17 October 2015

SAFETY IN THE TRANSPORTATION, STORAGE, HANDLING AND USE OF

EXPLOSIVE MATERIALS

MEMBER COMPANIES (As of October 2015)

Accurate Energetic Systems McEwen, Tennessee Austin Powder Company Cleveland, Ohio Baker Hughes Houston, Texas Davey Bickford North America Sandy, Utah Detotec North America, Inc. Sterling, Connecticut DYNAenergetics, US Inc Lakeway, Texas Dyno Nobel Inc. Salt Lake City, Utah General Dynamics – Munitions Services Joplin, Missouri GEODynamics, Inc. Millsap, Texas Hunting Titan Houston, Texas Jet Research Center/Halliburton Alvarado, Texas Maine Drilling & Blasting Auburn, New Hampshire Maxam North America, Inc. Salt Lake City, Utah MP Associates, Inc. Ione, California MuniRem Environmental LLC Athens, Georgia Nelson Brothers Birmingham, Alabama Nobel Insurance Services Dallas, Texas Orica USA Inc. Watkins, Colorado Owen Oil Tools LP Godley, Texas Safety Consulting Engineers, Inc. Schaumberg, Illinois

Secured Land Transport Glendale, Arizona Senex Explosives, Inc. Cuddy, Pennsylvania SLT Secured Systems International LLC Tolleson, AZ Special Devices, Inc. Mesa, Arizona Teledyne RISI Tracy, California Tread Corporation Roanoke, Virginia Tri-State Motor Transit Company Joplin, Missouri Vet’s Explosives, Inc. Torrington, Connecticut Visionary Solutions LLC Knoxville, Tennessee W.A. Murphy, Inc. El Monte, California

Liaison Class Members:

Canadian Explosives Industry Association (CEAEC) Ottawa, ONT, Canada

Federation of European Explosives Manufacturers Brussels, Belgium

International Society of Explosives Engineers (ISEE) Cleveland, Ohio

National Institute for Explosives Technology (NIXT) Lonehill, South Africa

SAFEX International (SAFEX) Blonay, Switzerland

Explosives Safety & Technology Society – Visfotak Maharashtra, India

Copyright © 2015 Institute of Makers of Explosives

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1120 NINETEENTH STREET, N.W. SUITE 310

WASHINGTON, DC 20036-3605 (202) 429-9280

www.ime.org info@ime.org

The Institute of Makers of Explosives (IME) is the safety association of the commercial explosives industry in the United States and Canada. The primary concern of IME is the safety and protection of employees, users, the public, and the environment in the manufacture, transportation, storage, handling, use, and disposal of commercial explosive materials.

Founded in 1913, IME was created to provide technically accurate information and recommendations concerning commercial explosive materials and to serve as a source of reliable data about their use. Committees of qualified representatives from IME member companies developed this information and significant portions of their recommendations are embodied in regulations of federal and state agencies.

The Institute’s principal committees are: Environmental Affairs; Legal Affairs; Safety and Health; Security; Technical; and Transportation and Distribution.

http://www.ime.org/mailto:info@ime.org

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TABLE OF CONTENTS

Page FOREWORD.................................................................................................................................v

DISCLAIMER............................................................................................................................. vi

GENERAL RECOMMENDATIONS .........................................................................................1

REGULATIONS ...........................................................................................................................2 A. Federal Agencies ................................................................................................................2 B. State and Local Agencies ...................................................................................................3

CLASSIFICATION OF EXPLOSIVE MATERIALS ..............................................................4 A. Current Classification Divisions ........................................................................................4 B. Prior Classification Divisions ............................................................................................4 C. Classification Divisions for Storage Purposes ...................................................................5

TRANSPORTATION ...................................................................................................................7

STORAGE .....................................................................................................................................7

COMMERCIAL EXPLOSIVE MATERIALS ..........................................................................8 A. Dynamite ............................................................................................................................8 B. Permissible Explosives ......................................................................................................9 C. Demil Explosives ...............................................................................................................9 D. Emulsions, Slurries and Water Gels ................................................................................10 E. Division 1.5 Materials (Blasting Agents) ........................................................................10 F. Boosters ...........................................................................................................................11 G. Initiation Components and Systems .................................................................................12

BLASTING MACHINES, TESTING MACHINES, AND ACCESSORIES .................................................................................................................17

A. Blasting Machines for Electric Detonators ......................................................................17 B. Shock Tube Starters .........................................................................................................18 C. Testing Equipment for Electric Detonators .....................................................................18 D. Electronic Detonator Blasting Accessories ......................................................................18 E. Other Accessories ............................................................................................................19

FIELD USE OF INITIATION SYSTEMS ...............................................................................19 A. Electric Detonators...........................................................................................................19 B. Electronic Detonators .......................................................................................................19 C. Nonelectric Detonators ....................................................................................................19

GROUND VIBRATION AND AIRBLAST ..............................................................................20 A. Ground Vibration .............................................................................................................20 B. Airblast .............................................................................................................................23 C. Conclusion ...................................................................................................................... 23

METAL/NONMETAL MINING ...............................................................................................24 A. Surface Operations ...........................................................................................................24 B. Underground Operations ..................................................................................................26

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COAL MINING ..........................................................................................................................29 A. Surface Operations ...........................................................................................................29 B. Underground Operations ..................................................................................................30 C. Misfires: Machine-Cut and Solid Shooting .....................................................................32

CONSTRUCTION ......................................................................................................................33 A. General .............................................................................................................................33 B. Surface .............................................................................................................................33 C. Underground ....................................................................................................................34

SEISMIC PROSPECTING ........................................................................................................34 A. General .............................................................................................................................34 B. Specific Recommendations ..............................................................................................34

COYOTE BLASTING ................................................................................................................35

AGRICULTURAL BLASTING ................................................................................................36 A. Stump Blasting .................................................................................................................36 B. Ditch Blasting ..................................................................................................................37 C. Pond Blasting ...................................................................................................................40 D. Boulder Blasting ..............................................................................................................40 E. Stemming .........................................................................................................................40

POST-BLAST INSPECTION WITH PRE-BLAST INFORMATION SURFACE OPERATIONS ........................................................................................................41

A. Pre-Blast Preparation .......................................................................................................41 B. Post-Blast Inspection .......................................................................................................42 C. Post-Blast Inspection Review ..........................................................................................42

MISFIRES ...................................................................................................................................43 A. Prevention Plan ............................................................................................................... 43 B. Waiting Period ................................................................................................................ 44 C. Misfire Resolution Procedures ........................................................................................ 44

FUMES ........................................................................................................................................47 A. Surface Blasting ...............................................................................................................47 B. Underground Blasting ......................................................................................................49

DRILLING ..................................................................................................................................49

ANNEX A - BLAST SITE CHECKLIST .................................................................................51 ANNEX A – POST-BLAST INSPECTION ..............................................................................52 ANNEX A – POST-BLAST INSPECTION REVIEW ............................................................53

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SLP-17 Safety in the Transportation, Storage, Handling and Use of Explosive Materials

FOREWORD

The Institute of Makers of Explosives distributed the first edition of this publication in 1932 to encourage and promote safe practices by the users of explosive materials. In the interim, revisions have been made to reflect new developments in products and procedures.

The current issue discusses not only dynamites, the commercial explosives that have been the standard of the industry for many years, but also slurries, water gels, emulsions, ANFO, cast boosters and the newest initiation systems. The latest addition to the document is a section on drilling.

The various applications of explosive materials are considered briefly with the safety considerations for each application being stressed.

The regulatory aspects for the safe, approved and legal manufacture, transportation, storage, handling and use of explosive materials are noted and appropriate regulations referenced.

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DISCLAIMER

Explosive materials are powerful tools which, when used properly, are literally capable of “moving mountains”. Improperly used by untrained or inexperienced persons, explosive materials can cause death, injury or property damage.

This publication outlines methods for the safe transportation, storage, handling and use of explosive materials. It is not intended to cover every situation or all of the many details of any particular situation that might possibly be encountered in the field. Such an endeavor is beyond the scope or intention of this publication.

The information contained in this publication is of a general nature and is based upon data developed through years of experience in the handling of explosive materials. Product literature and technical data sheets published by the manufacturers of explosive materials should be consulted for detailed information on the characteristics of a particular product and recommended applications for specific products.

