Loading explosives procedures

Procedures that permit safe and efficient loading must be established before loading begins. Employers and blasters must set up and follow written or clearly communicated loading procedures to ensure the work is done safely and efficiently, as required by 1926.905(a).

• Put the procedures where crews can see or access them (briefing, written plan, or checklist).
• Include steps for hole checks, materials handling, personnel roles, and emergency actions.
• Train all loading personnel on those procedures before work starts.

Drill holes must be large enough to admit the explosive cartridges freely. Ensure each drill hole is sized so cartridges can be inserted without forcing or damaging them, as required by 1926.905(b).

• If cartridges bind, the hole is too small—do not force cartridges into place.
• Re-drill or ream holes that are undersized to avoid damage to explosives and unsafe loading.

Only wood rods or plastic tamping poles without exposed metal parts may be used for tamping, and violent tamping must be avoided. Nonsparking metal connectors are permitted for jointed poles, as stated in 1926.905(c).

• Use nonmetallic tamping poles or wooden rods to prevent sparks.
• Avoid heavy or violent blows that could damage charges or create unsafe conditions.
• Nonsparking metal connectors are allowed only for joining pole sections, not as exposed metal tamping ends.

No, the primer shall never be tamped. The standard explicitly prohibits tamping the primer during loading operations, per 1926.905(c).

• Place primers according to manufacturer and blaster procedures, but do not tamp them.
• Tamping primers risks initiation and serious injury—use approved methods to seat primers.

No, only holes that are to be fired in the next round shall be loaded. The rule forbids loading any holes except those scheduled for the immediate next round, per 1926.905(d).

• Plan blast rounds so loading is limited to the next sequence of holes.
• This reduces risk of misfires, unauthorized access, and unattended charges.

All remaining explosives and detonators must be returned immediately to an authorized magazine after loading. This is required by 1926.905(d).

• Do not leave unused explosives or caps at the blast site.
• Use authorized magazines and follow inventory controls when returning materials.

Drilling shall not be started until all remaining butts of old holes are examined for unexploded charges, and any found must be refired before work proceeds. This requirement is in 1926.905(e).

• Always inspect the ends (butts) of previous holes for signs of unexploded charges before beginning new drilling.
• If unexploded charges are found, follow safe refiring procedures and confirm detonation before resuming drilling.

No person shall be allowed to deepen drill holes which have contained explosives or blasting agents. The standard prohibits anyone from deepening such holes, as stated in 1926.905(f).

• If deeper drilling is needed, consult qualified blasting personnel for safe alternatives (such as re-drilling adjacent holes or other engineering controls) rather than deepening existing charged holes.

No, explosives or blasting agents shall not be left unattended at the blast site. The rule requires that they be attended and controlled, per 1926.905(g).

• Always keep explosives under the control of authorized personnel until they are returned to a magazine or fired.
• Unattended explosives increase the risk of theft, tampering, or accidental initiation.

Machines and tools not used for loading explosives must be removed from the immediate location of holes, and equipment shall not be operated within 50 feet of loaded holes. These requirements are in 1926.905(h).

• Keep only necessary loading tools at the immediate hole area.
• Maintain at least a 50-foot exclusion zone for operating equipment when holes are loaded to reduce risk of accidental initiation.

No activity other than that which is required for loading holes with explosives shall be permitted in a blast area. The standard restricts activities to loading tasks only, as stated in 1926.905(i).

• Prohibit unrelated work, pedestrian traffic, and recreational activities in the blast area.
• Limit personnel in the area to authorized loading crew members and supervisors.

Powerlines and portable electric cables used by equipment being used shall be kept a safe distance from explosives being loaded, and cables near the blast area shall be deenergized and locked out by the blaster. These controls are required by 1926.905(j).

• Maintain safe clearances between energized lines/cables and explosives.
• Deenergize and lock out portable cables in the blast area; have the blaster verify and control electrical sources.

Holes must be checked prior to loading to determine depth and conditions, and if a hole has been loaded but the explosives failed to detonate, there shall be no drilling within 50 feet of that hole. This is required by 1926.905(k).

• Measure and verify hole depth and condition before inserting explosives.
• After a misfire, enforce a 50-foot no-drilling zone until the failed charge is addressed safely.

When loading a long line of holes with more than one crew, the crews shall be separated by a practical distance consistent with efficient operation and supervision. This spacing requirement is stated in 1926.905(l).

• Separate crews enough to reduce mutual risk but keep them close enough for supervision and coordination.
• Define clear zones for each crew to prevent interference and accidental exposure to another crew's loading activities.

No, explosives shall not be loaded or used underground in the presence of combustible gases or combustible dusts. The standard prohibits such use, per 1926.905(m).

• Test and monitor underground atmospheres for combustible gases/dusts before any loading.
• If combustible atmospheres are present, ventilate or eliminate the hazard before any explosive work proceeds.

Only explosives in Fume Class 1 may be used by default, but explosives in Fume Class 2 or Fume Class 3 may be used if adequate ventilation has been provided. This is required by 1926.905(n).

• Prefer Fume Class 1 explosives in most situations.
• If using Fume Class 2 or 3, ensure documented, effective ventilation that controls fumes to safe levels before use.

All blast holes in open work must be stemmed to the collar or to a point which will confine the charge. The standard requires thorough stemming to confine the explosive force, per 1926.905(o).

• Stem holes fully to the surface collar or to the confinement depth recommended for the charge.
• Proper stemming reduces airblast, flyrock, and improves fragmentation control.

Warning signs indicating a blast area must be maintained at all approaches, and the lettering must be at least 4 inches in height on a contrasting background. This signage requirement is in 1926.905(p).

• Place legible signs at every approach to prevent unauthorized entry.
• Use clear wording and contrast so signs are visible from a safe distance.

No, a bore hole shall never be sprung when it is adjacent to or near a hole that is loaded, and flashlight batteries shall not be used for springing holes. These prohibitions are stated in 1926.905(q).

• Do not attempt to spring (open or ream) any hole next to a loaded hole to avoid disturbing nearby charges.
• Use approved, safe methods for springing holes away from loaded areas; do not use flashlight batteries as an initiation source.

Drill holes which have been sprung or chambered and are not water-filled shall be allowed to cool before explosives are loaded. The cooling requirement is in 1926.905(r).

• Wait until the rock and surrounding materials have cooled to avoid changing explosive behavior or creating unsafe conditions.
• Document cooling intervals and verify temperature before loading.

No, no loaded holes shall be left unattended or unprotected. The standard requires that loaded holes be supervised and protected, as stated in 1926.905(s).

• Provide guards, barriers, signage, or continuous attendance to prevent accidental disturbance or unauthorized access.
• Ensure the blaster or an authorized person is assigned responsibility until firing or safe removal.

The blaster must keep an accurate, up-to-date record of explosives, blasting agents, and blasting supplies used in a blast and maintain an accurate running inventory of all explosives and blasting agents stored on the operation. These recordkeeping and inventory requirements are in 1926.905(t).

• Track amounts used per blast, serial numbers (if applicable), dates, and personnel involved.
• Maintain on-site inventory records for all magazines and stored explosives and reconcile regularly.

When loading blasting agents pneumatically over electric blasting caps, semiconductive delivery hose must be used and the equipment shall be bonded and grounded. This electrical-control requirement is stated in 1926.905(u).

• Use only semiconductive hose rated for pneumatic delivery with electric caps present.
• Bond and ground the hose and pneumatic equipment to prevent static electricity buildup and accidental initiation.