Does "Subpart U - Blasting and the Use of Explosives" Apply to You?

Subpart U applies to blasting and using explosives. Are your employees engaged in blasting or the use of explosives? If yes, then this subpart applies to you. The definitions applicable to the subpart provide key definitions such as:

Blasting agent  -  Any material or mixture consisting of a fuel and oxidizer used for blasting, but not classified an explosive and in which none of the ingredients is classified as an explosive provided the furnished (mixed) product cannot be detonated with a No. 8 test blasting cap when confined. A common blasting agent presently in use is a mixture of ammonium nitrate (NH(4)NO(3)) and carbonaceous combustibles, such as fuel oil or coal, and may either be procured, premixed and packaged from explosives companies or mixed in the field.

Explosives  -  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, unless such compound, mixture or device is otherwise specifically classified by the U.S. Department of Transportation and all material which is classified as Class A, Class B, and Class C Explosives by the U.S. Department of Transportation.

The general provisions standard provides requirements pertaining to authorized and qualified persons, heat sources, inventory and use record, use of drugs and alcohol, special precautions, signage, radio transmissions, deteriorated explosives, delivery, black powder, and storage buildings (i.e., building construction, flooring, ventilation, mixing water gels, heating units).

The blaster qualifications standard provides the requirements for the blaster to be qualified, in good physical condition, capable of receiving and giving orders, not addicted to drugs and alcohol, knowledgeable of state and local regulations pertaining to explosives, evidence of competency, and knowledgeable in each type of blasting methods used. 

The surface transportation of explosives standard provides requirements pertaining to meeting the provisions of the Department of Transpiration requirements, driver criteria (i.e., physical condition, licensed, trained on fire extinguishers, familiar with local, state and federal regulations), ignition sources, vehicle maintained in good condition, placarding, not left unattended and other safety measures.

The standard on storage of explosives and blasting agents provides requirements for storing explosives in approved facilities (under applicable provisions of the bureau of Alcohol, Tobacco, Firearms and Explosives), storing caps, primers and cartridges separately from explosives and blasting agents, exits, and underground storage.  

The loading of explosives or blasting agents standard provides requirements for having safe and efficient loading procedures, not allowing unattended explosives and blasting agents, and no activity allowed in blast area working in areas with combustible gas and dusts. It also provides requirements pertaining to drill holes, tamping, loading holes, drilling, machines and tools, powerlines and electric cables, ventilation, warning signs, bore holes, running inventory of explosives and blasting agents, and bonding and grounding. 

The standard on initiation of explosive charges-electric blasting provides requirements for not using electric blasting caps near sources of extraneous electricity, eliminating dangerous currents, blaster surveying for extraneous currents, using same style or function of blasting caps, and following electric blasting cap manufacturer's recommendations.  It provides requirements related to insulated connecting wires and lead wires, bus wires, insulation on firing lines, not grounding power circuit used for firing electric blasting caps, underground operations (i.e., safety switches, lightning gaps), firing switches, use of blasting machines, use of blasting galvanometers and other instruments, and working around live powerlines.  

The use of safety fuse standard provides requirements pertaining to using a safety fuse where sources of extraneous electricity make the use of electric blasting caps dangerous, not using hammered or injured fuses, not hanging fuses on nails or other projections, having fresh cut ends, and use of cap crimpers.  It also provides requirements pertaining to unused caps, sources of ignition, not carrying detonators or primers, minimum length of a safety fuse, hand lighting methods, length and burning rate of fuses, firing mudcap charges, and not using "drop fuse" method of dropping or pushing a primer or any explosive with a lighted fuse attached.

The use of detonating cord provides the requirements for using care in the selection of the detonating cord, handling detonating cord with same respect given explosives, cutting from the supply spool, and to avoid damaging the detonating cord. It provides requirements for competent and positive detonating cord connections, inspecting detonating cord connections, trunklines and branchlines free of loops and kinks, following manufacturer recommendations, securely attaching blasting caps, and when to bring in or attach the detonators. 

The standard on firing the blast provides the requirements for posting the code of blasting signals, use of a loud warning signal by blaster in charge before firing a blast, having flagman stationed on highways, fixing time of blast, and for underground blasts, guarding entrances and providing a warning before the blast.    

The inspection after the blasting standard provides the requirements for disconnecting the firing line from the blasting machine immediately after the blast has been fired, inspecting the blast area and rubble by the blaster to determine if all charges have exploded before allowing employees in the area, and for blasts in tunnels, allowing time for smoke and fumes to leave blast area and for the muck pile to be wetted down before allowing employees in the area.

The standard on misfires provides the requirements for safeguarding the danger zone when a misfire is found, removing the misfire, handling cap and fuse misfires, reblasting holes (i.e., if reblast a hazard, removing explosives with water; under water misfires blown out with air), and not allowing work (i.e., drilling, digging, picking) until all missed holes have been detonated or until work has been approved by authorized representative.  

Do you transport explosives underground? Do you conduct underwater blasting? Do you conduct blasting in excavation work under compressed air? If you said yes to any of these questions, you will also need to comply with those standards that are specific to that type of operation. Click on the appropriate tabs below for more information. 

In addition, you will need to comply with the North Carolina state specific standard, 13 NCAC 07F .0701 -  .0716 - blasting and use of explosives. More related information can be found on the A-Z safety and health topics pages for blasting and explosives.