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GENERAL RECOMMENDATIONS

To establish and maintain the highest safety standards in the handling of explosive materials, all phases concerning manufacturing, storage, transportation, and use must be accorded the same degree of consideration. Everyone involved with any aspect of explosives handling must realize that proper handling promotes safe handling.

At any operation where explosive materials are handled, an authorized person should be responsible for establishing and enforcing procedures to ensure that all safety precautions and regulatory requirements are being followed.

Personnel involved in explosives handling (manufacturing or mixing personnel, magazine keeper and magazine crews, truck drivers and helpers, blasters and loading crews) should all be familiar with the characteristics and hazards of the products they are handling and trained in proper handling procedures.

Reference materials on the handling of explosive materials are available from a number of sources, including:

Institute of Makers of Explosives (Safety Library Publications); National Safety Council (Data Sheets); Product data sheets and technical data sheets published by manufacturers of explosive materials; Case Inserts or Warnings (packed in cases or cartons of explosives materials); U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF); U.S. Bureau of Land Management (BLM) (Information Circulars, Reports of Investigation); National Institute for Occupational Safety and Health (NIOSH); U.S. Department of Transportation (DOT); U.S. Mine Safety and Health Administration (MSHA); U.S. Occupational Safety and Health Administration (OSHA); Office of Surface Mining (OSM); State and Local Explosive Regulatory Agencies; American National Standards Institute (ANSI); National Fire Protection Association (NFPA); International Association of Geophysical Contractors (IAGC); The American Welding Society (AWS); Institute of Electrical and Electronics Engineers (IEEE); and International Society of Explosives Engineers (ISEE).

Personnel assigned to explosives handling operations must be at least 18 years of age and physically and mentally able to perform the work required. They should be able to understand written and oral orders in the English language, and must not be addicted to alcohol, narcotics or dangerous substances. Additionally, truck drivers, persons in charge of storage magazines, or blasters must be at least 21 years of age. The person in charge of a particular operation must be familiar with all federal, state and local regulations pertaining to his or her particular area of responsibility and must have obtained all necessary licenses and permits required for these positions.

Explosive materials must be stored in magazines that are properly constructed and located in compliance with all federal, state and local regulations to minimize public exposure, prevent unauthorized access to dangerous products and reduce deterioration of the explosive materials.

Vehicles used for transporting explosive materials must be strong enough to carry the load and be in good mechanical condition.

Explosive materials should be transported in their original containers in “day boxes” or in enclosed vehicles. When open- bodied vehicles are used to transport explosive materials the explosive materials should be loaded into magazines or closed containers securely fastened to the truck bed. Detonators may be transported over public highways with other explosive materials on the same vehicle only in accordance with Title 49 Code of Federal Regulations—U.S. Department of Transportation.

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Smoking should not be permitted within 50 feet (ft) (15 meters [m]) of explosive materials nor should anyone working around explosive materials carry matches, lighters or flame producing devices (except that the blaster may possess a device for the specific purpose of lighting safety fuse).

The handling of all explosive materials should be discontinued during the approach and progress of a thunderstorm and all personnel should move to a safe location.

Explosive materials should not be carried in pockets of clothing or glove compartments of vehicles or left lying around unsecured or unguarded. Any explosive materials remaining from a loading operation should be promptly returned to the storage magazine.

Explosive materials that show leakage or deterioration should not be used and the manufacturer should be contacted for proper handling recommendations. Explosive materials should only be disposed of by competent personnel in accordance with the manufacturer's recommendations.

No persons should attempt to use explosive materials unless they are adequately trained and are fully aware of the nature and hazards of the materials they are handling.

REGULATIONS

Regulatory controls at the federal, state and local level concerning the manufacture, transportation, storage, sale, and use of explosive materials have and will continue to increase. Some agencies issue regulations that are concerned with protecting the public, while others are involved with the safety of the user, the protection of the environment or the prevention of the illegal sale and/or distribution of explosive materials. Although this publication will assist you in regulatory compliance, it does not contain all applicable regulatory criteria. Explosives users must make sure they know and comply with the regulations that apply to their particular operations. Agencies administering regulations that involve explosive materials are listed below:

A. Federal Agencies

1. Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) 2. Environmental Protection Agency (EPA) 3. Mine Safety and Health Administration (MSHA) 4. Occupational Safety and Health Administration (OSHA) 5. Office of Surface Mining (OSM) 6. United States Coast Guard (USCG) 7. United States Department of Transportation (DOT)

a. Federal Motor Carrier Safety Administration (FMSCA) b. Federal Aviation Administration (FAA) c. Federal Railroad Administration (FRA) d. Research and Special Programs Administration (RSPA)

B. State and Local Agencies

1. Department of Mining and Minerals 2. Department of Natural Resources 3. Department of Environmental Resources 4. Department of Energy 5. Fire Marshal 6. Department of Transportation 7. Department of Labor and Industry 8. Sheriff 9. State Police

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AREAS OF CONCERN, RESPONSIBILITY AND AUTHORITY ARE:

Area of Concern

Agency Responsibility Authority∗

Manufacture OSHA

ATF

MSHA

EPA

Safety & Health of Worker

Accountability (Identification and Record Keeping)

Permissibility

Waste Handling/Disposal, “Right-to-Know”, Discharges or Emission

29 CFR

27 CFR

30 CFR

40 CFR

Transportation DOT

OSHA

MSHA

USCG

EPA

Public Safety (All Modes)

Safety & Health of Worker (Construction & General Industry)

Safety & Health of Worker (Mines & Quarries)

Public Safety (Ports and Navigable Waters)

Waste Handling

49 CFR

29 CFR

30 CFR

46 CFR

40 CFR Storage ATF

EPA

Security (Accountability)

Waste Handling/Disposal, “Right-to-Know”

27 CFR

40 CFR Use MSHA

OSHA

OSM

EPA

Safety & Health of Worker (Mines & Quarries)

Safety & Health of Worker (Construction & General Industry)

Environment & Public Safety (Surface Coal Mines)

Waste Handling/Disposal, “Right-to-Know”, Discharges or Emissions

30 CFR

29 CFR

30 CFR

40 CFR

Miscellaneous State & Local

Agencies

All of the above Various state and local

regulations

∗ Reference Title Code of Federal Regulations. Available from the U.S. Superintendent of Documents, Government Printing Office, Washington, D.C. 20402

CLASSIFICATION OF EXPLOSIVE MATERIALS

For transportation purposes, explosives are classified by DOT in accordance with 49 CFR and under these regulations all explosives are listed as Hazard Class 1 materials. Class 1 materials are divided into six divisions to note the principal hazard of the explosive. These six divisions are as follows:

A. Current Classification Divisions

1. Division 1.1 Explosives that have a mass explosion hazard. A mass explosion is one which affects the entire load instantaneously. Typical examples: dynamite, detonator (cap) sensitive emulsions, slurries, water gels, cast boosters, and mass detonating detonators.

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2. Division 1.2 Explosives that have a projection hazard but not a mass explosion hazard. Typical examples: certain types of ammunition, mines, and grenades.

3. Division 1.3 Explosives that have a fire hazard and either a minor blast hazard or a minor projection hazard or both, but not a mass explosion hazard. Typical examples: certain types of fireworks, propellants, and pyrotechnics.

4. Division 1.4 Explosives that present a minor explosion hazard. The explosive effects are largely confined to the package and no projection of fragments of appreciable size or range is to be expected. An external fire must not cause virtually instantaneous explosion of almost the entire contents of the package. Typical examples: safety fuse and certain electric, electronic, and nonelectric detonators.

5. Division 1.5 Explosives that are very insensitive. This division is comprised of substances which have a mass explosion hazard but are so insensitive that there is very little probability of initiation or of transition from burning to detonation under normal conditions of transport. Typical examples: blasting agents, ANFO, non cap sensitive emulsions, blends, slurries, water gels, and other explosives that require a booster for initiation.

6. Division 1.6 Extremely insensitive explosives which do not have a mass explosive hazard. This division is comprised of articles which contain only extremely insensitive detonating substances and which demonstrate a negligible probability of accidental initiation or propagation. The risk from articles of Division 1.6 is limited to the explosion of a single article. Generally, commercial explosives are not classified as Division 1.6.

