SafetyPrecautioninBlastingOperation.doc

Safety Precaution in Blasting Operation.1. Blasting and Explosives Awarenessa. Introduction Explosives and blasting operations are widely used on construction projects to move underlying rock. While the explosives are becoming more reliable and efficient, undetonated or partially detonated charges can pose significant hazards should they be undetected or handled incorrectly.This document is divided into two sections outlining how workers may come into contact with explosives and methods to eliminate or minimize hazard exposure. The first section addresses work sites in which qualified drilling and blasting subcontractors are employed while the second section concerns work sites at which blasting activities are not part of the contract, although the sites included blasting activities in the past.b. Construction Activities AffectedEmployees of blasting subcontractors are continually exposed to the hazards associated with the use of explosives. These workers and their companies are required under federal and provincial legislation to have specific procedures and practices addressing the safe transportation and handling of explosives and associated equipment.Excavation crews working on sites involving blasting operations may be exposed to the hazards of undetonated charges during removal of blasted rock. Such excavation may be required for road building, pipeline work, housing, commercial or industrial construction, power plants, bridge construction, and the like.Construction crews working on sites where blasting is not required, but occurred in the past, may also be exposed to the hazards of partially or undetonated explosives still active underground.c. Responsibility of Blasting SubcontractorThe blasting subcontractor shall comply with all federal and provincial legal requirements in connection with the use, storage, and transportation of explosives.Only workers thoroughly experienced in handling explosives shall be permitted to supervise, handle, haul, or detonate explosives. The blasting subcontractor shall follow all pertinent construction regulations in addition to its own written precautions and procedures in protecting workers from the blasting site during drilling, charging, detonation, and inspection.An audible blast warning system must be employed to warn workers on the site of the impending blast, as well as clearance to re-enter the blast zone (all clear signal). Once the blast has occurred, and prior to giving the all-clear signal, the blasting subcontractor is responsible for conducting an inspection of the blasted area to ensure that all charges have detonated. If charges are found to be partially detonated or undetonated altogether, the blasting subcontractor shall ensure that the explosive charges are dealt with in a safe manner. d. Record of Blasting InformationEach blasting subcontractor shall keep an accurate record of type and amount of explosive used, blast pattern, depth of drill holes, and location of suspected misfires (not found) for each project worked on. This record shall be retained by the blasting subcontractor and the owner of the project to ensure that future subcontractors can refer back to it as required. If blast holes or patterns were laid out by survey methods, those records shall also be retained to ensure accuracy of locating blast holes and blasting limits in future works.e. Responsibility of Other Subcontractors on SiteEmployers on a site with drilling and blasting activities are responsible to ensure worker safety. All employers must be aware of hazards from lost, partially detonated, or undetonated explosives along the right-of-way where blasting has taken place. These explosives may be located in drill holes, rock rubble, or lodged in bootlegs.The subcontractor in charge of excavating blasted material shall equip all excavating machinery used in the clearing and grading operation with shatterproof glass (Lexan Mar Guard or equivalent) in front of the operators position. This initiative will protect the operator from fly-rock should the equipment encounter undetonated charges. Personnel attending backhoes or loaders involved in excavating blasted material must stay clear of the work and only approach the area when the equipment has stopped. All employers shall ensure that workers and operators wear the prescribed personal protective equipment for the task assigned.Employers must instruct and ensure that all workers immediately report to their supervisor any suspected misfires or explosives found during excavation or other work.f. Precautions When Working in Blasted AreasThe blasting subcontractor must be cautious when preparing for another round of drilling and blasting on the same site. The blasting subcontractor must be able to identify all previous blast holes to ensure that new holes are not drilled on top of them, potentially setting off partially detonated charges still present at the bottom of the hole.2. BLASTING AND USE OF EXPLOSIVES. 01. Scope a. Blasting and use of explosives shall conform to all other applicable requirements of this standard, as well as the following provisions. Nothing in this standard shall be construed to prohibit better or otherwise safer conditions than specified herein. 02. Definitions: a. Approved Storage Facility is a facility for the storage of explosive materials conforming to the requirements of this section. b. Blast Area is the area in which explosive loading and blasting operations are being conducted. c. Blasting Agent is any material or mixture consisting of a fuel and oxidizer used for blasting, but not classified as an explosive and in which none of the ingredients is classified as an explosive provided the furnished (mixed) product cannot be detonated with a number eight (8) test blasting cap when confined. d. Blasting Cap is a metallic tube closed at one end, containing a charge of one or more detonating compounds. e. Block Holing is the breaking of boulders by firing a charge of explosives that has been loaded in a drill hole. f. Bus Wire is an expendable wire, used in parallel or series, in parallel circuits, to which are connected the leg wires of electric blasting caps. g. Connecting Wire is an insulated expendable wire used between electric blasting caps and the leading wires or between the bus wire and the leading wires. h. Conveyance is any unit for transporting explosives or blasting agents, including but not limited to trucks, trailers, rail cars, barges, and vessels. i. Detonating Cord is a flexible cord containing a center core of high explosive which when detonated, will have sufficient strength to detonate another cap. j. Detonator is any of the following: blasting caps, electric blasting caps, delay electric blasting caps, non-electric blasting caps, and non-electric delay blasting caps. k. Electric Blasting Cap is a blasting designed for and capable of detonating by means of an electric current. l. Electric Delay Blasting Caps are caps designed to detonate at a predetermined period of time after energy is