### 288 29 CFR Ch. XVII (7–1–15 Edition) § 1910.108

this equipment in the coating area shall not exceed 150 ° F. The high voltage circuits shall be so designed as tonot produce a spark of sufficient intensity to ignite any powder-air mixtures nor result in appreciable shock hazardupon coming in contact with a grounded object under normal operating conditions.

(ii) Transformers, powerpacks, control apparatus, and all other electricalportions of the equipment, with the exception of the charging electrodes and their connections to the power supply shall be located outside of the powdercoating area or shall otherwise conform to the requirements of paragraph (l)(1) of this section.

(iii) All electrically conductive objects within the charging influence of the electrodes shall be adequatelygrounded. The powder coating equipment shall carry a prominent, permanently installed warning regarding the necessity for grounding these objects.

(iv) Objects being coated shall bemaintained in contact with the conveyor or other support in order to insure proper grounding. Hangers shall be regularly cleaned to insure effective contact and areas of contact shall besharp points or knife edges where possible.

(v) The electrical equipment shall beso interlocked with the ventilation system that the equipment cannot be operated unless the ventilation fans are in operation.

(m) Organic peroxides and dual component coatings—(1) Conformance. All spraying operations involving the use of organic peroxides and other dual component coatings shall be conducted in approved sprinklered spray boothsmeeting the requirements of this section.

(2) Smoking. Smoking shall be prohibited and ‘‘No Smoking’’ signs shall beprominently displayed and only nonsparking tools shall be used in any area where organic peroxides are stored, mixed or applied.

(n) Scope. This section applies to flammable and combustible finishing materials when applied as a spray by compressed air, ‘‘airless’’ or ‘‘hydraulic atomization,’’ steam, electrostaticmethods, or by any other means in continuous or intermittent processes. The section also covers the application of combustible powders by powder spray guns, electrostatic powder spray guns, fluidized beds, or electrostatic fluidized beds. The section does not apply to outdoor spray application of buildings, tanks, or other similar structures, nor to small portable spraying apparatusnot used repeatedly in the same location.

[39 FR 23502, June 27, 1974, as amended at 45 FR 60704, Sept. 12, 1980; 49 FR 5322, Feb. 10, 1984; 53 FR 12121, Apr. 12, 1988; 61 FR 9237, Mar. 7, 1996; 72 FR 71069, Dec. 14, 2007; 77 FR 17776, Mar. 26, 2012]

§ 1910.108 [Reserved]

§ 1910.109 Explosives and blasting agents.

(a) Definitions applicable to this section—(1) Blasting agent. Blastingagent—any material or mixture, consisting of a fuel and oxidizer, intended for blasting, not otherwise classified as an explosive and in which none of theingredients are classified as an explosive, provided that the finished product, as mixed and packaged for use or shipment, cannot be detonated by means of a No. 8 test blasting cap when
unconfined.

(2) Explosive-actuated power devices. Explosive-actuated power device—any tool or special mechanized device which is actuated by explosives, but not including propellant-actuatedpower devices. Examples of explosiveactuated power devices are jet tappers and jet perforators.

(3) Explosive. Explosive—any chemical compound, mixture, or device, the primary or common purpose of which isto function by explosion, i.e., with substantially instantaneous release of gasand heat, unless such compound, mixture, or device is otherwise specifically classified by the U.S. Department of Transportation; see 49 CFR chapter I. The term ‘‘explosives’’ shall include all material which is classified as Class A, Class B, and Class C explosives by the U.S. Department of Transportation,and includes, but is not limited to dynamite, black powder, pellet powders, initiating explosives, blasting caps, electric blasting caps, safety fuse, fuse lighters, fuse igniters, squibs, cordeau


### 289 Occupational Safety and Health Admin., Labor § 1910.109

detonant fuse, instantaneous fuse, igniter cord, igniters, small arms ammunition, small arms ammunition primers, smokeless propellant, cartridges for propellant-actuated power devices, and cartridges for industrial guns.Commercial explosives are those explosives which are intended to be used in commercial or industrial operations.

N OTE 1: Classification of explosives is described by the U.S. Department of Transportation as follows (see 49 CFR chapter I):

(i) Class A explosives. Possessing, detonating, or otherwise maximum hazard; such as dynamite, nitroglycerin, picric acid, lead azide, fulminate of mercury, black powder, blasting caps, and detonating primers.

(ii) Class B explosives. Possessing flammable hazard, such as propellant explosives (including some smokelesspropellants), photographic flash powders, and some special fireworks.

(iii) Class C explosives. Includes certain types of manufactured articleswhich contain Class A or Class B explosives, or both, as components but in restricted quantities.

(iv) Forbidden or not acceptable explosives. Explosives which are forbidden or not acceptable for transportation by common carriers by rail freight, railexpress, highway, or water in accordance with the regulations of the U.S. Department of Transportation, 49 CFR chapter I.

(4) Highway. Highway—any public street, public alley, or public road.

(5) [Reserved] (6) Magazine. Magazine—any building or structure, other than an explosives manufacturing building, used for the storage of explosives.

(7) Motor vehicle. Motor vehicle—any self-propelled vehicle, truck, tractor, semitrailer, or truck-full trailers used for the transportation of freight over public highways.

(8) Propellant-actuated power devices. Propellant-actuated power devices— any tool or special mechanized deviceor gas generator system which is actuated by a smokeless propellant or which releases and directs work through a smokeless propellant charge.

(9) [Reserved] (10) Pyrotechnics. Pyrotechnics—any combustible or explosive compositions or manufactured articles designed and prepared for the purpose of producing audible or visible effects which are commonly referred to as fireworks.

(11) [Reserved] (12) Semiconductive hose. Semiconductive hose—a hose with an electrical resistance high enough to limit flow of stray electric currents tosafe levels, yet not so high as to prevent drainage of static electric charges to ground; hose of not more than 2 megohms resistance over its entire length and of not less than 5,000 ohms per foot meets the requirement.

(13) Small arms ammunition. Small arms ammunition—any shotgun, rifle,pistol, or revolver cartridge, and cartridges for propellant-actuated powerdevices and industrial guns. Militarytype ammunition containing explosivebursting charges, incendiary, tracer, spotting, or pyrotechnic projectiles is excluded from this definition.

(14) Small arms ammunition primers. Small arms ammunition primers— small percussion-sensitive explosivecharges, encased in a cup, used to ignite propellant powder.

(15) Smokeless propellants. Smokelesspropellants—solid propellants, commonly called smokeless powders in the trade, used in small arms ammunition, cannon, rockets, propellant-actuated power devices, etc.

(16) Special industrial explosives devices. Special industrial explosives devices—explosive-actuated power devices and propellant-actuated power devices.

(17) Special industrial explosives materials. Special industrial explosives materials—shaped materials and sheet forms and various other extrusions,pellets, and packages of high explosives, which include dynamite, trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), hexahydro-1,3,5- trinitro-s-triazine (RDX), and othersimilar compounds used for high-energy-rate forming, expanding, and shaping in metal fabrication, and for dismemberment and quick reduction of scrap metal.

(18) Water gels or slurry explosives.These comprise a wide variety of materials used for blasting. They all contain substantial proportions of water and high proportions of ammonium nitrate, some of which is in solution in the


### 290 29 CFR Ch. XVII (7–1–15 Edition) § 1910.109

water. Two broad classes of water gels are (i) those which are sensitized by a material classed as an explosive, such as TNT or smokeless powder, (ii) those which contain no ingredient classified as an explosive; these are sensitized
with metals such as aluminum or with other fuels. Water gels may be premixed at an explosives plant or mixed at the site immediately before delivery into the borehole.

(19) DOT specifications. Regulations ofthe Department of Transportation published in 49 CFR chapter I.

(b) Miscellaneous provisions—(1) General hazard. No person shall store, handle, or transport explosives or blasting agents when such storage, handling, and transportation of explosives or blasting agents constitutes an undue
hazard to life.

(2) [Reserved] (c) Storage of explosives—(1) General provisions. (i) All Class A, Class B, ClassC explosives, and special industrial explosives, and any newly developed and unclassified explosives, shall be kept inmagazines which meet the requirements of this paragraph.

(ii) Blasting caps, electric blasting caps, detonating primers, and primed cartridges shall not be stored in the same magazine with other explosives.

(iii) Ground around magazines shallslope away for drainage. The land surrounding magazines shall be kept clear of brush, dried grass, leaves, and other
materials for a distance of at least 25
feet.

(iv) Magazines as required by this paragraph shall be of two classes; namely, Class I magazines, and Class II magazines.

(v) Class I magazines shall be required where the quantity of explosives stored is more than 50 pounds. Class II magazines may be used where the quantity of explosives stored is 50 pounds or less.