B. Prior Classification Divisions

Until October 1, 1991, DOT classified explosive materials as Explosives A, B, C, or Blasting Agent. Essentially, these classes were as follows:

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1. Class A Explosives Explosives that detonate or have maximum hazard. Typical examples: dynamites, cast boosters, cap sensitive emulsions, slurries, water gels, and certain initiators and detonators.

2. Class B Explosives Explosives that function by rapid combustion rather than detonation. Typical examples: pyrotechnics, certain propellants and fireworks, flash powders, and signal devices.

3. Class C Explosives Explosives which contain Class A or B explosives as components but in restricted quantities that present minimum hazard. Typical examples: safety fuse, igniter cord, certain detonators, and specialty explosive devices.

4. Blasting Agents Explosive materials that have been tested and found to be so insensitive that it is unlikely that they will initiate or detonate in a fire during normal transportation conditions. Typical examples: ANFO, blends, emulsions, slurries, and water gels that are not cap sensitive.

For comparing the old and new DOT classification systems, note the chart below:

CURRENT CLASSIFICATION PRIOR DOT CLASSIFICATION

Division 1.1 Class A Explosives

Division 1.2 Class A or Class B Explosives

Division 1.3 Class B Explosives

Division 1.4 Class C Explosives

Division 1.5 Blasting Agents

Division 1.6 No Applicable Hazard Class

C. Classification Divisions for Storage Purposes

For storage purposes, ATF separates explosives into three classes as follows:

1. High Explosives Explosive materials that can be caused to detonate by means of a blasting cap when unconfined, (for example, dynamite, flash powders, and bulk salutes). Typical examples: dynamites, cast boosters, and certain emulsions, slurries and water gels.

2. Low Explosives Explosive materials that can be caused to deflagrate when confined (for example, black powder, safety fuses, igniters, igniter cords, fuse lighters, and “display fireworks” classified as UN0333, UN0334, or UN0335 by the U.S. Department of Transportation regulations at 49 CFR 172.101, except for bulk salutes). Typical examples: black powder, safety fuse, igniters and fuse lighters.

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3. Blasting Agents Any material or mixture, consisting of fuel and oxidizer, that is intended for blasting and not otherwise defined as an explosive; if the finished product, as mixed for use or shipment, cannot be detonated by means of a number 8 test blasting cap when unconfined. A number 8 test blasting cap is one containing 2 grams (g) of a mixture of 80 percent mercury fulminate and 20 percent potassium chlorate, or a blasting cap of equivalent strength. An equivalent strength cap comprises 0.40-0.45 grams of PETN base charge pressed in an aluminum shell with bottom thickness not to exceed to 0.03 of an inch (in), to a specific gravity of not less than 1.4 g/cc, and primed with standard weights of primer depending on the manufacturer. Typical examples: ANFO, blends, and certain emulsions, slurries, and water gels.

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TRANSPORTATION

The commercial explosives industry is a global enterprise. These products and materials are shipped to and from the United States by a variety of modes, but within the United States, transportation is dominated by truck. When these materials are transported in intrastate, interstate, or foreign commerce within the United States, including loading, unloading, and storage incidental to the movement, they are subject to the regulations of the DOT found in Title 49 CFR. Transportation in commerce by truck includes any movement that utilizes or crosses a public road. Transportation that is entirely on private property in not considered “in commerce” and is not subject to the requirements of the HMR. Property is regarded as “private” if public access is legally and actually restricted from the area where transportation occurs.

In order to ensure the highest level of safety in the commercial transportation of explosives and other hazardous materials, Congress authorizes DOT to insist on a high degree of uniformity in the domestic regulation of this activity. DOT also works hard at the international level to harmonize domestic transport requirements with those of other countries so the safety is not compromised and that commerce is not unnecessarily impeded. Despite this high level of regulation, states, counties and cities sometimes impose additional or different requirements on the transportation of explosives. As a transporter of explosives, you should be aware of these local laws. In some cases, it may be impossible to comply with local laws and DOT's requirements or be less safe than complying with DOT regulations. (Refer to 49 CFR 107 Subpart C to determine if such non-federal rules are legal and what your options are for complying with these local requirements.)

When transporting explosives on private property, other federal regulatory agency rules apply. On mine sites (both surface and underground), the transporter should follow MSHA regulations prescribed in Title 30 CFR. Explosive materials hauled over general industrial and construction sites (underground or surface) are subject to OSHA regulations at Title 29 CFR. More complete coverage of the subject of transporting explosive materials can be found in:

IME Safety Library Publication Number 14, Handbook for the Transportation and Distribution of Explosive Materials; and

IME Safety Library Publication Number 22, Recommendations for the Safe Transportation of Detonators in a Vehicle with Certain Other Explosive Materials and Generic Loading Guide for the IME-22 Container.

STORAGE

All explosive materials, detonators (including electric, electronic, and nonelectric), detonating cord, shock tube, safety fuse, igniters, and squibs must be stored in magazines constructed and located in accordance with federal, state and local regulations. Magazines should be kept locked at all times except for inspection, inventory, or the movement of explosive materials in or out of the magazine.

Approved storage facilities are designed to prevent unauthorized persons from having access to the explosives and to protect the explosive materials from deterioration. Accordingly, magazine sites should be inspected frequently (at least every seven days). Accurate inventories should be kept of all explosive materials and stocks of older materials should be used first. Roofs, walls, doors, floors, locks and ventilators of magazines must be kept in good repair. The area inside the magazine should be kept clean and orderly. No combustible material should be stored within 50 feet (15.2 m) of the magazine and all dry grass or brush cleared for a distance of 25 feet (7.6 m) around the magazine.

Commerce in explosives, including licensing and permitting, business operations, record keeping and storage, is regulated by ATF in accordance with 27 CFR. However, a number of states and local authorities have particular regulations, especially concerning licenses, permits, and location of storage magazines. Anyone contemplating building or locating a storage magazine or purchasing explosive materials should make sure that they are in compliance with all applicable regulations.

The storage of explosive materials on mining property (underground and surface) is regulated by MSHA under 30 CFR while general industry and construction site storage (underground and surface) is regulated by OSHA under 29 CFR.

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For more detailed information on the storage of explosive materials, please consult the following publications:

IME Safety Library Publication Number 1, Construction Guide for Storage Magazines IME Safety Library Publication Number 2, The American Table of Distances IME Safety Library Publication Number 3, Suggested Code of Regulations for the Manufacture, Transportation,

Storage, Sale, Possession, and Use of Explosive Materials IME Safety Library Publication Number 14, Handbook for the Transportation and Distribution of Explosive

Materials

COMMERCIAL EXPLOSIVE MATERIALS

Commercial explosive materials include a wide variety of products used for mining, quarrying, construction, geophysical prospecting and agricultural blasting. Basically, explosive materials are products that undergo rapid decomposition, accompanied by the development of extremely high temperature and pressure.

Consult the following publications for detailed information on the handling of commercial explosive materials:

IME Safety Library Publication Number 3 Suggested Code of Regulations for the Manufacture, Transportation, Storage, Sale, Possession and Use of Explosive Materials

The National Fire Protection Association Publication Number 495, Manufacture, Transportation, Storage and Use of Explosive Materials

American National Standards Institute Publication A10.7, Safety Requirements for Transportation, Storage, Handling, and Use of Commercial Explosives and Blasting Agents – American National Standard for Construction and Demolition Operations

Common types of commercial explosive materials are as follows:

A. Dynamite

Dynamite, as invented by Alfred Nobel, consisted of nitroglycerin absorbed in an inert base, kieselguhr. This original dynamite was known as guhr dynamite. Subsequently, straight dynamite was developed by replacing the inert kieselguhr absorbent with active absorbents that entered into the explosive reaction and contributed to the energy of the dynamite.

Today there are five general types of dynamites;

1. Straight dynamite;

2. Ammonia or extra dynamite;

3. Gelatin dynamite;

4. Ammonia or extra gelatin dynamite; and

5. Semi-gelatin dynamite.

As previously noted, the straight dynamite consists of nitroglycerin absorbed in an active base. The strength of straight dynamite is expressed by the percentage of nitroglycerin that it contains. Thus, 50% straight dynamite contains 50% nitroglycerin.

In ammonia or extra dynamite, a portion of the nitroglycerin has been replaced by a sufficient amount of ammonium nitrate to maintain the grade strength. For example, 40% extra or ammonia dynamite is supposed to have the same strength as 40% straight dynamite but it does not contain 40% nitroglycerin.

