Utah Admin. Code 614-4-18

Current through Bulletin 2024-12, June 15, 2024

Section R614-4-18 - Use of Explosives and Blasting Agents

A. General Provision

1. 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 except for ignition purposes. No person shall be allowed to handle explosives while under the influence of intoxicating liquors, narcotics, or other dangerous drugs.

2. Original containers or approved magazines shall be used for taking detonators and other explosives from storage magazines to the blasting area.

3. 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 mat constructed so that it is capable of preventing fragments from being thrown.

4. 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 all employees.

5. Surface blasting operations, except during unusual conditions shall be conducted during daylight hours.

a. Unusual blasting operations associated with industrial processes that are performed inside buildings shall be permitted, regardless of time of day, if both of the following conditions are met:

(1) All requirements concerning the use of explosives during normal blasting operations are implemented; and

(2) A minimum illumination intensity of 20 foot-candles is provided within a 5-foot (1.52m) radius of where explosive charges are being assembled, where explosive charges are being placed, and where explosive materials are being attached to initiating devices.

6. 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 representatives of 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.

7. Due precautions shall be taken to 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; and

b. The posting of signs warning against the use of mobile radio transmitters. (See ANSI C-95.4 and Institute of Makers of Explosive Safety Library Publication #20.)

8. Warning signs, indicating a blast area, shall be maintained at all approaches to the blast area. The warning sign lettering shall not be less than 4 inches in height on a contrasting background.

9. The blaster shall keep an accurate, up-to-date record of explosives, explosive materials, blasting agents, and blasting supplies used in a blast and shall keep an accurate running inventory of all explosives and blasting agents stored on the operation.

10. No activity of any nature other than that which is required for drilling or for loading holes with explosive material shall be permitted in a blast area.

11. Empty boxes and paper and fiber packing materials which have previously contained explosive material shall not be used again for any purpose, but shall be destroyed by burning at an approved isolated location out of doors, and no person shall be nearer than 100 feet after the burning has started.

12. Containers of explosives shall not be left open 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 metallic slitters may be used for opening fiberboard cases.

13. Explosives or blasting equipment that are deteriorated or damaged shall not be used.

14. No explosives shall be abandoned.

B. Blaster Qualifications.

1. A blaster shall be able to understand and give written and oral orders.

2. A blaster shall be qualified by reason of training, knowledge, or experience, in the field of transporting, storing, handling, and use of explosives material and have a working knowledge of State and local laws and regulations which pertain to explosives material.

3. Blasters shall be required to furnish satisfactory evidence of competency in handling explosives material and performing in a safe manner the type of blasting that will be required.

4. The blaster shall be knowledgeable and competent in the use of each type of blasting method used.

C. Loading of Explosive Materials.

1. Procedures that permit safe loading shall be established and followed.

2. All drill holes shall be sufficiently large to admit freely the insertion of the cartridges of explosives.

3. Tamping shall be done only with wood rods or plastic tamping poles without exposed metal parts, but nonsparking metal connectors may be used for jointed poles. Violent tamping shall be avoided. The primer shall never be tamped.

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

5. No holes shall be loaded except those to be fired in the next round of blasting.

6. No loaded holes shall be left unattended or unprotected.

7. Drilling shall not be started until all remaining butts of old holes are examined for unexploded charges, and if any are found, they shall be refired before work proceeds.

8. No employee shall be allowed to deepen drill holes which have contained explosives.

9. 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.

D. Initiation of Explosive Charges - Electric Blasting.

1. Electric blasting caps shall not be used where sources of extraneous electricity make the use of electric blasting caps dangerous. Blasting cap leg wires shall be kept short-circuited (shunted) until they are connected into the circuit for firing.

2. Before adopting any system of electrical firing, the blaster shall conduct a thorough survey for extraneous currents, and all dangerous currents shall be eliminated before any holes are loaded.

3. In any single blast using electric blasting caps, all caps shall be electrically compatible.

4. Electric blasting shall be carried out by using blasting circuits or power circuits in accordance with the electric blasting cap manufacturer's recommendations.