(vi) Class I magazines shall be located away from other magazines in conformity with Table H–21. TABLE H–21—A MERICAN TABLE OF D ISTANCES

FOR S TORAGE OF E XPLOSIVES 1 5

[As revised and approved by the Institute of Makers of Explosives, June 5, 1964]

Explosives Distances in feet when storage isbarricaded: Separation of magazines Pounds over Pounds not over

2 5 6
5 10 8
10 20 10
20 30 11
30 40 12
40 50 14
50 75 15
75 100 16
100 125 18
125 150 19
150 200 21
200 250 23
250 300 24
300 400 27
400 500 29
500 600 31
600 700 32
700 800 33
800 900 35 900 1,000 36 1,000 1,200 39 1,200 1,400 41 1,400 1,600 43 1,600 1,800 44 1,800 2,000 45 2,000 2,500 49 2,500 3,000 52 3,000 4,000 58 4,000 5,000 61 5,000 6,000 65 6,000 7,000 68 7,000 8,000 72 8,000 9,000 75 9,000 10,000 78 10,000 12,000 82 12,000 14,000 87 14,000 16,000 90 16,000 18,000 94 18,000 20,000 98 20,000 25,000 105 25,000 30,000 112 30,000 35,000 119 35,000 40,000 124 40,000 45,000 129 45,000 50,000 135 50,000 55,000 140 55,000 60,000 145 60,000 65,000 150 65,000 70,000 155 70,000 75,000 160 75,000 80,000 165 80,000 85,000 170 85,000 90,000 175 90,000 95,000 180 95,000 100,000 185 100,000 110,000 195 110,000 120,000 205 120,000 130,000 215 130,000 140,000 225 140,000 150,000 235 150,000 160,000 245 160,000 170,000 255 170,000 180,000 265 180,000 190,000 275 190,000 200,000 285


### 291 Occupational Safety and Health Admin., Labor § 1910.109

TABLE H–21—A MERICAN TABLE OF D ISTANCES

FOR S TORAGE OF E XPLOSIVES 1 5—Continued

[As revised and approved by the Institute of Makers of Explosives, June 5, 1964]

Explosives Distances in feet when storage isbarricaded: Separation of magazines Pounds over Pounds not over

200,000 210,000 295 210,000 230,000 315 230,000 250,000 335 250,000 275,000 360 275,000 300,000 385

1 ‘‘Natural barricade’’ means natural features of the ground,such as hills, or timber of sufficient density that the surrounding exposures which require protection cannot be seen from the magazine when the trees are bare of leaves.

2 ‘‘Artificial barricade’’ means an artificial mound or revetted wall of earth of a minimum thickness of three feet.

3 ‘‘Barricaded’’ means that a building containing explosives is effectually screened from a magazine, building, railway, orhighway, either by a natural barricade, or by an artificial barricade of such height that a straight line from the top of any sidewall of the building containing explosives to the eave line of any magazine, or building, or to a point 12 feet above thecenter of a railway or highway, will pass through such intervening natural or artificial barricade.

4 When two or more storage magazines are located on thesame property, each magazine must comply with the minimum distances specified from inhabited buildings, railways, and highways, and in addition, they should be separated fromeach other by not less than the distances shown for ‘‘Separation of Magazines,’’ except that the quantity of explosives contained in cap magazines shall govern in regard to the spacingof said cap magazines from magazines containing other explosives. If any two or more magazines are separated fromeach other by less than the specified ‘‘Separation of Magazines’’ distances, then such two or more magazines, as a group, must be considered as one magazine, and the total quantity of explosives stored in such group must be treated asif stored in a single magazine located on the site of any magazine of the group, and must comply with the minimum of distances specified from other magazines, inhabited buildings, railways, and highways.

5 This table applies only to the permanent storage of commercial explosives. It is not applicable to transportation of explosives, or any handling or temporary storage necessary orincident thereto. It is not intended to apply to bombs, projectiles, or other heavily encased explosives.

(vii) Except as provided in subdivision (viii) of this subparagraph, class IImagazines shall be located in conformity with Table H–21, but may bepermitted in warehouses and in wholesale and retail establishments when located on a floor which has an entrance at outside grade level and the magazine is located not more than 10 feet fromsuch an entrance. Two class II magazines may be located in the same building when one is used only for blasting caps in quantities not in excess of 5,000caps and a distance of 10 feet is maintained between magazines.

(viii) When used for temporary storage at a site for blasting operations, class II magazines shall be located away from other magazines. A distance of at least one hundred and fifty (150) feet shall be maintained between class II magazines and the work in progress when the quantity of explosives kept therein is in excess of 25 pounds, and atleast 50 feet when the quantity of explosives is 25 pounds, or less.

(ix) This paragraph (c) does not apply
to:

( a ) Stocks of small arms ammunition, propellant-actuated power cartridges, small arms ammunition primers in quantities of less than 750,000, or of smokeless propellants in quantities less than 750 pounds;

( b ) Explosive-actuated power devices when in quantities less than 50 pounds net weight of explosives;

( c ) Fuse lighters and fuse igniters; ( d ) Safety fuses other than cordeau
detonant fuses.

(2) Construction of magazines—general. (i) Magazines shall be constructed in conformity with the provisions of this paragraph.

(ii) Magazines for the storage of explosives, other than black powder, Class B and Class C explosives shall be bullet resistant, weather resistant, fire resistant, and ventilated sufficiently toprotect the explosive in the specific locality. Magazines used only for storage of black powder, Class B and Class C explosives shall be weather resistant, fire-resistant, and have ventilation. Magazines for storage of blasting and electric blasting caps shall be weatherresistant, fire-resistant, and ventilated.

(iii) Property upon which Class I magazines are located and property where Class II magazines are located outside of buildings shall be posted with signs reading ‘‘Explosives—Keep
Off.’’

(iv) Magazines requiring heat shall be heated by either hot-water radiant heating with the magazine building; or air directed into the magazine building over either hot water or low pressure steam (15 p.s.i.g.) coils located outside the magazine building.

(v) The magazine heating systems shall meet the following requirements:

( a ) The radiant heating coils within the building shall be installed in such amanner that the explosives or explosives containers cannot contact the


### 292 29 CFR Ch. XVII (7–1–15 Edition) § 1910.109

coils and air is free to circulate between the coils and the explosives or explosives containers.

( b ) The heating ducts shall be installed in such a manner that the hotair discharge from the duct is not directed against the explosives or explosives containers.

( c ) The heating device used in connection with a magazine shall have controls which prevent the ambient building temperature from exceeding 130 ° F.

( d ) The electric fan or pump used in the heating system for a magazine shall be mounted outside and separate from the wall of the magazine and shall be grounded.

( e ) The electric fan motor and the controls for electrical heating devices used in heating water or steam shall have overloads and disconnects, which comply with subpart S of this part. All electrical switch gear shall be located a minimum distance of 25 feet from the magazine.

(f

) The heating source for water orsteam shall be separated from the magazine by a distance of not less than 25 feet when electrical and 50 feet whenfuel fired. The area between the heating unit and the magazine shall be cleared of all combustible materials.

( g ) The storage of explosives and explosives containers in the magazine shall allow uniform air circulation so product temperature uniformity can be maintained.

(vi) When lights are necessary insidethe magazine, electric safety flashlight, or electric safety lanterns shall be used.

(3) Construction of Class I magazines.(i) Class I magazines shall be of masonry construction or of wood or of metal construction, or a combination of these types. Thickness of masonry units shall not be less than 8 inches.Hollow masonry units used in construction required to be bullet resistant shall have all hollow spaces filled with weak cement or well-tamped sand. Wood constructed walls, required to be bullet resistant, shall have at least a 6-inch space between interior and exterior sheathing and the space betweensheathing shall be filled with welltamped sand. Metal wall construction, when required to be bullet resistant, shall be lined with brick at least 4 inches in thickness or shall have at least a 6-inch sandfill between interior and exterior walls.

(ii) Floors and roofs of masonry magazines may be of wood construction. Wood floors shall be tongue and grooved lumber having a nominal thickness of 1 inch.

(iii) Roofs required to be bullet resistant shall be protected by a sand tray located at the line of eaves and covering the entire area except that necessary for ventilation. Sand in the sand tray shall be maintained at a depth of not less than 4 inches.

(iv) All wood at the exterior of magazines, including eaves, shall be protected by being covered with black or galvanized steel or aluminum metal of thickness of not less than No. 26 gage. All nails exposed to the interior of magazines shall be well countersunk.

(v) Foundations for magazines shallbe of substantial construction and arranged to provide good cross ventilation.

(vi) Magazines shall be ventilated sufficiently to prevent dampness andheating of stored explosives. Ventilating openings shall be screened to prevent the entrance of sparks.

(vii) Openings to magazines shall be restricted to that necessary for theplacement and removal of stocks of explosives. Doors for openings in magazines for Class A explosives shall be bullet resistant. Doors for magazines not required to be bullet resistant shall be designed to prevent unauthorized entrance to the magazine.

(viii) [Reserved](ix) Provisions shall be made to prevent the piling of stocks of explosivesdirectly against masonry walls, bricklined or sand-filled metal walls and single-thickness metal walls; such protection, however, shall not interfere with proper ventilation at the interior of side and end walls.

(4) Construction of Class II magazines. (i) Class II magazines shall be of woodor metal construction, or a combination thereof.

(ii) Wood magazines of this class shall have sides, bottom, and cover constructed of 2-inch hardwood boards well braced at corners and protected by being entirely covered with sheet


### 293 Occupational Safety and Health Admin., Labor § 1910.109

metal of not less than No. 20 gage. All nails exposed to the interior of the magazine shall be well countersunk. All metal magazines of this class shallhave sides, bottom, and cover constructed of sheet metal, and shall be lined with three-eighths-inch plywood or equivalent. Edges of metal covers shall overlap sides at least 1 inch.

