- Part Number:1910
- Part Number Title:Occupational Safety and Health Standards
- Subpart:1910 Subpart H
- Subpart Title:Hazardous Materials
- Standard Number:
- Title:Flammable liquids.
- GPO Source:
"Definitions." As used in this section:
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.
Listed see "approved" in 1910.106(a)(35).
"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).
"Viscous" means a viscosity of 45 SUS or more.
"Tank storage" -
"Design and construction of tanks" -
"Materials."
"Fabrication."
"Atmospheric tanks."
"Low pressure tanks."
This paragraph may be used for operating pressures not exceeding 1 p.s.i.g.
"Pressure vessels."
"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.
"Installation of outside above ground tanks."
"Spacing (shell-to-shell) between above ground tanks."
"Normal venting for above ground tanks."
"Emergency relief venting for fire exposure for above ground tanks."
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 °F.]
| Square feet | CFH | Square feet | CFH | Square 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 |
CFH = 1,107A0.82
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 = 21,000A0.82.
V = 1337 divided by L square root of 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.
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.
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.
"Vent piping for above ground tanks."
"Drainage, dikes, and walls for above ground tanks" -
"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.
"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:
"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:
"Tank openings other than vents for above ground tanks."
"Installation of underground tanks" -
"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 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.
"Corrosion protection." Corrosion protection for the tank and its piping shall be provided by one or more of the following methods:
"Vents."
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
[14.7 psia and 60 °F.]
| Maximum flow GPM | Pipe length1 | ||
|---|---|---|---|
| 50 feet | 100 feet | 200 feet | |
| Inches | Inches | Inches | |
| 100 | 1¼ | 1¼ | 1¼ |
| 200 | 1¼ | 1¼ | 1¼ |
| 300 | 1¼ | 1¼ | 1½ |
| 400 | 1¼ | 1½ | 2 |
| 500 | 1½ | 1½ | 2 |
| 600 | 1½ | 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.
"Tank openings other than vents."
"Installation of tanks inside of buildings" -
"Location." Tanks shall not be permitted inside of buildings except as provided in paragraphs (e), (g), (h), or (i) of this section.
"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.
"Vent piping." Vent piping shall be constructed in accordance with paragraph (c) of this section.
"Tank openings other than vents."
"Supports, foundations, and anchorage for all tank locations" -
"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.
"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.
"Spheres." The design of the supporting structure for tanks such as spheres shall receive special engineering consideration.
"Load distribution." Every tank shall be so supported as to prevent the excessive concentration of loads on the supporting portion of the shell.
"Foundations." Tanks shall rest on the ground or on foundations made of concrete, masonry, piling, or steel. Tank foundations shall be designed to minimize the possibility of uneven settling of the tank and to minimize corrosion in any part of the tank resting on the foundation.
"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.
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.
"Earthquake areas." In areas subject to earthquakes, the tank supports and connections shall be designed to resist damage as a result of such shocks.
"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.
"Testing" -
"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.
"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 tested hydrostatically to a pressure equal to the static head thus imposed.
"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.
"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.
"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.
"Piping, valves, and fittings" -
"General" -
"Design." The design (including selection of materials) fabrication, assembly, test, and inspection of piping systems containing flammable liquids shall be suitable for the expected working pressures and structural stresses. 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.
"Exceptions." This paragraph does not apply to any of the following:
"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.
"Materials for piping, valves, and fittings" -
"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.
"Exceptions." Materials other than steel, nodular iron, or malleable iron may be used underground, or if required by the properties of the flammable 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.
"Linings." Piping, valves, and fittings may have combustible or noncombustible linings.
"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.
"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 persons, important buildings or structures, and could be readily controlled by remote valves.
"Supports." Piping systems shall be substantially supported and protected against physical damage and excessive stresses arising from settlement, vibration, expansion, or contraction.
"Protection against corrosion." All piping for flammable liquids, both above ground and underground, where subject to external corrosion, shall be painted or otherwise protected.
"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.
"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.
"Container and portable tank storage" -
"Scope" -
"General." This paragraph shall apply only to the storage of flammable liquids in drums or other containers (including flammable aerosols) not exceeding 60 gallons individual capacity and those portable tanks not exceeding 660 gallons individual capacity.
"Exceptions." This paragraph shall not apply to the following:
"Design, construction, and capacity of containers" -
"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.