5. When firing a circuit of electric blasting caps, care must be exercised to ensure that an adequate quantity of delivered current is available, in accordance with the manufacturer's recommendations.

6. Connecting wires and lead wires shall be insulated single solid wires of sufficient current- carrying capacity.

7. Buss wires shall be solid single wires of sufficient current-carrying capacity.

8. When firing electrically, the insulation on all firing lines shall be adequate in good condition.

9. A power circuit used for firing electric blasting caps shall not be grounded.

10. In underground operations when firing from a power circuit, a safety switch shall be placed in the permanent firing line at intervals. This switch shall be made so it can be locked only in the "off" position and shall be provided with a short-circuiting arrangement of the firing lines to the cap circuit.

11. In underground operations there shall be a "lightning" gap of at least 15 feet in the firing system ahead of the main firing switch; that is, between this switch and the source of power. This gap shall be bridged by a flexible jumper cord just before firing the blast.

12. When firing from a power circuit, the firing switch shall be locked in the open or "off" position at all times, except when firing. It shall be so designed that the firing lines to the cap circuit are automatically short- circuited when the switch is in the "off" position. Keys to this switch shall be entrusted only to the blaster.

13. Blasting machines shall be in good condition and the efficiency of the machine shall be tested periodically to make certain that it can deliver power at its rated capacity.

14. When firing with blasting machines, the connections shall be made as recommended by the manufacturer of the electric blasting caps used.

15. The number of electric blasting caps connected to a blasting machine shall not be in excess of its rated capacity. Furthermore, in primary blasting, a series circuit shall contain no more caps than the limits recommended by the manufacturer of the electric blasting caps in use.

16. The blaster shall be in charge of the blasting machines and no other person shall connect the leading wires to the machines.

17. Blasters, when testing initiating circuits, or electric caps, shall use only blasting galvanometers or other instruments which have been designed and approved for this purpose.

18. Whenever the possibility exists that a leading line of blasting wire might be thrown over a live powerline by the force of an explosion, care shall be taken to see that the total length of wires are kept too short to hit the lines, or that the wires are securely anchored to the ground. If neither of these requirements can be satisfied, a nonelectric system shall be used.

19. In electrical firing, only the employee making leading wire connections shall fire the shot. All connections shall be made from the bore hole back to the source of firing current, and the leading wires shall remain shorted and not be connected to the blasting machine or other source of current until the charge is to be fired.

20. After firing an electric blast from a blasting machine the leading wires shall be immediately disconnected from the machine and short-circuited.

E. Use of Safety Fuse.

1. Safety fuse shall only be used where sources of extraneous electricity make the use of electric blasting caps dangerous. The use of a fuse that has been damaged in any way shall be forbidden.

2. The hanging of a fuse on nails or other projections which will cause a sharp end to be formed in the fuse is prohibited.

3. Before capping safety fuse, a short length shall be cut from the end of the supply reel so as to assure a fresh cut end in each blasting cap.

4. Only a cap crimper of approved design shall be used for attaching blasting caps to safety fuse. Crimpers shall be kept in good repair and accessible for use.

5. No unused cap or short capped fuse shall be placed in any hole to be blasted; such detonators shall be removed from the working place and destroyed.

6. No fuse shall be capped, or primers made up, in any magazine or near any possible source of ignition.

7. No employees shall be permitted to carry detonators or store detonators or primers of any kind in their clothing.

8. The minimum length of safety fuse to be used in blasting shall not be less than 36 inches or a burning time of 120 seconds.

9. At least two employees shall be present when multiple cap and fuse blasting is done by hand lighting methods.

10. Not more than 12 fuses shall be lighted by each blaster when hand lighting devices are used. However, when two or more safety fuses in a group are lighted as one by means of igniter cord, or other similar fuse lighting devices, they may be considered as one fuse.

11. The method of dropping or pushing a primer or any explosive with a lighted fuse attached is forbidden.

12. Cap and fuse shall not be used for firing mudcap charges unless charges are separated sufficiently to prevent one charge from dislodging other shots in the blast.