(iii) Covers for both wood- and metalconstructed magazines of this class shall be provided with substantial strap hinges and shall be provided with substantial means for locking.

(iv) Magazines of this class shall be painted red and shall bear lettering in white, on all sides and top, at least 3 inches high, ‘‘Explosives—Keep FireAway.’’ Class II magazines when located in warehouses, and in wholesaleand retail establishments shall be provided with substantial wheels or casters to facilitate easy removal in thecase of fire. Where necessary due to climatic conditions, Class II magazines shall be ventilated.

(5) Storage within magazines. (i) Packages of explosives shall be laid flat with top side up. Black powder whenstored in magazines with other explosives shall be stored separately. Black powder stored in kegs shall be stored on ends, bungs down, or on side, seams down. Corresponding grades and brandsshall be stored together in such a manner that brands and grade marks show. All stocks shall be stored so as to be easily counted and checked. Packages of explosives shall be piled in a stable manner. When any kind of explosive is removed from a magazine for use, the oldest explosive of that particular kind shall always be taken first.

(ii) Packages of explosives shall not be unpacked or repacked in a magazine nor within 50 feet of a magazine or in close proximity to other explosives.Tools used for opening packages of explosives shall be constructed of nonsparking materials, except that metalslitters may be used for opening fiberboard boxes. A wood wedge and a fiber, rubber, or wood mallet shall be used for opening or closing wood packages ofexplosives. Opened packages of explosives shall be securely closed before being returned to a magazine.

(iii) Magazines shall not be used for the storage of any metal tools nor any commodity except explosives, but thisrestriction shall not apply to the storage of blasting agents and blasting supplies.

(iv) Magazine floors shall be regularly swept, kept clean, dry, free of grit, paper, empty used packages, and rubbish. Brooms and other cleaningutensils shall not have any spark-producing metal parts. Sweepings from floors of magazines shall be properly disposed of. Magazine floors stainedwith nitroglycerin shall be cleaned according to instructions by the manufacturer.

(v) When any explosive has deteriorated to an extent that it is in an unstable or dangerous condition, or if nitroglycerin leaks from any explosives, then the person in possession of such explosive shall immediately proceed to destroy such explosive in accordance
with the instructions of the manufacturer. Only experienced persons shall be allowed to do the work of destroying explosives.

(vi) When magazines need inside repairs, all explosives shall be removed
therefrom and the floors cleaned. In making outside repairs, if there is a possibility of causing sparks or fire the explosives shall be removed from the magazine. Explosives removed from a magazine under repair shall either be placed in another magazine or placed a safe distance from the magazine wherethey shall be properly guarded and protected until repairs have been completed, when they shall be returned to the magazine.

(vii) Smoking, matches, open flames, spark-producing devices, and firearms (except firearms carried by guards) shall not be permitted inside of or within 50 feet of magazines. The land surrounding a magazine shall be kept
clear of all combustible materials for a
distance of at least 25 feet. Combustible materials shall not be stored within 50 feet of magazines.

(viii) Magazines shall be in the charge of a competent person at all times and who shall be held responsiblefor the enforcement of all safety precautions.


### 294 29 CFR Ch. XVII (7–1–15 Edition) § 1910.109

(ix) Explosives recovered from blasting misfires shall be placed in a separate magazine until competent personnel has determined from the manufacturer the method of disposal. Caps recovered from blasting misfires shall not be reused. Such explosives and caps shall then be disposed of in the manner recommended by the manufacturer.

(d) Transportation of explosives—(1) General provisions. (i) No employee shall be allowed to smoke, carry matches or any other flame-producing device, or carry any firearms or loadedcartridges while in or near a motor vehicle transporting explosives; or drive,load, or unload such vehicle in a careless or reckless manner.

(ii) [Reserved](iii) Explosives shall not be transferred from one vehicle to another within the confines of any jurisdiction (city, county, State, or other area) without informing the fire and police departments thereof. In the event of
breakdown or collision the local fire and police departments shall be promptly notified to help safeguard such emergencies. Explosives shall be
transferred from the disabled vehicle to another only, when proper and qualified supervision is provided.

(iv) Blasting caps or electric blasting caps shall not be transported over the highways on the same vehicles withother explosives, unless packaged, segregated, and transported in accordancewith the Department of Transportation’s Hazardous Materials Regulations (49 CFR parts 177–180).

(2) Transportation vehicles. (i) Vehicles used for transporting explosives shall be strong enough to carry the loadwithout difficulty and be in good mechanical condition. If vehicles do not have a closed body, the body shall becovered with a flameproof and moistureproof tarpaulin or other effective protection against moisture andsparks. All vehicles used for the transportation of explosives shall have tight floors and any exposed spark-producing metal on the inside of the body shall be
covered with wood or other nonsparking materials to prevent contact with packages of explosives. Packages of explosives shall not be loaded above the sides of an open-body vehicle. (ii) Every vehicle used for transporting explosives and oxidizing materials listed in paragraph (d)(2)(ii)( a ) of
this section shall be marked as follows:

( a ) Exterior markings or placards required on applicable vehicles shall be
as follows for the various classes of
commodities:

Commodity Type of marking or placard

Explosives, Class A, any quantity

or a combination of Class A and Class B explosives. Explosives A (Red letters on white background).

Explosives, Class B, and quantity Explosives B (Red letters on white background). Oxidizing material (blasting

agents, ammonium nitrate, etc.), 1,000 pounds or more gross weight. Oxidizers (Yellow letters on black background).

( b ) [Reserved] ( c ) Such markings or placards shall be displayed at the front, rear, and on
each side of the motor vehicle or trailer, or other cargo carrying body whileit contains explosives or other dangerous articles of such type and in such quantity as specified in paragraph (d)(1)(ii)( a ) of this subdivision. Thefront marking or placard may be displayed on the front of either the truck,truck body, truck tractor or the trailer.

( d ) Any motor vehicle, trailer, or other cargo-carrying body containing more than one kind of explosive as well as an oxidizing material requiring aplacard under the provisions of paragraph (d)(2)(ii)( a ), the aggregate gross weight of which totals 1,000 pounds or more, shall be marked or placarded ‘‘Dangerous’’ as well as ‘‘Explosive A’’or ‘‘Explosive B’’ as appropriate. If explosives Class A and explosives Class B are loaded on the same vehicle, the ‘‘Explosives B’’ marking need not be displayed.

( e ) In any combination of two or more vehicles containing explosives or other dangerous articles each vehicle shall be marked or placarded as to itscontents and in accordance with paragraphs (d)(2)(ii) ( a ) and ( c ) of this subdivision.

(iii) Each motor vehicle used for transporting explosives shall beequipped with a minimum of two extinguishers, each having a rating of at least 10–BC.


### 295 Occupational Safety and Health Admin., Labor § 1910.109

( a ) Only extinguishers listed or approved by a nationally recognized testing laboratory shall be deemed suitable for use on explosives-carrying vehicles.Refer to §1910.155(c)(3)(iv)(A) for definition of listed, and §1910.7 for nationally recognized testing laboratory.

( b ) Extinguishers shall be filled and ready for immediate use and located near the driver’s seat. Extinguishers shall be examined periodically by a competent person.

(iv) A motor vehicle used for transporting explosives shall be given the following inspection to determine thatit is in proper condition for safe transportation of explosives:

( a ) Fire extinguishers shall be filled and in working order.

( b ) All electrical wiring shall be completely protected and securely fastened to prevent short-circuiting.

( c ) Chassis, motor, pan, and underside of body shall be reasonably clean and free of excess oil and grease.

( d ) Fuel tank and feedline shall be secure and have no leaks.

( e ) Brakes, lights, horn, windshield wipers, and steering apparatus shall function properly.

(f

) Tires shall be checked for proper inflation and defects.

( g ) The vehicle shall be in proper condition in every other respect and acceptable for handling explosives.

(3) Operation of transportation vehicles. (i) Vehicles transporting explosives shall only be driven by and be in the charge of a driver who is familiar with the traffic regulations, State laws, and the provisions of this section.

(ii) Except under emergency conditions, no vehicle transporting explosives shall be parked before reaching its destination, even though attended, on any public street adjacent to or in proximity to any place where people work.

(iii) Every motor vehicle transporting any quantity of Class A or Class B explosives shall, at all times,be attended by a driver or other attendant of the motor carrier. This attendant shall have been made aware of the class of the explosive material in the vehicle and of its inherent dangers, and shall have been instructed in the measures and procedures to be followed in order to protect the public from those dangers. He shall have been made
familiar with the vehicle he is assigned, and shall be trained, suppliedwith the necessary means, and authorized to move the vehicle when required.

( a ) For the purpose of this subdivision, a motor vehicle shall be deemed ‘‘attended’’ only when the driver or other attendant is physically on or in the vehicle, or has the vehicle within
his field of vision and can reach itquickly and without any kind of interference ‘‘attended’’ also means that the driver or attendant is awake, alert, andnot engaged in other duties or activities which may divert his attention from the vehicle, except for necessary communication with public officers, or representatives of the carrier shipper, or consignee, or except for necessary
absence from the vehicle to obtain food or to provide for his physical comfort.