applied to the ignition system. m. Explosives are any chemical compound, mixture, or device, the primary or common purpose of which is to function by explosion; that is, with substantially instantaneous release of gas and heat. n. Fuse Lighters are special devices for the purpose of igniting safety fuse. o. Leading Wire is an insulated wire used between the electric power source and the electric blasting cap circuit. p. Magazine is any building or structure, other than an explosives manufacturing building, used for the storage of explosives. q. Misfire is an explosive charge which failed to detonate. r. Mud Capping is the blasting of boulders by placing a quantity of explosives against a rock, bolder, or other object without confining the explosive in a drill hole. (Sometimes known as bulldozing, adobe blasting)s . Non-Electric Blasting Cap is a blasting cap designed for and capable of detonation from the sparks or flame from a safety fuse inserted and crimped into the open end. t. Non-Electric Delay Blasting Cap is a blasting cap with an integral delay element in conjunction with and capable of being detonated by a detonation impulse or signal from detonating cord. u. Permanent Blasting Wire is a permanently mounted insulated wire used between the electric power source and the electric blasting cap circuit. v. Primary Blasting is a blasting operation by which the original rock formation is dislodged from its natural location.w. Primer is a cartridge or container of explosives into which a detonator or detonating cord is inserted or attached. x. Safety Fuse is a flexible cord containing an internal burning medium by which fire is conveyed at a continuous and uniform rate for the purpose of firing blasting caps. y. Secondary Blasting is the reduction of oversize material by the use of explosives to the dimension required for handling, including mud-capping and block-holing. z. Stemming is a suitable inert incombustible material or device used to confine or separate explosive in a drill hole, or to cover explosives in mud-capping.aa. Springing is the creation of a pocket in the bottom of a drill hole by use of a moderate quantity of explosives in order that larger quantities or explosives may be inserted therein. bb. Water Gels or slurry Explosives are a wide variety of materials used for blasting. They all contain substantial preparations of water and high preparations of ammonium nitrate. 03. General Requirements: a. The employer shall permit only authorized and qualified persons to handle and use explosives. b. Smoking, firearms, matches, open flame lamps, and other fires, flame or heat producing devices and sparks shall be prohibited in or near explosive magazines or while explosives are being handled, transported, or used. EXCEPTION: Law enforcement officials and persons carrying firearms for the protection of the explosives or explosive operation. c. No person shall be allowed to handle or use explosive while under the influence of intoxicating liquors, narcotics, or other dangerous drugs. d. All explosives shall be accounted for at all times. Explosives not being used shall be kept in a locked magazine, unavailable to persons not authorized to handle them. The employer shall maintain an inventory and use record of all explosives. Appropriate authorities shall be notified of any loss, theft, or unauthorized entry into a magazine. e. No explosives or blasting agents shall be abandoned. f. No fire shall be fought where the fire is in imminent danger of contact with explosives. All explosives shall be removed to a safe area and the fire area guarded against intruders. g. Original containers or Class II magazines, shall be used for taking detonators and other explosives from storage magazines to the blasting area. h. When blasting is done in congested areas or in proximity to a structure, railway, highway, or any other installation that may be damaged, the blasted shall take special precautions in the loading, delaying, initiation, and confinement of each blast with mats or other methods so as to control the throw of fragments, and thus prevent bodily injury to employees. i. Employees authorized to prepare explosive charges or conduct-blasting operations shall use every reasonable precaution including, but not limited to, visual and audible warning signals, flags, or barricades, to ensure employee safety. j. Blasting operations shall be conducted between sunup and sundown. k. Due precautions shall be taken to prevent accidental discharge of electric blasting caps from current induced by radar, radio transmitters, lightning, adjacent power lines, dust storms, or other sources of extraneous electricity. l. Electric detonators shall be short-circuited/shunted until wired into the blasting circuit. The blasting wire shall be short-circuited/shunted until ready to be fired. m. The suspension of all blasting operations and removal of persons from the blasting area when an electric storm is within three (3) miles and during the progress of an electric storm. n. Adequate signs shall be prominently displayed warning against the use of mobile radio transmitters, on all roads within one-thousand (1,000) feet of blasting operations. Whenever adherence to the one-thousand (1,000) foot distance would create an operational handicap, a competent person shall be consulted to evaluate the particular situation, and alternative provisions may be made which are adequately designed to prevent any premature firing of electric blasting caps. A description of any such alternatives shall be reduced to writing and shall be certified as meeting the purposes of this section by the competent person consulted. The description shall be kept at the job site during the duration of the blasting operations and shall be available to representatives of the Department upon request. o. Mobile radio transmitters which are less than one-hundred (100) feet away from electric blasting caps, in other than original containers, shall be de-energized and effectively locked. p. Empty boxes, paper, and fiber packing materials, which have previously contained high explosives, shall not be used again for any purpose, but shall be destroyed by burning at an approved location. q. Explosives, blasting agents, and blasting supplies that are obviously deteriorated or damaged shall not be used. r. delivery and issue of explosives shall only be made by and to authorized persons and into authorized magazines or approved temporary storage or handling areas. s. Blasting operations in the proximity of overhead power lines, communication lines, utility services, or other services and structures shall not be carried on until the operators and/or owners have been notified and measures for safe control have been taken. t. The use of black powder shall be prohibited.u. All loading and firing of explosives shall be directed and supervised by competent persons throughly experienced in this field. v. All blasts shall be fired electrically with an electric blasting machine or properly designed electric power source, except