13. When blasting with safety fuses, consideration shall be given to the length and burning rate of the fuse. Sufficient time, with a margin of safety, shall always be provided for the blaster to reach a place of safety.

F. Use of Detonating Cord.

1. Care shall be taken to select a detonating cord consistent with the type and physical condition of the bore hole and stemming and the type of explosives used.

2. Detonating cord shall be handled and used with the same respect and care given other explosives.

3. The line of detonating cord extending out of a bore hole or from a charge shall be cut from the supply spool before loading the remainder of the bore hole or placing additional charges.

4. Detonating cord shall be handled and used with care to avoid damaging or severing the cord during and after loading and hooking up.

5. Detonating cord connections shall be complete and positive in accordance with approved and recommended methods. Knot-type or other cord-to-cord connections shall be made only with detonating cord in which the explosive core is dry.

6. All detonating cord trunklines and branchlines shall be free of loops, sharp kinks, or angles that direct the cord back toward the oncoming line of detonation.

7. All detonating cord connections shall be inspected before firing the blast.

8. When detonating cord millisecond-delay connectors or short-interval delay electric blasting caps are used with detonating cord, the practice shall conform strictly to the manufacturer's recommendations.

9. When connecting a blasting cap or an electric blasting cap to detonating cord, the cap shall be taped or otherwise attached securely along the side or the end of the detonating cord, with the end of the cap containing the explosive charge pointed in the direction in which the detonation is to proceed.

10. Detonators for firing the trunkline shall not be brought to the loading areas nor attached to the detonating cord until everything else is in readiness for the blast.

G. Firing the Blast.

1. Before a blast is fired, a warning signal shall be given by the blaster in charge, who has made certain that all surplus explosives are in safe place and all employees, vehicles, and equipment are at a safe distance, or under sufficient cover.

2. Before firing any blast, warning shall be given, and all possible entries into the blasting area, shall be carefully guarded. The blaster shall make sure that all employees are out of the blast area before firing a blast.

H. Inspection After Blasting.

1. Immediately after the blast has been fired, the firing line shall be disconnected from the blasting machine, or where power switches are used, they shall be locked open or in the off position.

2. Sufficient time shall be allowed for the smoke and fumes to leave the blast area before returning to the shot. An inspection of the area and the surrounding rubble shall be made by the blaster to determine if all charges have been exploded before employees are allowed to return to the operation. Any unexploded explosives shall be disposed of safely.

I. Misfires.

1. If a misfire is found, the blaster shall provide proper safeguards for excluding all employees from the danger zone.

2. No other work shall be done except that necessary to remove the hazard of misfire and only those employees necessary to do the work shall remain in the danger zone.

3. No attempt shall be made to extract explosives from any charged or misfired hole; a new primer shall be put in and the hole refired. If refiring of the misfired hole presents a hazard, the explosives may be removed by washing out with water or, where the misfire is under water, blown out with air.

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

5. No drilling, digging, or picking shall be permitted until all missed holes have been detonated or the authorized representative has approved the work can proceed.

J. Underwater Blasting.

1. Loading tubes and casings of dissimilar metals shall not be used because of possible electric transient currents from galvanic action of the metals and water.

2. Only water-resistant blasting caps and detonating cords shall be used for all marine blasting. Loading shall be done through a non-sparking metal loading tube when tube is necessary.

3. No blast shall be fired while any vessel under way is closer than 1,500 feet to the blasting area. Those on board vessels or craft moored or anchored within 1,500 feet shall be notified before a blast is fired.

4. No blast shall be fired while any swimming or diving operations are in progress in the vicinity of the blasting area. If such operations are in progress, signals and arrangements shall be agreed upon to assure that no blast shall be fired while any person is in the water.

5. Blasting flags shall be displayed.

6. The storage and handling of explosives aboard vessels used in underwater blasting operations shall be according to provisions outlined herein on handling and storing explosives.

7. When more than one charge is placed under water, a float device shall be attached to an element of each charge in such a manner that it will be released by the firing. Misfires shall be handled in accordance with the requirements of R614-4-18.I.

Utah Admin. Code R614-4-18