( b ) However, an explosive-laden vehicle may be left unattended if parked within a securely fenced or walled area with all gates or entrances lockedwhere parking of such vehicle is otherwise permissible, or at a magazine site established solely for the purpose of storing explosives.

(iv) No spark-producing metal, sparkproducing metal tools, oils, matches, firearms, electric storage batteries, flammable substances, acids, oxidizing materials, or corrosive compounds shall be carried in the body of any
motor truck and/or vehicle transporting explosives, unless the loadingof such dangerous articles and the explosives comply with U.S. Department of Transportation regulations.

(v) Vehicles transporting explosives shall avoid congested areas and heavytraffic. Where routes through congested areas have been designated by
local authorities such routes shall be
followed.

(vi) Delivery shall only be made to authorized persons and into authorized magazines or authorized temporary storage or handling areas.

(e) Use of explosives and blasting agents—(1) General provisions. (i) While explosives are being handled or used, smoking shall not be permitted and no one near the explosives shall possess matches, open light or other fire or flame. No person shall be allowed to


### 296 29 CFR Ch. XVII (7–1–15 Edition) § 1910.109

handle explosives while under the influence of intoxicating liquors, narcotics, or other dangerous drugs.

(ii) Original containers or Class IImagazines shall be used for taking detonators and other explosives from storage magazines to the blasting area.

(iii) When blasting is done in congested areas or in close proximity to a structure, or any other installation that may be damaged, the blast shall be covered before firing with a matconstructed so that it is capable of preventing fragments from being thrown.

(iv) Persons authorized to prepare explosive charges or conduct blasting operations shall use every reasonable precaution, including but not limited to warning signals, flags, barricades, or woven wire mats to insure the safety of the general public and workmen.

(v) Blasting operations shall be conducted during daylight hours.

(vi) Whenever blasting is being conducted in the vicinity of gas, electric, water, fire alarm, telephone, telegraph, and steam utilities, the blaster shall notify the appropriate representativesof such utilities at least 24 hours in advance of blasting, specifying the location and intended time of such blasting. Verbal notice shall be confirmed with written notice.

(vii) Due precautions shall be takento prevent accidental discharge of electric blasting caps from current induced by radar, radio transmitters, lightning, adjacent powerlines, dust storms, or other sources of extraneous electricity. These precautions shall include:

( a ) The suspension of all blasting operations and removal of persons from the blasting area during the approach and progress of an electric storm.

( b ) The posting of signs warningagainst the use of mobile radio transmitters on all roads within 350 feet of the blasting operations.

(2) Storage at use sites. (i) Empty containers and paper and fiber packingmaterials which have previously contained explosive materials shall be disposed of in a safe manner, or reused in accordance with the Department of Transportation’s Hazardous Materials Regulations (49 CFR parts 177–180).

(ii) Containers of explosives shall not be opened in any magazine or within 50 feet of any magazine. In opening kegs or wooden cases, no sparking metal tools shall be used; wooden wedges and either wood, fiber or rubber mallets shall be used. Nonsparking metallicslitters may be used for opening fiberboard cases.

(iii) Explosives or blasting equipmentthat are obviously deteriorated or damaged shall not be used.

(iv) No explosives shall be abandoned. (3) Loading of explosives in blast holes. (i) All drill holes shall be sufficiently large to admit freely the insertion of the cartridges of explosives.

(ii) Tamping shall be done only with wood rods without exposed metal parts, but nonsparking metal connectors maybe used for jointed poles. Violent tamping shall be avoided. Primed cartridges shall not be tamped.

(iii) When loading blasting agents pneumatically over electric blasting caps, semiconductive delivery hose shall be used and the equipment shall be bonded and grounded.

(iv) No holes shall be loaded except those to be fired in the next round of blasting. After loading, all remainingexplosives shall be immediately returned to an authorized magazine.

(v) Drilling shall not be started untilall remaining butts of old holes are examined with a wooden stick for unexploded charges, and if any are found, they shall be refired before work proceeds.

(vi) No person shall be allowed todeepen drill holes which have contained explosives.

(vii) After loading for a blast is completed, all excess blasting caps or electric blasting caps and other explosives shall immediately be returned to their separate storage magazines.

(4) Initiation of explosive charges. (i) [Reserved] (ii) When fuse is used, the blasting cap shall be securely attached to the safety fuse with a standard-ring typecap crimper. All primers shall be assembled at least 50 feet from any magazine.

(iii) Primers shall be made up only as required for each round of blasting.

(iv) No blasting cap shall be inserted in the explosives without first making a hole in the cartridge for the cap witha wooden punch of proper size or standard cap crimper.


### 297 Occupational Safety and Health Admin., Labor § 1910.109

(v) Explosives shall not be extracted from a hole that has once been charged or has misfired unless it is impossible to detonate the unexploded charge by insertion of a fresh additional primer.

(vi) If there are any misfires while using cap and fuse, all persons shall be required to remain away from the charge for at least 1 hour. If electricblasting caps are used and a misfire occurs, this waiting period may be reduced to 30 minutes. Misfires shall behandled under the direction of the person in charge of the blasting and all wires shall be carefully traced and search made for unexploded charges.

(vii) Blasters, when testing circuitsto charged holes, shall use only blasting galvanometers designed for this

purpose.

(viii) Only the employee making leading wire connections in electrical firing shall be allowed to fire the shot. Leading wires shall remain shorted andnot be connected to the blasting machine or other source of current until the charge is to be fired.

(5) Warning required. Before a blast is fired, the employer shall require that a loud warning signal be given by the person in charge, who has made certain that all surplus explosives are in a safe place, all persons and vehicles are at a safe distance or under sufficient cover, and that an adequate warning has been given.

(f) Explosives at piers, railway stations, and cars or vessels not otherwise specified in this standard—(1) Railway cars. Except in an emergency and with permission of the local authority, no personshall have or keep explosives in a railway car unless said car and contentsand methods of loading are in accordance with the U.S. Department of Transportation Regulations for the Transportation of Explosives, 49 CFR chapter I.

(2) Packing and marking. No personshall deliver any explosive to any carrier unless such explosive conforms in all respects, including marking and packing, to the U.S. Department of Transportation Regulations for the Transportation of Explosives.

(3) Marking cars. Every railway car containing explosives which has reached its designation, or is stoppedin transit so as no longer to be in interstate commerce, shall have attached to both sides and ends of the car, cards with the words ‘‘Explosives—HandleCarefully—Keep Fire Away’’ in red letters at least 1 1 ⁄ 2 inches high on a white background.

(4) Storage. Any explosives at a railway facility, truck terminal, pier,wharf harbor facility, or airport terminal whether for delivery to a consignee, or forwarded to some other destination shall be kept in a safe place, isolated as far as practicable and in such manner that they can be easily and quickly removed.

(5) Hours of transfer. Explosives shall not be delivered to or received from any railway station, truck terminal, pier, wharf, harbor facility, or airport terminal between the hours of sunset and sunrise.

(g) Blasting agents—(1) General. Unless otherwise set forth in this paragraph, blasting agents, excluding water gels, shall be transported, stored, and used in the same manner as explosives. Water gels are covered in paragraph (h) of this section.

(2) Fixed location mixing. (i) [Reserved]

(ii) Buildings used for the mixing ofblasting agents shall conform to the requirements of this section.

( a ) Buildings shall be of noncombustible construction or sheet metal on wood studs.

( b ) Floors in a mixing plant shall be of concrete or of other nonabsorbent materials.

( c ) All fuel oil storage facilities shall be separated from the mixing plant and located in such a manner that in case of tank rupture, the oil will drain away from the mixing plant building.

( d ) The building shall be well ventilated.

( e ) Heating units which do not dependon combustion processes, when properly designed and located, may be used in the building. All direct sources of heat shall be provided exclusively fromunits located outside the mixing building.

(f

) All internal-combustion engines used for electric power generation shall be located outside the mixing plantbuilding, or shall be properly ventilated and isolated by a firewall. The exhaust systems on all such engines shall


### 298 29 CFR Ch. XVII (7–1–15 Edition) § 1910.109

be located so any spark emission cannot be a hazard to any materials in or adjacent to the plant.

(iii) Equipment used for mixingblasting agents shall conform to the requirements of this subdivision.

( a ) The design of the mixer shall minimize the possibility of frictional heating, compaction, and especially confinement. All bearings and drive assemblies shall be mounted outside themixer and protected against the accumulation of dust. All surfaces shall be accessible for cleaning.

( b ) Mixing and packaging equipmentshall be constructed of materials compatible with the fuel-ammonium nitrate composition.

( c ) Suitable means shall be provided to prevent the flow of fuel oil to the mixer in case of fire. In gravity flow systems an automatic spring-loaded shutoff valve with fusible link shall be installed.

(iv) The provisions of this subdivision shall be considered when determining blasting agent compositions.

( a ) The sensitivity of the blasting agent shall be determined by means ofa No. 8 test blasting cap at regular intervals and after every change in formulation.

( b ) Oxidizers of small particle size, such as crushed ammonium nitrate prills or fines, may be more sensitivethan coarser products and shall, therefore, be handled with greater care.

( c ) No hydrocarbon liquid fuel withflashpoint lower than that of No. 2 diesel fuel oil 125 ° F. minimum shall be used.