"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.
The containers are intended for direct export outside the United States.
Table H-12--Maximum Allowable Size of Containers and Portable Tanks for Flammable Liquids
| Container type | Category 1 | Category 2 | Category 3 | Category 4 |
|---|---|---|---|---|
| Glass or approved plastic | 1 pt | 1 qt | 1 gal | 1 gal. |
| Metal (other than DOT drums) | 1 gal | 5 gal | 5 gal | 5 gal. |
| Safety cans | 2 gal | 5 gal | 5 gal | 5 gal. |
| Metal drums (DOT specifications) | 60 gal | 60 gal | 60 gal | 60 gal. |
| Approved portable tanks | 660 gal | 660 gal | 660 gal | 660 gal. |
Note: Container exemptions: (a) Medicines, beverages, foodstuffs, cosmetics, and other common consumer items, when packaged according to commonly accepted practices, shall be exempt from the requirements of 1910.106(d)(2)(i) and (ii).
"Design, construction, and capacity of storage cabinets" -
"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."
"Design and construction of inside storage rooms" -
"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 at least 1 inch nominal thickness may be used for shelving, racks, dunnage, scuffboards, floor overlay, and similar installations.
"Rating and capacity." Storage in inside storage rooms shall comply with Table H-13.
Table H-13—Storage in Inside Rooms
| Fire protection1 provided | Fire resistance | Maximum size | Total allowable quantities (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.
"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.
"Storage inside building" -
"Egress." flammable 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.
"Containers." The storage of flammable liquids in containers or portable tanks shall comply with subdivisions (iii) through (v) of this subparagraph.
"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.
"Mercantile occupancies and other retail stores."
"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 liquids may be stored in the same area.
TABLE H-14 - INDOOR CONTAINER STORAGE
| Category liquid | Storage level | Gallons | |
|---|---|---|---|
| Protected storage maximum per pile | Unprotected storage maximum per pile | ||
| 1 ..... | Ground and upper floors..... | 2,750 | 660 |
| (50) | (12) | ||
| Basement.................... | Not permitted | Not permitted | |
| 2 ..... | Ground and upper floors..... | 5,500 | 1,375 |
| (100) | (25) | ||
| Basement.................... | Not permitted | Not permitted | |
| 3 ..... | Ground and upper floors..... | 16,500 | 4,125 |
| FP>100F | (300) | (75) | |
| Basement.................... | Not permitted | Not permitted | |
| 3 .... | Ground and upper floors..... | 16,500 | 4,125 |
| FP≥100F | (300) | (75) | |
| Basement.................... | Not permitted | Not permitted | |
| (100) | |||
| 4 ... | Ground and upper floors..... | 55,000 | 13,750 |
| (1,000) | (250) | ||
| Basement.................... | 8,250 | Not permitted | |
| (450) |
NOTE 1: When 2 or more categories 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.
NOTE 4: FP means Flashpoint. (Number in parenthesis indicate corresponding number of 55-gal. drums.)
TABLE H-15 - INDOOR PORTABLE TANK STORAGE
| Category | Storage level | Gallons | |
|---|---|---|---|
| Protected storage maximum per pile | Unprotected storage maximum per pile | ||
| 1 .... | Ground and upper floors..... | Not permitted | Not permitted |
| Basement.................... | Not permitted | Not permitted | |
| 2 ..... | Ground and upper floors..... | 20,000 | 2,000 |
| Basement.................... | Not permitted | Not permitted | |
| 3 ..... | Ground and upper floors..... | 40,000 | 5,500 |
| FP>100F | Basement.................... | Not permitted | Not permitted |
| 3 .... | Ground and upper floors..... | 40,000 | 5,500 |
| FP≥100F | Basement.................... | 20,000 | Not permitted |
| 4 ... | Ground and upper floors..... | 60,000 | 22,000 |
| Basement.................... | 20,000 | Not permitted |
NOTE 1: When 1 or more categories 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.
NOTE 4: FP means Flashpoint.
"Flammable liquid warehouses or storage buildings."
"Storage outside buildings" -
"General." Storage outside buildings shall be in accordance with Table H-16 or H-17, and subdivisions (ii) and (iv) of this subparagraph.
