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New York State Department of Labor Safety and Health
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  • Subpart 39.7

Subpart 39.7

Blasting operations.

(a) Handling, placing and detonating explosives.

(1) The work of handling and placing explosives in preparation for a blast shall be performed only by a certified blaster or by persons under the supervision of a certified blaster.

(2) The detonation of explosives shall be performed only by a certified blaster.

Exceptions: 1.   The handling, placing and detonation of explosives in an underground mine may be performed by a designated person under the general supervision of a certified blaster.

2.   The use of a jet tapper, a jet perforator or a similar device utilizing not more than three ounces of explosives in manufacturing and drilling operations.

(b) Charging.  In charging holes for blasting, only hardwood or softwood rods, approved plastic poles or other non-sparking material shall be used for tamping. No person shall use a metal bar or rod for tamping or loading a hole with explosives, nor shall any rod or pole used for such tamping or loading have a metal tip. Non-sparking metal connectors may be used for jointed poles. Excessive or violent tamping shall be avoided and primers shall never be tamped. The ends of tamping rods shall be blunt and squared.

(c) Fuse requirements.  Any fuse which varies more than 10 percent from an average speed when burned unconfined in the open at sea level in three-foot lengths shall not be used. Any fuse that burns faster than 90 seconds per three-foot length with more than an allowable variation of 10 percent, when burned unconfined in the open at sea level, shall not be used.  Any 40 second/foot fuse length less than 36 inches shall not be used. This shall not apply to log-splitting wedges, the fuses for which may be not less than 12 inches in length. Fuses shall be cut and capped in safe, dry locations posted with "NO SMOKING" signs.

(d) Notice of blast. The certified blaster shall give timely notice of every blast to every person in danger thereof, and shall not detonate any blast until all persons have been removed to safe locations.

Exception:  In an underground mine the required notice of blast may be given by a designated person under the general supervision of a certified blaster.

(e) Maximum A.C. voltage of electric blast. The A.C. voltage used to detonate any blast shall not exceed 440 volts.

(f) Blasting operations during electrical storms. All blasting operations and any handling of explosives shall be stopped immediately upon the approach of an electrical storm, and all persons shall immediately retire to a place of safety.

(g) Blasting near radio frequency energy sources.

(1) Permanent installations. Prior to the assembly of electric blasting circuitry, the certified blaster shall check the locality for permanently installed radio frequency transmitters. If such installations exist in a proximate location which could affect the blasting area, such certified blaster shall cease blasting operations until assured that the transmitter will not cause a hazard in the blasting area due to the energy radiated. If a hazard is present, the certified blaster shall insure that the transmitter is not

operating and that appropriate personnel at the transmission site are notified so that the transmitter will not operate during the time of blasting operations.

(2) Mobile installation. The use of any two-way mobile communication unit in any blasting area during blasting operations is prohibited. In the blasting area, as well as along every road, street, highway or other thoroughfare adjacent to the blasting area where energy radiated could affect blasting circuits, warning signs shall be placed in conspicuous locations.  These signs shall be posted at least 350 feet away from any blasting operation.

(h) Assembly of blasting caps. Blasting caps shall be crimped to fuses only with implements designed for that specific purpose.

(i) Permanent electric blasting lines. Permanent electric blasting lines shall be properly supported, insulated and kept in good repair.

(j) Branch circuits. If branch circuits are used when blasts are fired from power circuits, safety switches located at safe distances from the blast areas shall be provided in addition to the main blasting switch.

(k) Blasting switches. Blasting switches shall be locked in the open position except when closed to fire and blast. Lead wires shall not be connected to the blasting switch until the shot is ready to be fired.

Exception: Permanent electric blasting lines.

(l) Electric circuits. Electric circuits from blasting switches to the blast area shall not be grounded.

(m) Detonating-cord knots. All detonating-cord knots shall be tight and all connections shall be kept at right angles to the trunklines.


Historical Note:    Sec. amds. filed: Mar. 23, 1972; June 22, 1973 eff. Aug. 1, 1973. Substituted new (a)and (d) and amended (g).


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