Utah Admin. Code 614-4-14

Current through Bulletin 2024-12, June 15, 2024

Section R614-4-14 - Blasting Agents

A. General. Unless otherwise set forth in this rule, blasting agents, excluding slurry, water gels, and emulsions, shall be manufactured, transported, stored, and used in accordance with these regulations. Slurry, water gels, and emulsion are covered in R614-4.

B. Fixed Location Mixing.

1. Buildings or other facilities used for the mixing of blasting agents shall conform to the following minimum requirements.

2. Buildings shall be of noncombustible construction or sheet metal on wood studs.

3. Floors shall be of concrete or other non-absorbent material. They shall be constructed without enclosed floor drains and piping into which molten materials could flow and be confined in case of fire.

4. All fuel oil storage facilities, including heating oil and process oil, 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, or diked in a manner to contain the tank contents in case of rupture.

5. The building shall be well ventilated (See R614-4-5.C.)

6. Only heating units which do not depend on combustion processes, properly designed and located, may be used in the plant. Electric heaters with exposed resistance elements are prohibited. All direct sources of heat shall be provided from units located outside the mixing building.

7. All internal-combustion engines, such as diesel or gasoline-powered generators, shall be located outside the mixing building, or shall be properly ventilated and isolated by a permanent firewall. The exhaust systems on all such engines shall be provided with spark arrester mufflers, or be remotely located, so that any spark emission will not be a hazard to any materials in or adjacent to the building.

C. Equipment used for mixing blasting agents shall conform to the requirements of this subdivision.

1. The design of the processing equipment, including mixing and conveying equipment, shall be compatible with the relative sensitivity of the materials being handled. Equipment shall be designed to minimize the possibility of frictional heating, compaction, overloading, accumulation of dust, and confinement. All bearings and drive assemblies shall be mounted outside the mixer. All surfaces shall be accessible for cleaning. All hollow shafts shall be constructed to permit venting with an opening of at least 1/2 inch diameter.

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

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

4. All electrical equipment, including wiring, switches, controls, motors and lights which is located inside the mixing room shall conform to the requirements of 29 CFR 1910 Subpart S for Class II, Division 2 locations.

5. Mixing and packaging equipment shall be constructed of materials compatible with the materials being handled.

6. Suitable means shall be provided to prevent the flow of fuel to the mixer in case of fire. In gravity flow systems, an automatic spring-loaded shut-off valve with fusible link shall be installed.

D. The provisions of this subdivision shall be considered when determining blasting agent compositions.

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

2. Oxidizers of small particle size, such as crushed ammonium nitrate prills or fines, may be more sensitive than coarser products and shall, therefore, be handled with greater care.

3. No hydrocarbon liquid fuel with flashpoint lower than that of no. 2 diesel fuel oil 125 degrees F. minimum shall be used.

4. Crude oil and crankcase oil shall not be used.

5. Metal powders such as aluminum shall be kept dry and shall be stored on containers or bins which are moisture-resistant or weather-tight. Solid fuels shall be used in such manner as to minimize dust explosion hazards.

6. Peroxides and chlorates shall not be used.

E. Mixing Operations

1. Safety precautions at mixing plants shall include the requirements of this subdivision.

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

3. A daily visual inspection shall be made of the mixing, conveying and electrical equipment to determine that such equipment is in safe operating condition. All discrepancies shall be corrected prior to operation. A program of systematic maintenance shall be conducted on a regular schedule.

4. The entire mixing and packaging plant shall be cleaned regularly and thoroughly to prevent excessive accumulation of dust, grease, and product ingredients.

5. Empty ingredient bags shall be disposed of daily in a safe manner.

6. No welding shall be permitted nor open flames allowed in or around the mixing or storage area of the plant, unless the equipment and area have been completely washed down and all fuels and oxidizing material removed.

7. Before welding or making repairs to hollow shafts, all fuels and oxidizing material shall be removed from the outside and inside of the shaft by a thorough washing, and the shaft shall be vented.

8. Other explosive material shall not be stored inside of or within 50 feet of any building or facility used for the mixing of blasting agents.

F. Bulk delivery and mixing vehicles.

1. The provisions of this subparagraph shall apply to off-highway private operations as well as to all public highway movements.

2. A bulk vehicle body for delivering and mixing blasting agents shall conform with the requirements of this subdivision.

a. The body shall be constructed of noncombustible materials.

b. Vehicles used to transport bulk premixing 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 which contact the product shall have outboard bearings with 1-inch minimum clearance between the bearings and the outside of the product container. Particular attention shall be given to the clearances on all moving parts.

d. A bulk delivery vehicle shall be strong enough to carry the load without difficulty and be in safe mechanical condition.

e. When electric power is supplied by a self-contained motor generator located on the vehicle, the motor generator shall be separated from the blasting agent discharge.

f. A positive action parking brake which will set the wheel brakes on at least one axle shall be provided on vehicles when equipped with air brakes and shall be used during bulk delivery operations. Wheel chocks shall supplement parking brakes whenever conditions may require.

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

a. The operator shall be trained in the 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 operator shall be familiar with applicable local, state, and federal laws and regulations governing the transportation of explosive materials to the location and on the site.

c. No person shall smoke, carry matches or any flame producing device, or carry any fire-arms while in or about bulk vehicles effecting the mixing, transfer, or down-the-hole loading of blasting agents at or near the blasting site.

d. Caution shall be exercised in the movement 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 of a second person to guide his movements.

e. No in transit mixing of materials shall be performed.

4. Pneumatic loading from bulk delivery vehicles into blast holes primed with electric blasting caps or other static-sensitive systems shall conform to the requirements of the 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 will adequately dissipate static under potential field conditions.

5. Repairs to bulk delivery vehicles shall conform to the requirements of this Part.

a. No welding or open flames shall be used on or around any part of the delivery equipment unless it has been completely 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.

G. Bulk Storage Bins

1. 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.

2. 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.

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

4. Any electrically driven conveyors for loading or unloading bins shall conform to the requirements of 29 CFR 1910 Subpart S. They shall be designed to minimize damage from corrosion.

5. Bins containing blasting agent shall be located, with respect to inhabited buildings, passenger railroads, and public highways, in accordance with American Table of Distances and separation from other blasting agent storage and explosives storage shall be in conformity with NFPA 492.

6. Bins containing ammonium nitrate shall be separate from blasting agent storage and explosives storage in conformity with NFPA 492.

H. Storage of Blasting Agents shall conform with the requirements of R614-4-12.

I. Transportation of Blasting Agents shall conform with the requirements of R614-4-13.

Utah Admin. Code R614-4-14