TABLE H-16 - OUTDOOR CONTAINER STORAGE
| 1-Category | 2-Maximum per pile | 3-Distance between piles | 4-Distance to property line that can be built upon | 5-Distance to street, alley, public way |
|---|---|---|---|---|
| gallons | feet | feet | feet | |
| 1 ........ | 1,100 | 5 | 20 | 10 |
| 2 ........ | 2,200 | 5 | 20 | 10 |
| 3 FP<100F. | 4,400 | 5 | 20 | 10 |
| 3 FP≥100F. | 8,800 | 5 | 20 | 10 |
| 4 ........ | 22,000 | 5 | 20 | 10 |
NOTE 1: When 2 or more categories 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.
NOTE 5: FP means Flashpoint.
"Maximum storage." A maximum of 1,100 gallons of flammable 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.
"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 liquids. Drains shall terminate at a safe location and shall be accessible to operation under fire conditions.
"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.
"Fire control" -
"Extinguishers." Suitable fire control devices, such as small hose or portable fire extinguishers, shall be available at locations where flammable liquids are stored.
TABLE H-17 - OUTDOOR PORTABLE TANK STORAGE
___________________________________________________________________
| | | |
| | | 4-Distance |
| | 3-Distance | to property | 5-Distance
1-Category| 2-Maximum | between | line that | to street,
| per pile | piles | can be built | alley, public
| | | upon | way
___________|____________|____________|______________|______________
| | | |
| gallons | feet | feet | feet
|____________|____________|______________|______________
| | | |
1 ........| 2,200 | 5 | 20 | 10
2 ........| 4,400 | 5 | 20 | 10
3 FP<100F.| 8,800 | 5 | 20 | 10
3 FP≥100F.| 17,600 | 5 | 10 | 5
4 ........| 44,000 | 5 | 10 | 5
___________|____________|____________|______________|______________
NOTE 1: When 2 or more categories 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.
NOTE 5: FP means flashpoint.
"Sprinklers." When sprinklers are provided, they shall be installed in accordance with 1910.159.
"Open flames and smoking." Open flames and smoking shall not be permitted in flammable liquid storage areas.
"Water reactive materials." Materials which will react with water shall not be stored in the same room with flammable liquids.
"Industrial plants" -
"Scope" -
"Application." This paragraph shall apply to those industrial plants where:
"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.
"Incidental storage or use of flammable liquids" -
"Application." This subparagraph shall be applicable to those portions of an industrial plant where the use and handling of flammable liquids is only incidental to the principal business, such as automobile assembly, construction of electronic equipment, furniture manufacturing, or other similar activities.
"Containers." flammable liquids shall be stored in tanks or closed containers.
660 gallons of Category 2, 3, or 4 flammable liquids in a single portable tank.
"Separation and protection." Areas in which flammable 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.
"Handling liquids at point of final use."
"Unit physical operations" -
"Application." This subparagraph shall be applicable in those portions of industrial plants where flammable 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.
"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.
"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.
"Drainage."
"Ventilation."
"Storage and handling." The storage, transfer, and handling of liquid shall comply with paragraph (h)(4) of this section.
"Tank vehicle and tank car loading and unloading."
"Fire control" -
"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.
"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.
"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.
"Special hazards." Where the need is indicated by special hazards of operation, flammable liquid processing equipment, major piping, and supporting steel shall be protected by approved water spray systems, deluge systems, approved fire-resistant coatings, insulation, or any combination of these.
"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.
"Sources of ignition" -
"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.
"Electrical" -
"Equipment."
"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.
"Housekeeping" -
"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 liquids. Spills shall be cleaned up promptly.
"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 liquid storage, use, or any unit physical operation.
"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.
"Clear zone." Ground area around buildings and unit operating areas shall be kept free of weeds, trash, or other unnecessary combustible materials.
"Bulk plants" -
"Storage" -
"Piling containers." Containers of flammable 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.
"Buildings" -
"Exits." Rooms in which flammable liquids are stored or handled by pumps shall have exit facilities arranged to prevent occupants from being trapped in the event of fire.
"Ventilation."
"Loading and unloading facilities" -
"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.
"Static protection."
"Wharves" -
"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 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.
"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.
"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.
"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.
"Piping and fittings." Piping, valves, and fittings shall be in accordance with paragraph (c) of this section, with the following exceptions and additions:
"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.
"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.
"Electrical equipment" -
"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.
"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.