( d ) Crude oil and crankcase oil shall not be used.

( e ) Metal powders such as aluminum shall be kept dry and shall be stored incontainers or bins which are moistureresistant or weathertight. Solid fuelsshall be used in such manner as to minimize dust explosion hazards.

(f

) Peroxides and chlorates shall not be used.

(v) All electrical switches, controls,motors, and lights located in the mixing room shall conform to the requirements in subpart S of this part for Class II, Division 2 locations; otherwisethey shall be located outside the mixing room. The frame of the mixer and all other equipment that may be used shall be electrically bonded and be provided with a continuous path to the ground.

(vi) Safety precautions at mixing plants shall include the requirements of this subdivision.

( a ) Floors shall be constructed so as to eliminate floor drains and piping into which molten materials could flow and be confined in case of fire.

( b ) The floors and equipment of the mixing and packaging room shall be cleaned regularly and thoroughly to prevent accumulation of oxidizers or fuels and other sensitizers.

( c ) The entire mixing and packaging plant shall be cleaned regularly andthoroughly to prevent excessive accumulation of dust.

( d ) Smoking, matches, open flames, spark-producing devices, and firearms (except firearms carried by guards) shall not be permitted inside of orwithin 50 feet of any building or facility used for the mixing of blasting agents.

( e ) The land surrounding the mixing plant shall be kept clear of brush, dried grass, leaves, and other materials for a distance of at least 25 feet.

(f

) Empty ammonium nitrate bagsshall be disposed of daily in a safe manner.

( g ) No welding shall be permitted oropen flames used in or around the mixing or storage area of the plant unlessthe equipment or area has been completely washed down and all oxidizer material removed.

( h ) Before welding or repairs to hollow shafts, all oxidizer material shall be removed from the outside and inside of the shaft and the shaft vented with a minimum one-half inch diameter opening.

( i ) Explosives shall not be permittedinside of or within 50 feet of any building or facility used for the mixing of blasting agents.

(3) Bulk delivery and mixing vehicles. (i) The provisions of this paragraphshall apply to off-highway private operations as well as to all public highway
movements.

(ii) A bulk vehicle body for deliveringand mixing blasting agents shall conform with the requirements of this paragraph (ii).


### 299 Occupational Safety and Health Admin., Labor § 1910.109

( a ) The body shall be constructed of
noncombustible materials.

( b ) Vehicles used to transport bulk premixed blasting agents on public highways shall have closed bodies.

( c ) All moving parts of the mixing system shall be designed as to prevent a heat buildup. Shafts or axles whichcontact the product shall have outboard bearings with 1-inch minimum clearance between the bearings and theoutside of the product container. Particular attention shall be given to the clearances on all moving parts.

( d ) A bulk delivery vehicle shall bestrong enough to carry the load without difficulty and be in good mechanical condition.

(iii) Operation of bulk delivery vehicles shall conform to the requirements
of this subdivision. These include the placarding requirements as specified by Department of Transportation.

( a ) The operator shall be trained inthe safe operation of the vehicle together with its mixing, conveying, and related equipment. The employer shall assure that the operator is familiar with the commodities being delivered and the general procedure for handling emergency situations.

( b ) The hauling of either blasting caps or other explosives but not both,shall be permitted on bulk trucks provided that a special wood or nonferrous-lined container is installed for the explosives. Such blasting caps orother explosives shall be in DOT-specified shipping containers: see 49 CFR chapter I.

( c ) No person shall smoke, carrymatches or any flame-producing device, or carry any firearms while in orabout bulk vehicles effecting the mixing transfer or down-the-hole loadingof blasting agents at or near the blasting site.

( d ) Caution shall be exercised in themovement of the vehicle in the blasting area to avoid driving the vehicle over or dragging hoses over firing lines, cap wires, or explosive materials. The employer shall assure that the driver, in moving the vehicle, has assistance ofa second person to guide his movements.

( e ) No intransit mixing of materials shall be performed. (iv) Pneumatic loading from bulk delivery vehicles into blastholes primed with electric blasting caps or other static-sensitive systems shall conform to the requirements of this subdivision.

( a ) A positive grounding device shall be used to prevent the accumulation of static electricity.

( b ) A discharge hose shall be used that has a resistance range that will prevent conducting stray currents, but that is conductive enough to bleed off static buildup.

( c ) A qualified person shall evaluate all systems to determine if they willadequately dissipate static under potential field conditions.

(v) Repairs to bulk delivery vehicles shall conform to the requirements of this section.

( a ) No welding or open flames shall be used on or around any part of the delivery equipment unless it has beencompletely washed down and all oxidizer material removed.

( b ) Before welding or making repairs to hollow shafts, the shaft shall be thoroughly cleaned inside and out and vented with a minimum one-half-inch diameter opening.

(4) Bulk storage bins. (i) The bin, including supports, shall be constructed of compatible materials, waterproof, and adequately supported and braced to withstand the combination of all loads including impact forces arising from product movement within the bin and accidental vehicle contact with the support legs.

(ii) The bin discharge gate shall be designed to provide a closure tight enough to prevent leakage of the stored product. Provision shall also be made so that the gate can be locked.

(iii) Bin loading manways or access hatches shall be hinged or otherwise attached to the bin and be designed to permit locking.

(iv) Any electrically driven conveyors for loading or unloading bins shall conform to the requirements of subpart S of this part. They shall bedesigned to minimize damage from corrosion.

(v) Bins containing blasting agentshall be located, with respect to inhabited buildings, passenger railroads, and public highways, in accordance with Table-21 and separation from other


### 300 29 CFR Ch. XVII (7–1–15 Edition) § 1910.109

blasting agent storage and explosives storage shall be in conformity with
Table H–22.

(vi) Bins containing ammonium nitrate shall be separated from blasting agent storage and explosives storage in conformity with Table H–22.

TABLE H–22—TABLE OF R ECOMMENDED S EPA

RATION D ISTANCES OF A MMONIUM N ITRATE

AND B LASTING A GENTS F ROM E XPLOSIVES OR B LASTING A GENTS 1 6

Donor weight Minimum separation distance of receptor when barricaded 2 (ft.) Minimum thickness of artificial

barricades 5

(in.) Pounds

over Pounds not over Ammonium nitrate 3 Blasting agent 4

100 3 11 12

100 300 4 14 12

300 600 5 18 12 600 1,000 6 22 12 1,000 1,600 7 25 12 1,600 2,000 8 29 12 2,000 3,000 9 32 15 3,000 4,000 10 36 15 4,000 6,000 11 40 15 6,000 8,000 12 43 20 8,000 10,000 13 47 20 10,000 12,000 14 50 20 12,000 16,000 15 54 25 16,000 20,000 16 58 25 20,000 25,000 18 65 25 25,000 30,000 19 68 30 30,000 35,000 20 72 30 35,000 40,000 21 76 30 40,000 45,000 22 79 35 45,000 50,000 23 83 35 50,000 55,000 24 86 35 55,000 60,000 25 90 35 60,000 70,000 26 94 40 70,000 80,000 28 101 40 80,000 90,000 30 108 40 90,000 100,000 32 115 40 100,000 120,000 34 122 50 120,000 140,000 37 133 50 140,000 160,000 40 144 50 160,000 180,000 44 158 50 180,000 200,000 48 173 50 200,000 220,000 52 187 60 220,000 250,000 56 202 60 250,000 275,000 60 216 60 275,000 300,000 64 230 60

1 These distances apply to the separation of stores only. Table H–21 shall be used in determining separation distancesfrom inhabited buildings, passenger railways, and public highways.

2 When the ammonium nitrate and/or blasting agent is notbarricaded, the distances shown in the table shall be multiplied by six. These distances allow for the possibility of high velocity metal fragments from mixers, hoppers, truck bodies, sheet metal structures, metal container, and the like which may enclose the ‘‘donor’’. Where storage is in bullet-resistant magazines recommended for explosives or where the storage is protected by a bullet-resistant wall, distances, and barricade thicknesses in excess of those prescribed in Table H–21 are not required. 3 The distances in the table apply to ammonium nitrate thatpasses the insensitivity test prescribed in the definition of ammonium nitrate fertilizer promulgated by the National Plant Food Institute*; and ammonium nitrate failing to pass said testshall be stored at separation distances determined by competent persons. (*Definition and Test Procedures for Ammonium Nitrate Fertilizer, National Plant Food Institute, November 1964.)

4 These distances apply to nitro-carbo-nitrates and blasting agents which pass the insensitivity test prescribed in the U.S. Department of Transportation (DOT) regulations.

5 Earth, or sand dikes, or enclosures filled with the prescribed minimum thickness of earth or sand are acceptable artificial barricades. Natural barricades, such as hills or timberof sufficient density that the surrounding exposures which require protection cannot be seen from the ‘‘donor’’ when the trees are bare of leaves, are also acceptable.

6 When the ammonium nitrate must be counted in determining the distances to be maintained from inhabited buildings, passenger railways and public highways, it may be counted at one-half its actual weight because its blast effect is lower.

N OTE 7: Guide to use of table of recommended separationdistances of ammonium nitrate and blasting agents from explosives or blasting agents.

(a) Sketch location of all potential donor and acceptor materials together with the maximum mass of material to be allowed in that vicinity. (Potential donors are high explosives,blasting agents, and combination of masses of detonating materials. Potential acceptors are high explosives, blasting agents, and ammonium nitrate.)