Gelatin dynamite contains nitrocotton, which gelatinizes the nitroglycerin. This gelatinized nitroglycerin is then combined with the types of active dopes found in straight dynamite.

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Ammonia or extra gelatin dynamite is essentially gelatin dynamite in which a portion of the nitroglycerin has been replaced by ammonium nitrate.

Semi-gelatin dynamites are a modified form of ammonia gelatin dynamites, which have higher cartridge counts than the ammonia gelatins but better water resistance than the ammonia dynamites. Semi-gelatins are fairly cohesive and generally have good fume properties so they are well suited for underground blasting work.

In addition to these five grades of dynamites, low-density dynamites are produced by altering the formulations of the extra and extra gelatin dynamites to produce high cartridge counts.

Dynamites are produced in a wide range of strengths and detonation velocities. These two properties, along with the density of the explosive, are probably the most important characteristics in selecting dynamite for a particular application. Water resistance, fume properties, and sensitivity are also characteristics that must be evaluated when materials are to be used for wet work, in underground mining operations, or for propagation ditching.

Manufacturers normally supply dynamites in cartridges of 7/8 to 8 inches (22 to 203 millimeters [mm]) in diameter, but smaller or larger diameter cartridges may be manufactured for special purposes. Although the 8 inch (203 mm) length cartridges have long been the “standard” of the industry, cartridges are also manufactured in other lengths from 4 inches to 24 inches (100 mm to 610 mm). Cartridges of less than 6 inches (150 mm) in diameter are usually packaged in fiberboard cases having nominal net weights of 50 or 55 pounds (lb) (23 or 25 kilograms [kg]). Larger diameter cartridges (4 inch [100 mm] or larger) are usually shipped uncased. Individual large diameter cartridges can weigh from 10 to 60 pounds (4.5 kg to 27 kg) each (depending on diameter and length) and are shipped as single units or bundled to form units of 50 pounds (23 kg) or more.

B. Permissible Explosives

Permissible explosives are MSHA approved explosives, (dynamites, water gels or emulsions) which have been tested by MSHA and approved for use in mines where gasses and/or dusts produce explosive atmospheres. Permissible explosives are designed to produce a flame of low temperature, small size, and short duration. Permissible explosives, when used under blasting conditions that comply with MSHA's permissible blasting regulations, reduce the possibility of igniting explosive gases or dusts.

C. Demil Explosives

The term “DEMIL Explosive” is used throughout the commercial explosives industry to describe explosive products that contain certain types of military explosives as major ingredients or components. Usually, these military explosives can be divided into the simplified classes of high explosives, such as trinitrotoluene (TNT) and cyclonite (RDX), or propellants, such as smokeless powder (M-1, M-6, and M-30 gun propellants) and composite propellants, made up of ammonium perchlorate, aluminum and a binder (a rubber-like solid). One use for these composite propellants is in the solid booster motors used to launch the space shuttle. The explosive properties of these materials determine how they are used as energetic ingredients and sensitizers in commercial explosive products.

These energetic materials can come from a number of sources within the military or aerospace industries. They can result from the demilitarization and disposition of old or outdated military weapons systems, thus the term “DEMIL”, or as surplus energetic ingredients generated during the production of military weapons and rocket motors.

The use of “DEMIL” energetic materials as ingredients in commercial explosives is not a recent development. The commercial explosive industry has long used these materials as low cost sensitizers and energetic raw materials, whenever they have become available. This has usually coincided with the military scale-down at the end of a war (such as the recent end of the Cold War) or the development of more advanced weapons systems, (such as the development of the “smart-bomb” weapon systems). The advancement of environmental concerns and regulations has also led to a more determined effort to recycle “DEMIL” energetic materials as ingredients in commercial explosives.

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Some examples of the incorporation of military explosives as ingredients into commercial “DEMIL” explosives are the use of TNT, RDX, and Tritonal (TNT and aluminum) as ingredients in cast boosters. When in a suitable particle size, these molecular explosives are also used as energetic ingredients and sensitizers in packaged ANFO, water gel, slurry, and emulsion high explosives and blasting agents. Smokeless powder propellants that have been demiled from the propelling charges of small and large caliber guns have been used as sensitizers and energetic ingredients in packaged water gel slurry and emulsion blasting agents. Composite rocket propellants have also been properly sized and used as similar energetic raw materials. The use of these molecular explosives and propellants in commercial explosive products usually entails the implementation of increased safety precautions during the manufacturing and handling of these “DEMIL” explosives. However, as long as their use provides certain economic, environmental and performance advantages, “DEMIL” explosives will continue to hold a place in the commercial explosive market.

D. Emulsions, Slurries and Water Gels

Emulsions, slurries and water gels are explosive materials that contain fuels, oxidizers, water, sensitizers and gelling, crosslinking or emulsifying agents. While some are sensitized with high explosives, others contain aluminum or other metals, special fuels or oxidizers and/or microscopic air bubbles or micro-balloons.

Emulsions, slurries and water gels that pass the test criteria for Division 1.5 materials (blasting agents), as outlined in 49 CFR, can be shipped and stored as Division 1.5 materials (blasting agents). However, any product that does not meet DOT requirements for Division 1.5 materials (blasting agents) must be shipped and stored as Explosives 1.1 (Class A), even though none of its formulation ingredients are classified as high explosives.

Although emulsions, slurries and water gels may be premixed and packaged at an off-site mixing plant, some operations mix the materials at the blast site immediately before loading into the blasthole. Packaged materials range from conventional paper cartridges to flexible plastic tubes with metal clips or heat sealed closures at each end. Rigid plastic, self-coupling seismic cartridges; continuous length tubing; and plastic tubes with woven plastic or spiral wound fiberboard overwraps are available for special applications. In addition to on-site mixing, bulk- loading operations may also utilize pumping trucks that receive their materials premixed from storage tanks. For underground loading or the loading of small diameter holes, pressure pot type loaders or small pumping units are employed. These loaders are usually supplied by dumping bulk or large size packaged material into their holding tanks.

E. Division 1.5 Materials (Blasting Agents)

Division 1.5 materials (blasting agents) are explosive materials that meet prescribed criteria for insensitivity to initiation.

For storage, ATF regulations (Title 27 CFR, Section 55.11) define a blasting agent as any material or mixture, consisting of fuel and oxidizer, intended for blasting and not otherwise defined as an explosive; provided that the finished product, as mixed for use or shipment, cannot be detonated by means of a Number 8 Test Detonator when unconfined.

For transportation, DOT regulations (Title 49 CFR) define Division 1.5 materials (blasting agents) as very insensitive explosives. Classification tests show that these materials, though they have a mass explosion hazard, are so insensitive that there is very little probability of initiation or of transition from burning to detonation under normal transportation conditions. Division 1.5 materials (blasting agents) that contain no ingredients other than prilled ammonium nitrate and fuel oil are only required to pass a cap sensitivity test (Number 8 Test Detonator test).

As previously noted, a number of bulk and cartridged emulsions, slurries and water gels are classified as Division 1.5 materials (blasting agents). Perhaps the most common is the mixture of ammonium nitrate and fuel oil commonly referred to as ANFO. ANFO is available as a premixed, free running, bagged material that can be poured or blown into blastholes, or as a bulk product that is loaded directly into blastholes.

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Open pit operations employing bulk loading of ANFO may choose to obtain the prills and oil separately and do their own mixing, either at a fixed location or in portable equipment at the loading site.

At many locations, bulk ANFO is supplied by explosive manufacturers or distributors who either deliver the material to on-site storage bins for use by the operation's loading crew, or load the bulk ANFO directly into blastholes. ANFO blends consisting of bulk AN or ANFO, which is mixed with a water-based explosive or oxidizer matrix, is also supplied by explosive manufacturers or distributors who normally blend the materials at the blast site and load the blends directly into the blastholes. Ingredients to make ANFO blends (AN or ANFO and matrices) can be supplied in bulk by explosive manufacturers or distributors to locations that operate their own blending trucks. The use of ANFO blends enables the blaster to adjust the properties (density, water resistance, energy, etc.) of the product being loaded into the blasthole to accommodate specific conditions or requirements.

When used for underground operations ANFO is usually loaded by pneumatic equipment which blows the ANFO directly into the blasthole. Regulations prohibit the mixing of ammonium nitrate/fuel oil in underground locations. ANFO used underground is of the premixed variety and may contain special oils and/or additives to enhance its handling and fume characteristics.

