Learn how the construction standard requires loading, electric and fuse initiation, detonating cord, firing, post-blast inspection and misfires to be handled by the blaster and blasting crew.
Based on OSHA 29 CFR 1926.905 through 1926.911 (construction blasting) · about 8 min read
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Procedures first. Procedures that permit safe and efficient loading must be established before loading is started.
Check each hole. Holes are checked before loading to determine depth and conditions.
Load only the next round. No holes are loaded except those to be fired in the next round of blasting.
Return what is left. After loading, all remaining explosives and detonators go immediately back to an authorized magazine.
Never unattended. No explosives or blasting agents may be left unattended at the blast site, and no loaded holes may be left unattended or unprotected.
Tamping. Use only wood rods or plastic tamping poles without exposed metal parts. Nonsparking metal connectors may be used for jointed poles. The primer shall never be tamped.
Equipment. Equipment shall not be operated within 50 feet of loaded holes.
Only loading in the blast area. No activity of any nature other than that required for loading holes with explosives is permitted in a blast area.
Cables. Cables in the proximity of the blast area shall be deenergized and locked out by the blaster.
Signs. Warning signs indicating a blast area must be maintained at all approaches. Lettering shall not be less than 4 inches in height on a contrasting background.
Records. The blaster keeps an accurate, up-to-date record of what was used in a blast and an accurate running inventory of explosives and blasting agents stored on the operation.
Examine old holes. Drilling is not started until all remaining butts of old holes are examined for unexploded charges. If any are found, they shall be refired before work proceeds.
Do not deepen. No person shall be allowed to deepen drill holes which have contained explosives or blasting agents.
Failed charges. Where a hole was loaded but the explosives failed to detonate, there shall be no drilling within 50 feet of the hole.
Not where it is dangerous. Electric blasting caps shall not be used where sources of extraneous electricity make their use dangerous.
Keep leg wires shunted. Blasting cap leg wires are kept short-circuited (shunted) until they are connected into the circuit for firing.
Survey first. Before adopting any system of electrical firing, the blaster conducts a thorough survey for extraneous currents. All dangerous currents shall be eliminated before any holes are loaded.
Matching caps. In any single blast using electric blasting caps, all caps shall be of the same style or function, and of the same manufacture.
The blaster is in charge of the machines. No other person shall connect the leading wires to the machine.
One person fires. In electrical firing, only the person making the leading wire connections fires the shot.
Connect from the hole back. All connections are made from the bore hole back to the source of firing current. The leading wires remain shorted and are not connected to the blasting machine or other source of current until the charge is to be fired.
After the shot. Leading wires are immediately disconnected from the machine and short-circuited.
When fuse is used. Safety fuse shall only be used where sources of extraneous electricity make the use of electric blasting caps dangerous.
Unused caps. No unused cap or short capped fuse is placed in any hole to be blasted. Such unused detonators are removed from the working place and destroyed.
Carrying. No one is permitted to carry detonators or primers of any kind on their person.
Length. The minimum length of safety fuse is as required by State law, but not less than 30 inches.
People and numbers. At least two people must be present when multiple cap and fuse blasting is done by hand lighting. Not more than 12 fuses may be lighted by each blaster with hand lighting devices, but a group lighted as one by igniter cord or a similar device may be considered as one fuse.
No drop fuse. The method of dropping or pushing a primer or any explosive with a lighted fuse attached is forbidden.
Time to get clear. Consider the length and burning rate of the fuse, and always allow sufficient time, with a margin of safety, for the blaster to reach a place of safety.
Respect. Detonating cord is handled and used with the same respect and care given other explosives.
Cut from the spool. The line of cord extending out of a bore hole or from a charge is cut from the supply spool before loading the rest of the hole or placing additional charges.
Layout. All trunklines and branchlines must be free of loops, sharp kinks or angles that direct the cord back toward the oncoming line of detonation.
Inspect. All detonating cord connections are inspected before firing the blast.
Detonators last. Detonators for firing the trunkline shall not be brought to the loading area nor attached to the cord until everything else is in readiness for the blast.
Signal code. A code of blasting signals equivalent to Table U-1 is posted in one or more conspicuous places. All employees must familiarize themselves with the code and conform to it.
Loud warning. Before a blast is fired, the blaster in charge gives a loud warning signal, having made certain that all surplus explosives are in a safe place and all employees, vehicles and equipment are at a safe distance or under sufficient cover.
Traffic. Flagmen are safely stationed on highways that pass through the danger zone so as to stop traffic during blasting operations.
Timing. It is the duty of the blaster to fix the time of blasting.
Disconnect right away. Immediately after the blast, the firing line is disconnected from the blasting machine, or where power switches are used, they are locked open or in the off position.
Let fumes clear. Sufficient time must be allowed for smoke and fumes to leave the blasted area before returning to the shot. In tunnels that is not less than 15 minutes.
Blaster inspects first. The blaster inspects the area and the surrounding rubble to determine if all charges have been exploded before employees are allowed to return to the operation.
Safeguard the zone. If a misfire is found, the blaster provides proper safeguards for excluding all employees from the danger zone.
Only necessary work. No other work is done except what is necessary to remove the hazard of the misfire, and only the employees necessary to do that work remain in the danger zone.
Do not dig it out. No attempt shall be made to extract explosives from any charged or misfired hole. A new primer is put in and the hole is reblasted.
If reblasting is itself a hazard, the explosives may be removed by washing out with water, or blown out with air where the misfire is under water.
Cap and fuse. If there are any misfires while using cap and fuse, all employees remain away from the charge for at least 1 hour.
No digging or drilling. No drilling, digging or picking is permitted until all missed holes have been detonated or the authorized representative has approved that work can proceed.
Fact-checked against the regulation text on October 09, 2026. This certificate records completion of awareness training based on OSHA 29 CFR 1926.905, 1926.906, 1926.907, 1926.908, 1926.909, 1926.910 and 1926.911. It is not an OSHA card or license and does not qualify anyone to handle explosives. These sections have no separate training requirement. Your employer must still post a code of blasting signals equivalent to Table U-1 in one or more conspicuous places at the operation and require all employees to familiarize themselves with the code and conform to it (29 CFR 1926.909(a)). Check the State and local requirements that apply to blasters.
This guide explains the rule in plain words. Always read the regulation itself and your employer's site-specific procedures.