(b) Consider separately each donor mass in combination with each acceptor mass. If the masses are closer than table allowance (distances measured between nearest edges), the combination of masses becomes a new potential donor of weight equal to the total mass. When individual masses are considered as donors, distances to potential acceptors shall be measured between edges. When combined masses within propagating distance of each other are considered as adonor, the appropriate distance to the edge of potential acceptors shall be computed as a weighted distance from the combined masses.

Calculation of weighted distance from combined masses: Let M 2 , M 3

. . . M

n be donor masses to be combined. M1 is a potential acceptor mass. D12 is distance from M 1 to M 2 (edge to edge).
D13 is distance from M 1 to M 3 (edge to edge), etc. To find weighted distance [ D1 ( 2 , 3

. . . n )] from combined masses to M1 , add the products of the individual masses and distances and divide the total by the sum of the masses thus:

D1 ( 2 , 3

. . . n )= M 2× D12 + M 3 × D12 . . . + M

n × D12 M 2 + M 3

. . . + M

n Propagation is possible if either an individual donor mass isless than the tabulated distance from an acceptor or a combined mass is less than the weighted distance from an acceptor.

(c) In determining the distances separating highways, railroads, and inhabited buildings from potential explosions (as prescribed in Table H–21), the sum of all masses which may propagate (i.e., lie at distances less than prescribed in the Table) from either individual or combined donor masses areincluded. However, when the ammonium nitrate must be included, only 50 percent of its weight shall be used because of its reduced blast effects. In applying Table H–21 to distances from highways, railroads, and inhabited buildings, distances are measured from the nearest edge of potentially explodable material as prescribed in Table H–21, Note 5.

(d) When all or part of a potential acceptor comprises Explosives Class A as defined in DOT regulations, storage in bullet-resistant magazines is required. Safe distances to stores in bullet-resistant magazines may be obtained from the intermagazine distances prescribed in Table H–21.

(e) Barricades must not have line-of-sight openings between potential donors and acceptors which permit blast or missiles to move directly between masses.

(f) Good housekeeping practices shall be maintained around any bin containing ammonium nitrate or blasting agent. This includes keeping weeds and other combustible materials cleared within 25 feet of such bin. Accumulation of spilled product on the ground shall be prevented.

(5) Storage of blasting agents and supplies. (i) Blasting agents and oxidizers used for mixing of blasting agents shall


### 301 Occupational Safety and Health Admin., Labor § 1910.109

be stored in the manner set forth in this subdivision.

( a ) Blasting agents or ammonium nitrate, when stored in conjunction withexplosives, shall be stored in the manner set forth in paragraph (c) of this section for explosives. The mass of blasting agents and one-half the mass of ammonium nitrate shall be included when computing the total quantity ofexplosives for determining distance requirements.

( b ) Blasting agents, when stored entirely separate from explosives, may bestored in the manner set forth in paragraph (c) of this section or in one-story warehouses (without basements) which shall be:

( 1 ) Noncombustible or fire resistive; ( 2 ) Constructed so as to eliminate open floor drains and piping into which molten materials could flow and be confined in case of fire;

( 3 ) Weather resistant; ( 4 ) Well ventilated; and ( 5 ) Equipped with a strong door kept securely locked except when open for business.

( c ) Semitrailer or full-trailer vansused for highway or onsite transportation of the blasting agents are satisfactory for temporarily storing these materials, provided they are located inaccordance with Table H–22 with respect to one another. Trailers shall be provided with substantial means for locking, and the trailer doors shall be kept locked, except during the time of placement and removal of stocks of blasting agents.

(ii) Warehouses used for the storageof blasting agents separate from explosives shall be located as set forth in this subdivision.

( a ) Warehouses used for the storage of blasting agents shall be located in Table H–22 with respect to one another.

( b ) If both blasting agents and ammonium nitrate are handled or storedwithin the distance limitations prescribed through paragraph (g)(2) of thissection, one-half the mass of the ammonium nitrate shall be added to themass of the blasting agent when computing the total quantity of explosives for determining the proper distance for compliance with Table H–21.

(iii) Smoking, matches, open flames, spark producing devices, and firearms are prohibited inside of or within 50feet of any warehouse used for the storage of blasting agents. Combustible materials shall not be stored within 50 feet of warehouses used for the storage of blasting agents.

(iv) The interior of warehouses used for the storage of blasting agents shall be kept clean and free from debris and empty containers. Spilled materials shall be cleaned up promptly and safelyremoved. Combustible materials, flammable liquids, corrosive acids, chlorates, or nitrates shall not be stored in any warehouse used for blasting agentsunless separated therefrom by a fire resistive separation of not less than 1 hour resistance. The provisions of thissubdivision shall not prohibit the storage of blasting agents together with nonexplosive blasting supplies.

(v) Piles of ammonium nitrate andwarehouses containing ammonium nitrate shall be adequately separated from readily combustible fuels.

(vi) Caked oxidizers, either in bags orin bulk, shall not be loosened by blasting.

(vii) Every warehouse used for the storage of blasting agents shall be under the supervision of a competent

person.

(6) Transportation of packaged blasting agents. (i) When blasting agents are transported in the same vehicle with explosives, all of the requirements of paragraph (d) of this section shall be complied with.

(ii) Vehicles transporting blasting agents shall only be driven by and be in charge of a driver in possession of a valid motor vehicle operator’s license. Such a person shall also be familiar with the State’s vehicle and traffic
laws.

(iii) No matches, firearms, acids, or other corrosive liquids shall be carriedin the bed or body of any vehicle containing blasting agents.

(iv) No person shall be permitted toride upon, drive, load, or unload a vehicle containing blasting agents whilesmoking or under the influence of intoxicants, narcotics, or other dangerous drugs.

(v) [Reserved] (vi) Vehicles transporting blastingagents shall be in safe operating condition at all times.


### 302 29 CFR Ch. XVII (7–1–15 Edition) § 1910.109

(7) Use of blasting agents. Persons using blasting agents shall comply with all of the applicable provisions of paragraph (e) of this section.

(h) Water gel (Slurry) explosives and blasting agents—(1) General provisions.Unless otherwise set forth in this paragraph, water gels shall be transported, stored and used in the same manner asexplosives or blasting agents in accordance with the classification of the product.

(2) Types and classifications. (i) Water gels containing a substance in itselfclassified as an explosive shall be classified as an explosive and manufactured, transported, stored, and used asspecified for ‘‘explosives’’ in this section, except as noted in subdivision (iv) of this subparagraph.

(ii) Water gels containing no substance in itself classified as an explosive and which are cap-sensitive as defined in paragraph (a) of this section under Blasting Agent shall be classified as an explosive and manufactured,transported, stored and used as specified for ‘‘explosives’’ in this section.

(iii) Water gels containing no substance in itself classified as an explosive and which are not cap-sensitive as defined in paragraph (a) of this section under Blasting Agent shall be classified as blasting agents and manufactured,transported, stored, and used as specified for ‘‘blasting agents’’ in this section.

(iv) When tests on specific formulations of water gels result in Department of Transportation classification as a Class B explosive, bullet-resistantmagazines are not required, see paragraph (c)(2)(ii) of this section.

(3) Fixed location mixing. (i) [Reserved] (ii) Buildings used for the mixing ofwater gels shall conform to the requirements of this subdivision.

( a ) Buildings shall be of noncombustible construction or sheet metal on wood studs.

( b ) Floors in a mixing plant shall be of concrete or of other nonabsorbent materials.

( c ) Where fuel oil is used all fuel oil storage facilities shall be separated from the mixing plant and located insuch a manner that in case of tank rupture, the oil will drain away from the mixing plant building.

( d ) The building shall be well ventilated.

( e ) Heating units that do not dependon combustion processes, when properly designed and located, may be used in the building. All direct sources of heat shall be provided exclusively from units located outside of the mixing building.

(f

) All internal-combustion engines used for electric power generation shall be located outside the mixing plantbuilding, or shall be properly ventilated and isolated by a firewall. The exhaust systems on all such engines shallbe located so any spark emission cannot be a hazard to any materials in or adjacent to the plant.

(iii) Ingredients of water gels shall conform to the requirements of this subdivision.

( a ) Ingredients in themselves classified as Class A or Class B explosives shall be stored in conformity with paragraph (c) of this section.

( b ) Nitrate-water solutions may be stored in tank cars, tank trucks, orfixed tanks without quantity or distance limitations. Spills or leaks whichmay contaminate combustible materials shall be cleaned up immediately.

( c ) Metal powders such as aluminum shall be kept dry and shall be stored incontainers or bins which are moistureresistant or weathertight. Solid fuelsshall be used in such manner as to minimize dust explosion hazards.

( d ) Ingredients shall not be stored with incompatible materials.

( e ) Peroxides and chlorates shall not be used.

(iv) Mixing equipment shall complywith the requirements of this subdivision.

( a ) The design of the processingequipment, including mixing and conveying equipment, shall be compatiblewith the relative sensitivity of the materials being handled. Equipment shall be designed to minimize the possibilityof frictional heating, compaction, overloading, and confinement.

( b ) Both equipment and handling procedures shall be designed to prevent the introduction of foreign objects or materials.