ANFO type explosives (blasting agents) are characterized by low density and poor water resistance, making them ill-suited for wet hole blasting. However, they can be used for wet work, by crushing the ammonium nitrate, adding densifying agents to increase density, and packaging the finished product in a dimensional water resistant cartridge. Cartridged high-density (HD) ANFO products will perform satisfactorily if water conditions are not too severe, exposure time is not excessive, cartridges are loaded and remain intact, and the column of cartridges is adequately primed and boostered.

F. Boosters

Boosters are an explosive charge, usually of high detonation velocity and detonation pressure, designed to be used in the explosive initiation sequence between an initiator and the main charge. When a booster contains: (1) a detonator; or (2) detonating cord to which is attached a detonator designed to initiate the detonating cord, the unit becomes a primer. Explosive materials most commonly used as boosters include:

1. Cast, extruded, or pressed solid high explosive that is #8 detonator or detonating cord sensitive. May contain pentolite, TNT, composition B or similar type explosives and usually contain wells and/or tunnels to facilitate their use with electric, electronic, or nonelectric detonators or detonating cords.

2. Cartridges of high velocity, high density dynamites.

3. Packages of cap sensitive emulsions, slurries or water gels.

Both bulk blasting agents and cartridged blasting agents, due to their relative insensitivity, require high detonation pressure primers and boosters to assure maximum efficiency. Since the combination of high density and high detonation velocity produces the desired high detonation pressure, boosters, as a rule, are made of high velocity, high density explosives.

In recent years, new initiation and delay systems have been developed and special boosters are available for use with these systems. Components of all initiation and delay systems, especially detonating cords, are not compatible with all boosters. Booster, detonating cord, and initiating system manufacturers should be consulted regarding the use and application of their particular products.

G. Initiation Components and Systems

1. Cap and Fuse Systems Cap and fuse systems utilize a fuse detonator with safety fuse. Multi-hole blasting may also include the use of igniter cord.

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a. Fuse Detonators (Blasting Caps) Fuse detonators (blasting caps) are copper alloy or aluminum shells approximately 1/4 inch (6.4 mm) in diameter and about 1 inch (25 mm) to 1-1/2 inches (38 mm) long, which contain a charge of a dense, high strength explosive. One end of the shell is closed and the other end is open to allow the insertion of a safety fuse.

In use, safety fuse is inserted into the open end of the detonator with the end of the fuse resting on the explosive charge. Using a special tool (cap crimper), the detonator is crimped to the fuse to lock it in place.

The end spit of the burning safety fuse initiates the detonator, which will in turn initiate cap sensitive explosive materials such as dynamite, detonating cord, cast boosters, emulsions, slurries or water gels.

Fuse cap detonators will mass detonate and are very sensitive to flame, heat, friction and shock. They should never be carried in pockets of clothing, and must never be stored in the same magazine with other explosive materials other than detonators, electric squibs, safety fuse and igniter cord in a Type 1 or Type 2 magazine.

b. Safety Fuse Safety fuse is a flexible cord containing an internal burning medium by which fire or flame is conveyed at a continuous and uniform rate from the point of ignition to the point of use, usually a fuse detonator.

The safety fuse most commonly used in North America has a burning speed of approximately 40 seconds per foot. Since manufacturing tolerances, storage, weather, atmospheric pressure, mishandling and conditions of use affect the burning speed, it should be checked at frequent intervals on the job by timing a 3 foot (0.9 m) section from that part of the supply roll to be used.

A minimum of 3 feet (0.9 m) of safety fuse is recommended for use with each detonator.

c. Igniter Cord Igniter cord is a flexible, small diameter pyrotechnic cord that burns rapidly at a uniform rate with an external flame. Igniter cord is used to ignite a single fuse or a series of safety fuses.

Igniter cord connectors are small metal capsules containing an ignition compound. In use, a connector is crimped to the fuse; then the igniter cord is inserted under the “lip” of the connector and the lip is pressed closed with the thumb. As the igniter cord burns along its length, it ignites each connector that, in turn, starts each fuse burning.

In addition to lighting a single fuse, igniter cord and igniter cord connectors, when used with safety fuse, allow the ignition of multihole blasts in a delayed sequence without having to cut the safety fuse to different lengths. With this system the safety fuse is cut in equal lengths and the desired timing is accomplished through the burning speed of the igniter cord.

Detailed information on igniter cord systems can be obtained from an explosive materials supplier.

2. Detonating Cord Systems a. Detonating Cord Detonating cord is a flexible cord containing a center core of high explosives that is used to initiate other explosives. Detonating cord supplied for commercial blasting contain coreloads of 4.5 to 400 grains of explosive per foot. The coreload may be covered by textiles, waterproofing compounds, and plastics designed to protect the explosive core from damage by water or oil penetration. A detonator, such as an electric or electronic detonator, fuse cap, or other type of nonelectric blasting cap can initiate the detonating cord. Detonating cords with coreloads of 18 grains per foot or greater can be reliably initiated through knotted connections. For coreloads of less than 18 grains per foot, follow the manufacturer's recommendations.

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The detonation velocity of detonating cord is fairly consistent (approximately 22,000 feet [6700 m] per second) for all coreloads. However, the ability to initiate other explosives is a function of the weight per foot of explosive coreload, and users should consult the manufacturer to determine compatibility with cast boosters, nitroglycerin dynamite, emulsions, slurries, water gels and blasting agents.

Detonating cord allows the blaster to have a continuous initiating medium from the bottom to the top of the blasthole. This facilitates the introduction of boosters or primers anywhere in the explosive column and is especially desirable where the formation is badly fractured or backbreak is a serious problem and deck loading is necessary to implement proper distribution of the explosive charge.

When loading the hole, the detonating cord downline is securely attached to the first cartridge of dynamite or to the first cap sensitive booster to be placed in the hole. This unit is then lowered to the bottom of the hole and the detonating cord cut is from its spool. The spool is removed from the collar of the hole and the free end of the detonating cord downline is secured before loading commences. During loading, cap sensitive boosters of a diameter large enough to contact the detonating cord may be loaded into the blasthole, or cast boosters may be threaded on the detonating cord downline and allowed to slide down the column.

Detonating cord may be initiated and/or delayed by use of electric, electronic, or nonelectric in-the-hole or surface detonators. Detonating cord downlines may also be used to initiate in-the-hole cast boosters that contain delay detonators. Many combinations of systems may be devised using components from different manufacturers; it is imperative to check with the manufacturers to make sure that components are compatible.

Because detonating cord can cause high levels of airblast, which could lead to blasting complaints, surplus tails exceeding 8 inches (200 mm) should be cut from downlines and trunklines. When severe noise problems exist, it is recommended that surface lines of detonating cord be covered with 12 to 18 inches (300 to 460 mm) of sand or screenings to reduce noise.

Knotted connections for detonating cord lines should be tight and connected at right angles to the trunkline. When attaching detonators to detonating cord downlines or trunklines the “business end” of the detonator is pointed in the direction that the detonation is to travel.

CAUTION: Detonating cord downlines may adversely affect the performance of some explosive materials, especially

in small and medium diameter blastholes. Consult the explosives manufacturer for specific application recommendations.

b. Standard Detonating Cord System

Detonating cords is used for trunklines and downlines in multi-hole blasts and have coreloads between 7.5 and 50 grains per foot. There are many variations of systems employing combinations such as surface delay connectors and sliding primers. Heavier grain coreload detonating cords (up to 400 grains per foot) are used in specialized applications as both an initiator and main column charge, such as in presplit applications.

c. Miniaturized Field-Assembled Detonating Cord System The field-assembled miniaturized detonating cord system is comprised of a low coreload (about 2.4 to 6 grains per foot) detonating cord, instantaneous starters for connection with downlines and trunklines, millisecond surface delay connectors and in-hole delay detonators. The surface delays may be used with conventional detonating cord downlines or combined with in-hole detonators to produce a range of delay timings. The various components of the system are assembled at the blast site to accommodate the particular blast requirements.

d. Miniaturized Factory-Assembled Units Factory assembled miniaturized detonating cord units consists of a length of miniaturized detonating cord crimped to a nonelectric detonator. In application, the miniaturized detonating cord lead is attached to a detonating cord trunkline or other suitable means of initiation.