Sources of ignition. Category 1 or 2 flammable liquids, or Category 3 flammable liquids with a flashpoint below 100 °F (37.8 °C), 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.
"Drainage and waste disposal." Provision shall be made to prevent flammable 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 liquids might enter shall be provided with separator boxes or other approved means whereby such entry is precluded. Crankcase drainings and flammable 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.
"Service stations" -
"Storage and handling" -
"General provisions."
[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 | 1 | Within 3 feet of open end
dome with atmospheric | | of vent, extending in
venting. | | all directions.
| 2 | 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.
Loading through closed | 2 | Within 3 feet of point of
dome with vapor | | connection of both fill
recovery. | | 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
unloading. | | all 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.
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 | 2 | Entire area within pit if any
ventilation.............. | | part is within a Division
| | 1 or 2 classified area.
Containing valves, | 2 | Entire pit.
fittings 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 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...... | 2 | floor level.
| | 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
separator, impounding | | ditch, separator or basin.
basins. | | Also up to 18 inches above
| | grade within 15 feet
| | horizontally from any edge.
Garages for other than | (2) | If there is any opening to
tank 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 area, the
| | entire room shall be
| | classified the same as if
| | the wall, curb or
| | partition did not exist.
Office and rest rooms.... | (2) |
____________________________|________|______________________________
Footnote(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.
Footnote(2) Ordinary.
"Special enclosures."
"Inside buildings."
"Dispensing systems" -
"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.
"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.
"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 emergency.
"Dispensing units."
"Remote pumping systems."
"Delivery nozzles."
"Marine service stations" -
"Dispensing."
"Tanks and pumps."
"Piping."
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.
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 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 the pump.
| 2 | Within 3 feet of any edge of the
| | pump, extending in all
| | directions. Also up to 18
| | inches above grade level within
| | 10 feet horizontally from any
| | edge of the pump.
Remote pump - Indoor .| 1 | Entire area within any pit.
| 2 | Within 5 feet of any edg 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 | |
Liquids with a | |
flashpoint below | |
100 °F (37.8 °C)(1)...| 2 | Within 3 feet of any fill or
| | dispensing point, extending in
| | all directions.
Special enclosure | |
inside building per | 1 | Entire enclosure.
1910.106(f)(1)(ii). | |
Sales, storage and | |
rest rooms..........| (2) | If there is any opening to these
| | rooms within the extent of a
| | Division 1 area, the entire
| | room shall be classified as
| | Division 1.
_______________________|________|________________________________________
Footnote (1) Category 1 or 2 flammable liquids, or for Category 3 flammable
liquids with a flashpoint below 100 °F (37.8 °C).
Footnote (2) Ordinary
"Electrical equipment" -
"Heating equipment" -
"Conformance." Heating equipment shall be installed as provided in paragraphs (g)(6)(ii) through (v) of this section.
"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.
"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.
"Electric heat." Electrical heating equipment shall conform to paragraph (g)(5) of this section.
"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 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.
"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.
"Processing plants" -
"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.
"Location" -
"Classification." The location of each processing vessel shall be based upon its flammable liquid capacity.
"Processing building" -
"Construction."
"Drainage."
"Ventilation."
"Liquid handling" -
"Storage."
"Piping, valves, and fittings."
"Transfer."
"Equipment."
"Fire control" -
"Portable extinguishers." Approved portable fire extinguishers of appropriate size, type, and number shall be provided.
"Other controls." Where the special hazards of operation or exposure indicate a need, the following fire control provision shall be provided.
"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.
"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.
"Sources of ignition" -
"General."
"Maintenance and repair."
"Electrical."
"Housekeeping" -
"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 liquids. Spills shall be cleaned up promptly.
"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.
"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.
"Clear zone." Ground area around buildings and operating areas shall be kept free of tall grass, weeds, trash, or other combustible materials.
"Refineries, chemical plants, and distilleries" -
"Storage tanks." flammable 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 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.
"Wharves." Wharves handling flammable liquids shall be in accordance with paragraph (f)(4) of this section.
"Fired and unfired pressure vessels" -
"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.
"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.
"Fire control" -
"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.
"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.
"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.
[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 9227, March 7, 1996; 70 FR 53929, Sept. 13, 2005; 77 FR 17766, March 26, 2012; 81 FR 10490-10491, March 1, 2016]