### 303 Occupational Safety and Health Admin., Labor § 1910.109

( c ) Mixers, pumps, valves, and related equipment shall be designed to permit regular and periodic flushing, cleaning, dismantling, and inspection.

( d ) All electrical equipment including wiring, switches, controls, motors, andlights, shall conform to the requirements of subpart S of this part.

( e ) All electric motors and generatorsshall be provided with suitable overload protection devices. Electrical generators, motors, proportioning devices, and all other electrical enclosures shall be electrically bonded. The groundingconductor to all such electrical equipment shall be effectively bonded to the service-entrance ground connectionand to all equipment ground connections in a manner so as to provide a continuous path to ground.

(v) Mixing facilities shall comply with the fire prevention requirements of this subdivision.

( a ) The mixing, loading, and ingredient transfer areas where residues or spilled materials may accumulate shall be cleaned periodically. A cleaning andcollection system for dangerous residues shall be provided. ,

( b ) A daily visual inspection shall bemade of mixing, conveying, and electrical equipment to establish that suchequipment is in good operating condition. A program of systematic maintenance shall be conducted on regular schedule.

( c ) Heaters which are not dependent on the combustion process within the heating unit may be used within the confines of processing buildings, orcompartments, if provided with temperature and safety controls and located away from combustible materials and the finished product.

(4) Bulk delivery and mixing vehicles. (i) The design of vehicles shall complywith the requirements of this subdivision.

( a ) Vehicles used over public highways for the bulk transportation of water gels or of ingredients classified as dangerous commodities, shall meet the requirements of the Department ofTransportation and shall meet the requirements of paragraphs (d) and (g)(6) of this section.

( b ) When electric power is supplied bya self-contained motor generator located on the vehicle the generator shall be at a point separate from where the water gel is discharged.

( c ) The design of processing equipment and general requirements shall conform to subparagraphs (3) (iii) and (iv) of this paragraph.

( d ) A positive action parking brake,
which will set the wheel brakes on atleast one axle shall be provided on vehicles when equipped with air brakes and shall be used during bulk deliveryoperations. Wheel chocks shall supplement parking brakes whenever conditions may require.

(ii) Operation of bulk delivery and mixing vehicles shall comply with the requirements of this subdivision.

( a ) The placarding requirements contained in DOT regulations apply to vehicles carrying water gel explosives or blasting agents.

( b ) The operator shall be trained inthe safe operation of the vehicle together with its mixing, conveying, and related equipment. He shall be familiar with the commodities being delivered and the general procedure for handling emergency situations.

( c ) The hauling of either blasting caps or other explosives, but not both,shall be permitted on bulk trucks provided that a special wood or nonferrous-lined container is installed for the explosives. Such blasting caps orother explosives shall be in DOT-specified shipping containers; see 49 CFR chapter I.

( d ) No person shall be allowed tosmoke, carry matches or any flameproducing device, or carry any firearmswhile in or about bulk vehicles effecting the mixing, transfer, or down-thehole loading of water gels at or near the blasting site.

( e ) Caution shall be exercised in themovement of the vehicle in the blasting area to avoid driving the vehicle over or dragging hoses over firing lines, cap wires, or explosive materials. The employer shall furnish the driver the assistance of a second person to guide the driver’s movements.

(f

) No intransit mixing of materials shall be performed.

( g ) The location chosen for water gel or ingredient transfer from a supportvehicle into the borehole loading vehicle shall be away from the blasthole


### 304 29 CFR Ch. XVII (7–1–15 Edition) § 1910.109

site when the boreholes are loaded or in the process of being loaded.

(i) Storage of ammonium nitrate—(1) Scope and definitions. (i)( a ) Except as provided in paragraph (i)(1)(i)( d ) of thisparagraph applies to the storage of ammonium nitrate in the form of crystals,flakes, grains, or prills including fertilizer grade, dynamite grade, nitrous oxide grade, technical grade, and other mixtures containing 60 percent or more ammonium nitrate by weight but does not apply to blasting agents.

( b ) This paragraph does not apply tothe transportation of ammonium nitrate.

( c ) This paragraph does not apply to storage under the jurisdiction of and in compliance with the regulations of the U.S. Coast Guard (see 46 CFR parts 146– 149).

( d ) The storage of ammonium nitrate and ammonium nitrate mixtures that are more sensitive than allowed by the‘‘Definition of Test Procedures for Ammonium Nitrate Fertilizer’’ is prohibited.

(ii)( a ) [Reserved] ( b ) The standards for ammonium nitrate (nitrous oxide grade) are thosefound in the ‘‘Specifications, Properties, and Recommendations for Packaging, Transportation, Storage, and Use of Ammonium Nitrate’’, available from the Compressed Gas Association, Inc., which is incorporated by reference as specified in §1910.6.

(2) General provisions. (i) This paragraph applies to all persons storing, having, or keeping ammonium nitrate,and to the owner or lessee of any building, premises, or structure in whichammonium nitrate is stored in quantities of 1,000 pounds or more.

(ii) Approval of large quantity storage shall be subject to due consideration of the fire and explosion hazards, including exposure to toxic vaporsfrom burning or decomposing ammonium nitrate.

(iii)( a ) Storage buildings shall not have basements unless the basements are open on at least one side. Storage buildings shall not be over one story in height.

( b ) Storage buildings shall have adequate ventilation or be of a construction that will be self-ventilating in the event of fire. ( c ) The wall on the exposed side of a storage building within 50 feet of a combustible building, forest, piles of
combustible materials and similar exposure hazards shall be of fire-resistive
construction. In lieu of the fire-resistive wall, other suitable means of exposure protection such as a free standing wall may be used. The roof coverings shall be Class C or better, as defined in the Manual on Roof Coverings, NFPA203M–1970, which is incorporated by reference as specified in §1910.6.

( d ) All flooring in storage and handling areas, shall be of noncombustiblematerial or protected against impregnation by ammonium nitrate and shall be without open drains, traps, tunnels, pits, or pockets into which any molten
ammonium nitrate could flow and be
confined in the event of fire.

( e ) The continued use of an existing storage building or structure not in strict conformity with this paragraph may be approved in cases where such
continued use will not constitute a
hazard to life.

(f

) Buildings and structures shall be dry and free from water seepage through the roof, walls, and floors.

(3) Storage of ammonium nitrate in bags, drums, or other containers. (i)( a )Bags and containers used for ammonium nitrate must comply with specifications and standards required for use in interstate commerce (see 49 CFR chapter I).

( b ) Containers used on the premisesin the actual manufacturing or processing need not comply with provisions of paragraph (i)(3)(i)( a ) of this paragraph.

(ii)( a ) Containers of ammonium nitrate shall not be accepted for storagewhen the temperature of the ammonium nitrate exceeds 130 ° F.

( b ) Bags of ammonium nitrate shall not be stored within 30 inches of the storage building walls and partitions.

( c ) The height of piles shall not exceed 20 feet. The width of piles shall not exceed 20 feet and the length 50 feet except that where the building is ofnoncombustible construction or is protected by automatic sprinklers the length of piles shall not be limited. In no case shall the ammonium nitrate be stacked closer than 36 inches below the


### 305 Occupational Safety and Health Admin., Labor § 1910.109

roof or supporting and spreader beams overhead.

( d ) Aisles shall be provided to separate piles by a clear space of not lessthan 3 feet in width. At least one service or main aisle in the storage area shall be not less than 4 feet in width.

(4) Storage of bulk ammonium nitrate. (i)( a ) Warehouses shall have adequate ventilation or be capable of adequate ventilation in case of fire.

( b ) Unless constructed of noncombustible material or unless adequate facilities for fighting a roof fire are available, bulk storage structures shall not exceed a height of 40 feet.

(ii)( a ) Bins shall be clean and free ofmaterials which may contaminate ammonium nitrate.

( b ) Due to the corrosive and reactive properties of ammonium nitrate, and to avoid contamination, galvanized iron, copper, lead, and zinc shall not beused in a bin construction unless suitably protected. Aluminum bins andwooden bins protected against impregnation by ammonium nitrate are permissible. The partitions dividing the ammonium nitrate storage from other products which would contaminate the ammonium nitrate shall be of tight construction.

( c ) The ammonium nitrate storage bins or piles shall be clearly identified by signs reading ‘‘Ammonium Nitrate’’ with letters at least 2 inches high.

(iii)( a ) Piles or bins shall be so sized and arranged that all material in the pile is moved out periodically in order to minimize possible caking of the stored ammonium nitrate.

( b ) Height or depth of piles shall belimited by the pressure-setting tendency of the product. However, in no case shall the ammonium nitrate be piled higher at any point than 36 inches below the roof or supporting and spreader beams overhead.

( c ) Ammonium nitrate shall not beaccepted for storage when the temperature of the product exceeds 130 ° F.

( d ) Dynamite, other explosives, and blasting agents shall not be used to break up or loosen caked ammonium nitrate.