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Miniaturized detonating cord systems are not compatible with nitroglycerin sensitized explosives, since they will side-initiate these types of explosives. Miniaturized detonating cord systems, however, may be compatible with emulsions, slurries, water gels, and blasting agents. Questions regarding compatibility of detonating cord systems should be referred to the supplier or manufacturer of the system.

3. Shock Tube Initiation System The shock tube initiation system consists of a small diameter plastic tube that contains a thin coating of a reactive material on the inside surface. When initiated, this coating reacts and transmits a shock wave at approximately 6,000 to 7,000 feet (1800 to 2100 m) per second through the tube. For field use, factory- assembled units consisting of instantaneous or delay detonators, or other types of delay devices, crimped to lengths of shock tube are employed to provide in-the-hole or surface delays. These units can be used by themselves or in conjunction with other delay and initiation devices. Shock tube can be initiated by detonating cord, electric, electronic, or nonelectric detonators, cap and fuse or special starter equipment.

4. Electric Detonators (Electric Blasting Caps) a. Standard Electric Detonators

Standard electric detonators, instantaneous and delay, are closed aluminum, stainless steel or copper alloy shells approximately 1/4 to 1/3 inches in diameter (6.4 to 8.4 mm). Instantaneous electric detonators are 1 inch to 2 inches (25 to 50 mm) long while the delay electric detonators may be as long as 4 inches (100 mm). Two legwires, or other specialized conductors, are attached to one end of the detonators through a plug that has been crimped into the end of the detonator to provide a water resistant closure.

Inside an instantaneous detonator, the two legwires (or conductors) are connected to an ignition system that is positioned over the priming charge. The ignition system consists of a bridge element, connected across the legwire ends, and surrounded by a heat-sensitive pyrotechnic material. When electric current or pulse discharge is applied through the legwires, the bridge element heats up or vaporizes and ignites the surrounding pyrotechnic material, which, in turn, ignites the priming charge. The priming charge undergoes transition from deflagration to detonation and initiates a base charge. The detonation of the base charge initiates the detonator (cap)-sensitive explosives in which the detonator is embedded. In delay detonators, a delay element is positioned between the ignition system and the priming charge to introduce a predetermined delay between the application of firing current and the detonation of the base charge.

Delay electric detonators are available in long period and millisecond delay series. The long period delays have nominal delay intervals of one half to one second, while millisecond delays may range from 25 milliseconds (25 thousandths of a second) to 150 milliseconds (150 thousandths of a second) per delay interval. Electric detonators are sensitive to flame, heat, shock, and friction, and should not be handled roughly or carried in clothing pockets. They are also subject to accidental detonation by stray current or other sources of electrical energy and should be kept shunted at all times except when being tested or hooked into the blasting circuit.

b. High Energy Electric Detonators High-energy electric detonators (HEED) bear a close resemblance to standard electric detonators but operate in a fundamentally different manner; they contain no primary explosives. Two primary types of HEED exist, exploding bridgewire detonators (EBW) and exploding foil initiators (EFI). Both require electric current of over 150 amperes delivered in less than five microseconds. The associated high electrical power is generally obtained from a high-energy capacity discharge circuit. The resulting shock or pressure wave initiates a low-density secondary explosive in an EBW, or accelerates a flyer in an EFI.

5. Electronic Detonators There are numerous types of electronic detonator systems, each of which are differentiated from all other types of detonators because of their utilization of a stored electrical energy device (e.g. capacitor) to provide energy for their firing or timing and firing circuits. In addition to having an energy storage device for firing the igniter, electronic detonators also differ from other detonators by utilizing an Integrated Circuit (IC) or an Application Specific Integrated Circuit (ASIC) to provide millisecond precise timing as well as a level of communication and control over the firing circuit. Electronic detonators typically incorporate additional

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internal components designed to provide increased protection against accidental initiation from extraneous electrical energy (static, stray current, radio frequency, etc.).

The communication capability provided by the IC or ASIC found in electronic detonators provides a security feature not found with other standard detonator technologies. Wired types of electronic detonators can communicate specific information about the status of a detonator either prior to loading or post loading the unit into a blast hole. Communication features of these systems also offer the ability to “interrogate” the entire system prior to charging and firing a blast. Electronic detonator systems often use proprietary (coded) communication protocols, blast keys, and or logic circuits that can prevent the accidental initiation due to operator error or unauthorized use which provide a higher level of blast site security and misuse of the product.

Unlike an electric detonator, the igniter or firing device inside an electronic detonator is physically separated from the leads by a circuit board or electronic assembly. It is because of these design differences that traditional safety testing equipment such as a blaster’s galvanometer as well as shunting practices cannot be applied to electronic detonators. In fact, most electronic detonator systems and assemblies incorporate specific connectors, wiring techniques, or wire-harness designs that make it impractical or undesirable to make a “traditional” shunt in the detonator or blasting circuit.

Refer to Safety Library Publication 12 (SLP 12) for the definition of “shunting” and its applicability to both Electric and Electronic detonator systems.

As stated above, there are numerous types of electronic detonator systems. Each are unique in design and functionality. It is essential that users become fully educated on the products, procedures and recommended practices prior to use.

Their differences include detonator construction, timing precision, communication protocol, blasting machines, tie-in, connectors, etc. Although they are each uniquely different from one another, there are certain design features that are common to all.

Electronic detonator systems are grouped into two basic categories: Factory Programmed Systems (fixed delay) and Field Programmed Systems (variable delay). Factory Programmed Systems, in most cases, have a close resemblance to the conventional hardware and components found with standard electric detonators. In some cases, the user may even have a difficult time differentiating a wired electronic detonator from a wired electric detonator. Even though these units may not appear to be different, electronic detonators generally cannot be fired or shot using conventional blasting machines or firing devices. Each system can have a unique firing code or communication protocol used to fire the detonators in the blast.

Factory Programmed Systems can be further grouped into specific types or styles. There are Electrically Wired Systems, where each manufacturer has a specific wiring style or methodology; and Factory Programmed Systems that utilize shock tube technology to energize an electronic timing circuit within the detonator.

a. Factory Programmed Systems Factory Programmed Systems utilize “fixed” delay periods for the blast design. Holes are generally loaded and hooked up in the same manner as standard electric or shock tube systems. Depending on the manufacturer, some type of surface connector may be utilized for ease of wiring, or maintenance of correct electrical polarity. With some systems, correct polarity must be observed when electronic detonators are attached to the firing circuit, otherwise a misfire may occur. In all cases though, users of these systems should ALWAYS consult the manufacturer for specific application information and instructions.

b. Field Programmed Systems Field Programmed Systems utilize electronic technology to program delay times at the blast site. Each system is manufactured for, or with, unique system architectures, styles, hardware, and communication protocol. There are no fixed delay times associated with these detonators. These systems rely on direct

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communication with the detonator (either prior to loading, after loading, or just prior to firing) for the proper delay time and subsequent blast design. In general, these systems will utilize some type of electronic memory, which allows them to be reprogrammed at any time up until the fire command is given.

As with a Factory Programmed System, it is very important that users always consult the manufacturer for the specific instructions on the operation of any Field Programmed System. Each system is unique. Blasting machines, equipment, and detonators from one system should never be mixed with other systems. By design, a system from one manufacturer will not work with one from another; such attempts would only result in a misfire.

For ease of identification, all detonators manufactured in North America (except HEEDs) have the safety warning, “EXPLOSIVE - EXPLOSIF - DANGER - DÉTONATEUR - BLASTING CAP” printed on the shell.

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BLASTING MACHINES, TESTING MACHINES, AND ACCESSORIES

The proper supplies, quality accessories, and equipment maintained in a state of good repair, are essential to any blasting operation. Equipment should be checked and tested periodically and any worn, broken or malfunctioning items repaired or replaced promptly. When conducting blasting operations or otherwise handling explosive materials, the quality or serviceability of equipment and supplies cannot be compromised.

A. Blasting Machines for Electric Detonators

Blasting machines are devices used to initiate blasts. There are several different types depending on the application.

