)(7)(iii) (a), (b), and (c)
of this section require the installation of explosion-proof equipment,
ordinary electrical equipment including switchgear may be used if
installed in a room or enclosure which is maintained under positive
pressure with respect to the hazardous area. Ventilation makeup air
shall be uncontaminated by flammable vapors.
(8) Housekeeping--(i) General. Maintenance and operating practices
shall be in accordance with established procedures which will tend to
control leakage and prevent the accidental escape of flammable or
combustible liquids. Spills shall be cleaned up promptly.
(ii) Access. Adequate aisles shall be maintained for unobstructed
movement of personnel and so that fire protection equipment can be
brought to bear on any part of the processing equipment.
(iii) Waste and residues. Combustible waste material and residues in
a building or operating area shall be kept to a minimum, stored in
closed metal waste cans, and disposed of daily.
(iv) Clear zone. Ground area around buildings and operating areas
shall be kept free of tall grass, weeds, trash, or other combustible
materials.
(i) Refineries, chemical plants, and distilleries--(1) Storage
tanks. Flammable or combustible liquids shall be stored in tanks, in
containers, or in portable tanks. Tanks shall be installed in accordance
with paragraph (b) of this section. Tanks for the storage of flammable
or combustible liquids in tank farms and in locations other than process
areas shall be located in accordance with paragraph (b)(2) (i) and (ii)
of this section.
(2) Wharves. Wharves handling flammable or combustible liquids shall
be in accordance with paragraph (f)(4) of this section.
(3) Fired and unfired pressure vessels--(i) Fired vessels. Fired
pressure vessels shall be constructed in accordance with the Code for
Fired Pressure Vessels, Section I of the ASME Boiler and Pressure Vessel
Code--1968.
(ii) Unfired vessels shall be constructed in accordance with the
Code for Unfired Pressure Vessels, Section VIII of the ASME Boiler and
Pressure Vessel Code--1968.
(4) Location of process units. Process units shall be located so
that they are accessible from at least one side for the purpose of fire
control.
(5) Fire control--(i) Portable equipment. Portable fire
extinguishment and control equipment shall be provided in such
quantities and types as are needed for the special hazards of operation
and storage.
(ii) Water supply. Water shall be available in volume and at
adequate pressure to supply water hose streams, foam producing
equipment, automatic sprinklers, or water spray systems as the need is
indicated by the special hazards of operation and storage.
(iii) Special equipment. Special extinguishing equipment such as
that utilizing foam, inert gas, or dry chemical shall be provided as the
need is indicated by the special hazards of operation and storage.
(j) Scope. This section applies to the handling, storage, and use of
flammable and combustible liquids with a flashpoint below 200 [deg]F.
This section does not apply to:
(1) Bulk transportation of flammable and combustible liquids;
(2) Storage, handling, and use of fuel oil tanks and containers
connected with oil burning equipment;
(3) Storage of flammable and combustible liquids on farms;
(4) Liquids without flashpoints that may be flammable under some
conditions, such as certain halogenated hydrocarbons and mixtures
containing halogenated hydrocarbons;
(5) Mists, sprays, or foams, except flammable aerosols covered in
paragraph (d) of this section; or
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(6) Installations made in accordance with requirements of the
following standards that are incorporated by reference as specified in
Sec. 1910.6:
(i) National Fire Protection Association Standard for Drycleaning
Plants, NFPA No. 32-1970;
(ii) National Fire Protection Association Standard for the
Manufacture of Organic Coatings, NFPA No. 35-1970;
(iii) National Fire Protection Association Standard for Solvent
Extraction Plants, NFPA No. 36-1967; or
(iv) National Fire Protection Association Standard for the
Installation and Use of Stationary Combustion Engines and Gas Turbines,
NFPA No. 37-1970.
[39 FR 23502, June 27, 1974, as amended at 40 FR 3982, Jan. 27, 1975; 40
FR 23743, June 2, 1975; 43 FR 49746, Oct. 24, 1978; 43 FR 51759, Nov. 7,
1978; 47 FR 39164, Sept. 7, 1982; 51 FR 34560, Sept. 29, 1986; 53 FR
12121, Apr. 12, 1988; 55 FR 32015, Aug. 6, 1990; 61 FR 9237, Mar. 7,
1996; 70 FR 53929, Sept. 13, 2005]