(5) Contaminants. (i)( a ) Ammonium nitrate shall be in a separate building or shall be separated by approved typefirewalls of not less than 1 hour fire-resistance rating from storage of organic chemicals, acids, or other corrosive materials, materials that may require blasting during processing or handling,compressed flammable gases, flammable and combustible materials orother contaminating substances, including but not limited to animal fats, baled cotton, baled rags, baled scrappaper, bleaching powder, burlap or cotton bags, caustic soda, coal, coke, charcoal, cork, camphor, excelsior, fibers ofany kind, fish oils, fish meal, foam rubber, hay, lubricating oil, linseed oil, orother oxidizable or drying oils, naphthalene, oakum, oiled clothing, oiledpaper, oiled textiles, paint, straw, sawdust, wood shavings, or vegetable oils.
Walls referred to in this subdivision need extend only to the underside of
the roof.

( b ) In lieu of separation walls, ammonium nitrate may be separated from the materials referred to in paragraph ( a ) of this section by a space of at least
30 feet.

( c ) Flammable liquids such as gasoline, kerosene, solvents, and light fuel oils shall not be stored on the premises except when such storage conforms to §1910.106, and when walls and sills or curbs are provided in accordance with paragraphs (i)(5)(i) ( a ) or ( b ) of this section.

( d ) LP-Gas shall not be stored on thepremises except when such storage conforms to §1910.110.

(ii)( a ) Sulfur and finely divided metals shall not be stored in the samebuilding with ammonium nitrate except when such storage conforms toparagraphs (a) through (h) of this section.

( b ) Explosives and blasting agents shall not be stored in the same building with ammonium nitrate except on the premises of makers, distributors, and user-compounders of explosives or blasting agents.

( c ) Where explosives or blasting agents are stored in separate buildings, other than on the premises of makers, distributors, and user-compounders of explosives or blasting agents, they shall be separated from the ammoniumnitrate by the distances and/or barricades specified in Table H–22 of this subpart, but by not less than 50 feet.


### 306 29 CFR Ch. XVII (7–1–15 Edition) § 1910.109

( d ) Storage and/or operations on the premises of makers, distributors, and user-compounders of explosives or blasting agents shall be in conformity with paragraphs (a) through (h) of this
section.

(6) General precautions. (i) Electrical
installations shall conform to the requirements of subpart S of this part, for ordinary locations. They shall bedesigned to minimize damage from corrosion.

(ii) In areas where lightning storms are prevalent, lightning protection shall be provided. (See the Lightning Protection Code, NFPA 78–1968, whichis incorporated by reference as specified in §1910.6.)

(iii) Provisions shall be made to prevent unauthorized personnel from entering the ammonium nitrate storage

area.

(7) Fire protection. (i) Not more than2,500 tons (2270 tonnes) of bagged ammonium nitrate shall be stored in a building or structure not equipped withan automatic sprinkler system. Sprinkler systems shall be of the approved type and installed in accordance with §1910.159.

(ii)( a ) Suitable fire control devicessuch as small hose or portable fire extinguishers shall be provided throughout the warehouse and in the loadingand unloading areas. Suitable fire control devices shall comply with the requirements of §§1910.157 and 1910.158.

( b ) Water supplies and fire hydrants shall be available in accordance with recognized good practices.

(j) Small arms ammunition, small arms primers, and small arms propellants—(1) Scope. This paragraph does not apply to in-process storage and intraplant transportation during manufacture of small arms ammunition, small arms primers, and smokeless propellants.

(2) Small arms ammunition. (i) No quantity limitations are imposed on the storage of small arms ammunition in warehouses, retail stores, and other general occupancy facilities, except those imposed by limitations of storage facilities.

(ii) Small arms ammunition shall be separated from flammable liquids, flammable solids as classified in 49CFR part 172, and from oxidizing materials, by a fire-resistive wall of 1-hour rating or by a distance of 25 feet.

(iii) Small arms ammunition shall not be stored together with Class A or Class B explosives unless the storagefacility is adequate for this latter storage.

(3) Smokeless propellants. (i) All smokeless propellants shall be stored in shipping containers specified in 49 CFR 173.93 for smokeless propellants.

(ii) [Reserved] (iii) Commercial stocks of smokeless propellants over 20 pounds and not more than 100 pounds shall be stored in portable wooden boxes having walls of at least 1 inch nominal thickness.

(iv) Commercial stocks in quantities not to exceed 750 pounds shall be stored in nonportable storage cabinets having wooden walls of at least 1 inch nominal thickness. Not more than 400 pounds shall be permitted in any one cabinet.

(v) Quantities in excess of 750 poundsshall be stored in magazines in accordance with paragraph (c) of this section.

(4) Small arms ammunition primers. (i) Small arms ammunition primers shall not be stored except in the original shipping container in accordance with the requirements of 49 CFR 173.107 for small arms ammunition primers.

(ii) [Reserved] (iii) Small arms ammunition primersshall be separated from flammable liquids, flammable solids as classified in49 CFR part 172, and oxidizing materials by a fire-resistive wall of 1-hour rating or by a distance of 25 feet.

(iv) Not more than 750,000 small arms ammunition primers shall be stored in any one building, except as provided in paragraph (j)(4)(v) of this paragraph. Not more than 100,000 shall be stored in any one pile. Piles shall be at least 15 feet apart.

(v) Quantities of small arms ammunition primers in excess of 750,000 shall be stored in magazines in accordance with paragraph (c) of this section.

(k) Scope. (1) This section applies to the manufacture, keeping, having, storage, sale, transportation, and useof explosives, blasting agents, and pyrotechnics. The section does not apply to the sale and use (public display) ofpyrotechnics, commonly known as fireworks, nor the use of explosives in the


### 307 Occupational Safety and Health Admin., Labor § 1910.110

form prescribed by the official U.S. Pharmacopeia.

(2) The manufacture of explosives asdefined in paragraph (a)(3) of this section shall also meet the requirements contained in §1910.119.

(3) The manufacture of pyrotechnics as defined in paragraph (a)(10) of thissection shall also meet the requirements contained in §1910.119.

[39 FR 23502, June 27, 1974, as amended at 43 FR 49747, Oct. 24, 1978; 45 FR 60704, Sept. 12, 1980; 53 FR 12122, Apr. 12, 1988; 57 FR 6403, Feb. 24, 1992; 58 FR 35309, June 30, 1993; 61 FR 9237, Mar. 7, 1996; 63 FR 33466, June 18, 1998]

§ 1910.110 Storage and handling of liquefied petroleum gases.

(a) Definitions applicable to this section. As used in this section:

(1) API-ASME container—A container constructed in accordance with the requirements of paragraph (b)(3)(iii) of this section.

(2) ASME container—A containerconstructed in accordance with the requirements of paragraph (b)(3)(i) of this section.

(3) Container assembly—An assembly consisting essentially of the container and fittings for all container openings, including shutoff valves, excess flow valves, liquid-level gaging devices, safety relief devices, and protective housing.

(4) Containers—All vessels, such as tanks, cylinders, or drums, used fortransportation or storing liquefied petroleum gases.

(5) DOT—Department of Transportation.

(6) DOT container—A container constructed in accordance with the applicable requirements of 49 CFR chapter 1.

(7) ‘‘Liquified petroleum gases’’— ‘‘LPG’’ and ‘‘LP-Gas’’—Any material which is composed predominantly of any of the following hydrocarbons, or mixtures of them; propane, propylene, butanes (normal butane or iso-butane), and butylenes.

(8) Movable fuel storage tenders or farm carts—Containers not in excess of 1,200 gallons water capacity, equippedwith wheels to be towed from one location of usage to another. They are basically nonhighway vehicles, but may occasionally be moved over public roads or highways. They are used as a fuel supply for farm tractors, construction machinery and similar equipment.

(9) P.S.I.G.—pounds per square inch

gauge.

(10) P.S.I.A.—pounds per square inch absolute.

(11) Systems—an assembly of equipment consisting essentially of the container or containers, major devices such as vaporizers, safety relief valves,excess flow valves, regulators, and piping connecting such parts.

(12) Vaporizer-burner—an integral vaporizer-burner unit, dependent upon the heat generated by the burner as the source of heat to vaporize the liquid used for dehydrators or dryers.

(13) Ventilation, adequate—whenspecified for the prevention of fire during normal operation, ventilation shallbe considered adequate when the concentration of the gas in a gas-air mixture does not exceed 25 percent of the lower flammable limit.

(14) Approved—unless otherwise indicated, listing or approval by a nationally recognized testing laboratory.Refer to §1910.7 for definition of nationally recognized testing laboratory.

(15) Listed—see ‘‘approved’’ in §1910.110(14).

(16) DOT Specifications—regulations of the Department of Transportation published in 49 CFR chapter I.

(17)–(18) [Reserved](19) DOT cylinders—cylinders meeting the requirements of 49 CFR chapter
I. (b) Basic rules—(1) Odorizing gases. (i) All liquefied petroleum gases shall be effectively odorized by an approved agent of such character as to indicatepositively, by distinct odor, the presence of gas down to concentration in air of not over one-fifth the lower limit of flammability. Odorization, however, is not required if harmful in the use offurther processing of the liquefied petroleum gas, or if odorization will serve no useful purpose as a warning agent in such use or further processing.

(ii) The odorization requirement of paragraph (b)(1)(i) of this section shall be considered to be met by the use of 1.0 pounds of ethyl mercaptan, 1.0 pounds of thiophane or 1.4 pounds of amyl mercaptan per 10,000 gallons of LP-Gas. However, this listing of