1. Generator-Type Blasting Machines Generator-type blasting machines are direct current generators manually operated by pushing down a rack bar or twisting a handle. Peak energy is delivered at the end of the generating action. Generator-type machines have no energy storage capacity or any built-in means of indicating their operating condition or output. Both the push down and twist type generators have been in use for many years and are rugged, reliable blasting machines. Following the manufacturer's rating on the blasting machine and operating the machine vigorously when firing a blast will assure optimum performance. Machines should be tested periodically to ensure they are delivering rated the output.

2. Capacitor Discharge Blasting Machines Capacitor discharge (CD) blasting machines contain one or more energy storage capacitors that are charged by batteries or a manually-operated generator. Most CD blasting machines have a meter or lamp that indicates when the capacitors are fully charged, and a firing switch to discharge the electrical energy from the capacitors into the electric blasting circuit. Some machines, however, automatically discharge the capacitors when a preset voltage has been reached. The ability of CD blasting machines to store electric charge on the capacitors, and then discharge this charge rapidly into the blasting circuit, makes them extremely efficient in terms of the number of detonators that can be fired in a blast. CD machines are characterized by small size and high firing capacity. Some weigh only a few ounces and are rated to fire 10 or more detonators. Larger machines are available that are rated to fire 1,000 or more detonators. Since there are few moving parts in CD blasting machines, the most important considerations for keeping them in good operating condition are to safeguard the shelf life of the capacitors by not exposing them to temperature extremes and to replace the batteries as necessary.

CAUTION: When using a blasting machine that is a combination firing unit and circuit tester for any type of initiation system, the blast area must first be cleared of all personnel before testing the circuit.

3. Sequential Blasting Machines Sequential Blasting Machines are specially designed machines that discharge individual capacitors at predetermined time intervals in order to produce a delay sequence. Sequential blasting machines are available for a number of applications, and can be furnished with special cables, terminal boards, and testing equipment.

4. Permissible Blasting Machines Permissible blasting machines are either generator or capacitor discharge type machines that have been approved by MSHA for use in underground coal mines. Permissible blasting machines must bear the MSHA seal of approval.

CAUTION: All electric blasting machines can deliver high voltage and current. Care should be taken when connecting

the blasting lead line to the terminals to make sure that bare leads do not touch each other, cannot be grounded against the blasting machine case, and cannot be accidentally touched by the operator firing the blast.

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B. Shock Tube Starters

Shock tube is initiated with devices called shock tube starters, which typically use shot shell primers or small electric sparks to initiate the shock tube. The shock tube lead line should not be inserted into the device until the blast area is cleared and guarded, and the final warning signal has been given.

CAUTION: Do not use any device or method that is not specifically designed for or recommended by the shock tube manufacturer.

C. Testing Equipment for Electric Detonators

CAUTION: Use only those meters specifically designed for testing electric detonators and blasting circuits. Some meters look

like blasting test meters, but they utilize test currents that may be capable of firing an electric detonator.

Blasting galvanometers and blasting ohmmeters are electrical resistance measuring devices designed specifically for the testing of electric detonators and electric blasting circuits. Either a silver chloride cell or a dry cell with special current limiting circuitry may power these devices, keeping the test current below specified limits.

Blaster's multimeters are versatile, multipurpose test instruments designed to measure resistance and voltage in electric blasting operations. They can also be employed for measuring stray current.

Ground current monitors are designed to monitor extraneous DC and AC currents. Lightning detectors, or atmospheric electrostatic field monitors, are used to monitor electrical phenomena associated with thunderstorms. They can warn of the approach of a thunderstorm and give indication of its closeness and severity.

Blasting machine testers can be the rheostat-type unit used for testing generator-type blasting machines, or special testers to measure the output energy from CD or sequential blasting machines.

D. Electronic Detonator Blasting Accessories

Historically, blasting machines are generic to the industry and can be used with, or for, most any standard electric detonator. One should NEVER attempt to use electronic detonators with a conventional electric blasting machine.

Due to varying design and specification of electronic detonator systems (e.g., field programmed vs. factory programmed, communication protocols, connector style, etc.) there may be multiple components and accessories that are required for proper operation of each system. These may include a blasting machine, programming unit, logging unit, testers, special connectors, memory modules, computer interface, and other peripherals.

NEVER attempt to use blasting machines, testers, or instruments with electronic detonators that are not specifically designed for the system.

NEVER test or program an electronic detonator in a booster, cartridge or other explosive component (Primer Assembly) before it has been deployed in the borehole or otherwise loaded for final use.

ALWAYS check wired electronic detonators for proper hook-up and/or programming with the testing and logging equipment specified by the manufacturer before the holes are stemmed unless otherwise directed by the manufacturer.

NEVER use test equipment designed for electric detonators with electronic detonators.

Whenever possible, individual programmed delay times should be verified against the blast plan prior to arming the system or final hook-up.

Shock tube electronic detonators may be handled in the same manner as other shock tube devices.

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E. Other Accessories

A blaster needs proper tools and accessories to perform efficiently and safely. In addition to proper personal protective equipment (PPE), a good powder knife, a measuring tape with lead weight, loading poles, lowering rope and hooks, mirror, powder punch, wire strippers and cap crimpers are examples of basic, essential tools for routine daily blasting work. Some blasting may require special tools or equipment such as blasting mats, tamping bags, fall prevention or fall arrest restraints, water, or air supplies.

Additionally, specialized electronic equipment, such as laser profilers, borehole deviation measurement devices, global positioning systems (GPS), and video recorders are being used to enhance the safety and productivity of blasting operations, as well as improving record keeping.

The blaster should not start or attempt a blasting job unless he or she is properly equipped.

FIELD USE OF INITIATION SYSTEMS

A preblast sketch should be made of the blasthole pattern, showing the proposed delay pattern and the detonator layout. Based on this sketch and the measured depth of holes, the blaster will know how many and what length of detonators are required for the blast. Frequently, for assurance, blastholes are “double primed”; a second primer is placed in the hole, usually near the top of the powder column, to serve as a back-up initiator in case the first primer fails to function or there is a cutoff due to rock movement. This back-up primer may be of the same or a later delay interval than the primary detonator.

Detonators and cast boosters, or other priming medium used as boosters, can be laid out at the collar of the hole in accordance with the delay layout so that the primers can be made up as the holes are loaded. Detonators should be securely contained within the booster so that they will be adequately protected and maintain intimate contact with the booster.

ALWAYS discontinue operations at the approach of an electrical storm.

A. Electric Detonators

Electric detonators should be checked for continuity with a blasting galvanometer, blasting ohmmeter, blaster's ohmmeter or blaster's multimeter before the holes are stemmed. After testing, detonator leg wires are reshunted until wired into the blasting circuit. Consult IME SLP-20, “Safety Guide for the Prevention of Radio Frequency Radiation Hazards in the use of Commercial Electric Detonators (Blasting Caps)” for guidelines on the safe use of standard electric detonators near radio frequency sources.

B. Electronic Detonators

Field use of any electronic detonator system must begin with the user becoming fully trained on the specific system intended for use. Individual manufacturers will provide the necessary training materials, instructions, and or, equipment for proper use of their systems. Users that do not obtain adequate training from the manufacturer should not attempt to use any electronic detonator system. Most manufacturers of these systems will typically require “competency based” training and assessment programs prior to use of their product.

C. Nonelectric Detonators

Many blasting projects utilize nonelectric delay systems to achieve the surface or in-the-hole delay sequence of their blasting pattern. These systems can consist of millisecond delay surface connectors, shock tube, miniaturized detonating cord, down-the-hole delay primers, or a combination of these systems. When utilizing these systems, insure that shock tube to detonating cord connections are at right angles to prevent angle cut-offs. Avoid situations where initiation system components can become entangled in machines, equipment, vehicles or moving parts thereof, because pulling, stretching, kinking or putting tension on a shock tube could cause it to break or otherwise malfunction. Protect surface delay connectors from unintended energy sources, such as: impact from falling rock, impact from track vehicles or other mobile equipment, drilling equipment, flame, friction, electrical

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discharge from power lines, static electricity and lightning. Follow the manufacturers' recommendations when cutting and splicing lead-in trunkline shock tube. An initiation signal will not pass through a knotted connection if two lengths of shock tube are tied together. Do not hook-up a surface delay connector to its own shock tube or remove the detonator from a surface delay connector block. Leaving an un-hooked surface delay connector in close proximity to the shock tube of a loaded blasthole or attempting to initiate detonating cord with a surface delay connector designed for the initiation of shock tube only may result in a misfire. If a misfire occurs, always unhook surface delay connectors before handling the misfire. Because these systems can consist of millisecond delay surface connectors, shock tube, miniaturized detonating cord, down-the-hole delay primers, or a combination of these systems, the systems are sometimes not compatible with each other or with certain types of blasting materials. The user should consult the manufacturer or supplier for details regarding the properties and applications of a particular nonelectric delay system.

GROUND VIBRATION AND AIRBLAST

A. Ground Vibration

In all commercial blasting operations, a portion of the energy released upon detonation of the explosives is manifested as ground vibration and airblast. Except in geophysical prospecting, ground vibration is an undesirable by-product of blasting. Although ground vibration cannot be eliminated from blasting operations, it can be controlled or minimized by employing good blast design.

Generally, blast patterns designed with excessive burdens and spacings can be expected to produce rather high ground vibration while the accompanying airblast may be rather low. On the other hand, blast patterns with extremely light burdens and spacings may produce rather high airblast with comparatively low ground vibration. Blast patterns should be designed to produce optimum results—minimum ground vibration and minimum air blast.

When an explosive material detonates in a borehole, the near-instantaneous generation of a shock wave and high pressure produces an intense stress wave in the surrounding rock. Practically all the energy in the explosion is expended in shattering and displacing the rock around it. The energy left over will be dissipated through the ground in the form of elastic waves that radiate away from the blast site. The explosion will have a three-zone effect near the borehole. Immediately adjacent to the borehole, the explosive action pulverizes the material. As the stress wave propagates outward from the hole, it rapidly decreases in intensity and the crushing action is reduced to a fragmenting stage. Finally, the strength of the stress wave is so attenuated that no breakage occurs, and the remaining vibratory energy is propagated outward as a seismic wave. This wave has no permanent displacement effect, and all vibrating rock particles eventually return to their original position. This latter zone, known as the “elastic zone”, might contain homes and other structures where occupants, fearful of personal injury and/or structural damage, may complain about the vibrations.

Blasting vibrations can be reduced by a good blast design that provides an optimum powder factor and maximum practical relief. In addition, shorter holes in lower benches, deck loading and the use of delay initiators with sequential blasting machines, electronic initiating systems, or nonelectric delays and surface delay connectors to reduce the charge-weight-per-delay will help to decrease undesirable vibration.

Blasting vibrations can be detected and recorded by seismographs, and are usually measured in one of three modes: particle displacement, particle velocity or particle acceleration. These are measured as a function of time and are recorded in three mutually perpendicular directions. Particle velocity measurement is most widely used when monitoring commercial blasting operations.

Based on a study of blasting vibration, published by the United States Bureau of Mines (USBM) in Bulletin 656, the following equation was developed to determine maximum peak particle velocity:

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s

V = k ( D )−m

Where:

max

W 1 / 2

Vmax = peak particle velocity (in/sec) D = distance between the explosion and receiving sites (ft) W = maximum weight of explosives that can be detonated within any

period less than 8 milliseconds (lbs) k and –m

= Site factors based on the geology and ground transmission characteristics of the rock at the blast site as determined by seismographic measurements.

V = 160( D )−1.6 max W 1 / 2

Based on a large number of field measurements made at actual blasting operations it has been determined that the following propagation equation can be used to conservatively estimate peak particle velocity for blast planning purposes.

Where:

Vmax = peak particle velocity (in/sec) D = distance between explosion and recording site (ft) W = maximum weight of explosives that can be detonated

within any period less than 8 milliseconds (lbs)

NOTE: For particular sites the equation may have to be modified as site-specific seismic data becomes available.

To set limits for ground vibration from blasting, some regulatory agencies, federal, state, or local, require that blasting operations conform to a specified scaled distance (Ds). For ground vibrations, scaled distance (Ds) is defined as the ratio of the distance “D” from the blast to a location of concern, divided by the square root of the explosive weight “W” detonated in any delay interval of 8 milliseconds or greater.

The formula for scaled distance is expressed as:

Ds = D W 1 / 2

Thus: Ds (ft / lb1/ 2 ) =

D( ft )

W 1/ 2 (lb)

D (m/ kg1/2 )= D(m)

W 1/2(kg)

Usually blasting vibration regulations also specify that the maximum peak particle velocity generated in any of three mutually perpendicular directions, vertical, horizontal, or transverse, may not exceed a certain limit. The USBM study in Bulletin 656 concluded that 2.0 in/sec (50.8 mm/sec) was a safe blasting limit.

In recent studies (USBM Report of Investigations 8507) the bureau found that particle velocity is still the best single ground motion descriptor. The bureau also investigated the roles of blast frequency and building construction as factors in damage potential from blasting vibrations. The bureau's latest conclusions on safe levels of blasting vibration for residences are shown in Figure 1 below.

22

Figure 11 Alternative Blasting Criteria

For surface coal mine blasting operations, vibration and airblast are regulated by the Office of Surface Mining (OSM) in 30 CFR, Parts 816 and 817. Under the OSM regulations, an operator may elect to use one of the following options to control blasting vibration:

1. Maximum allowable peak particle velocity from column 1 of Table I

or

2. Scaled distance factor from column 2 of Table I .

or

Table 26.182 - Scaled Distance

1 Figure B-1 from USBM Report of Investigations 8507 2 Table 26.18 from ISEE ‘ Blaster’s Handbook 18th Edition’

Blast Vibration Frequency, Hz

100 15 10 2.65 1 0.1

1 0.75

10

Drywall Plaster

Par

ticle

Vel

ocity

, in/s

ec

23

3. The blasting level chart, Figure 2 (a modification of USBM chart from RI 8507).

Figure 22 Alternative Blasting Level Criteria

B. Airblast

Many airblast complaints to blasting operations are based upon the annoyance that airblast can cause, rather than upon actual structural damage. The startling effect of noise and the rattling of windows cause people to naturally assume that their residence has been shaken so violently that structural damage has occurred. Actually, the airblast from normal blasting operations is rather unlikely to cause structural damage. Airblast limits specified by OSM regulations in 30 CFR for surface coal mining (noted below in Table II) represent acceptable safe limits, which are generally accepted by state and local regulatory agencies for commercial blasting operations.

TABLE II

Lower Frequency Limit of Measuring System, in Hz (±3dB)

Maximum Level in decibels (dB)

0.1 Hz or lower-flat response* 2 Hz or lower-flat response 6 Hz or lower-flat response

C-weighted—slow response*

134 peak 133 peak 129 peak

105 peak dBC

* Only when approved by the regulatory agency. Hz = Hertz = Cycles per second dB = Decibels

Airblast can be affected by many factors including blast site orientation, stemming, initiation system, blast pattern and atmospheric conditions such as temperature, wind direction, fog, haze, and temperature inversion. All of these factors must be evaluated if airblast poses a problem at blasting operations.

C. Conclusion

In recent years, there has been a marked increase in litigation involving claims for damages reportedly caused by ground vibration and/or airblast from blasting operations. One of the best defenses against such claims is, of course, a combination of complete and accurate blasting logs and seismographic records. Anyone involved in

2 Modified from Figure B-1 from USBM Report of Investigations 8507

100 11

10 Blast Vibration Frequency, Hz

1 0.1

1 0.75

10

Max

imum

Allo

wab

le P

artic

le V

eloc

ity,

in/s

ec

24

blasting where damage claims for vibration and/or airblast are likely should make sure that detailed blasting logs are kept of all blasts, and that permanent seismic recordings are retained. The accuracy of records can be advanced by the use of laser profilers, borehole deviation devices, and GPS to document burdens, hole placement and the location of nearby structures.

Before starting any blasting work, a program to establish good public relations with the residences and businesses located near the blasting operations should be instituted; this may include a preblast survey. Experience has shown that such a program can be of great help in reducing blasting vibration and airblast complaints. The public relations program should be designed to explain the blasting operation, the need for the blasting, the precautions (scaled distances, weight limitations, stemming, matting, etc.) that are employed to mitigate the effects of blasting, and the monitoring equipment and methods that will be employed to assure that blasting effects are kept within safe and legal limits.

When possible, blasts should be scheduled during busy hours of the day when they will be less noticeable and less disturbing. A blasting time schedule should be developed and a system to provide adequate notification and warning to neighbors should be implemented. Any complaints involving adverse effects from the blasting operations should be recorded and investiga