Misfire procedures in blasting

The blaster must provide proper safeguards to exclude all employees from the danger zone when a misfire is found. See 1926.911(a).

• Only the blaster (the person in charge of the blasting operation) is explicitly required to establish those safeguards.
• Safeguards can include barriers, signs, personnel to control access, and any other measures that keep employees out of the hazard area.

No. Only work necessary to remove the misfire hazard may continue, and only the employees needed to perform that work may remain in the danger zone. See 1926.911(b).

• Nonessential workers must be removed from the danger zone.
• Work unrelated to clearing the misfire is prohibited until the hazard is removed.

No. You must not attempt to extract explosives from any charged or misfired hole; instead, put in a new primer and reblast the hole. See 1926.911(c).

• Extracting a primer or explosive from a charged/misfired hole is prohibited.
• The required action is to insert a new primer and reblast, unless reblasting creates a hazard.

Explosives may only be removed if refiring poses a hazard; in that case, wash the explosives out with water or, if the misfire is under water, blow them out with air. See 1926.911(c).

• Washing out with water is allowed when refiring is hazardous and the hole is accessible.
• For underwater misfires, removal by blowing out with air is permitted.
• Any such removal should be done carefully and only by authorized personnel following the blaster's direction.

All employees must remain away from the charge for at least 1 hour when a misfire happens while using cap and fuse. See 1926.911(d).

• The person in charge of the blasting must direct handling of the misfire.
• After the 1-hour wait, wires must be carefully traced and a search conducted for unexploded charges before allowing personnel back in.

The person in charge of the blasting operation directs how misfires are handled. See 1926.911(d).

• That person is responsible for decisions about waiting periods, tracing wires, and searching for unexploded charges.
• Follow the person in charge’s instructions exactly to minimize risk.

It means all connected wires must be followed visually and/or physically to locate any unexploded charges before anyone re-enters the area. See 1926.911(d).

• Tracing ensures you find where the misfired circuit leads and identify any unfired charges.
• Use non-sparking tools and safe procedures advised by the person in charge while tracing wires.

No. Drilling, digging, or picking is not permitted until all missed holes have been detonated or an authorized representative has approved that work can proceed. See 1926.911(e).

• The authorized representative (for example, site safety officer, blaster, or other designated authority) must give approval before those activities begin.
• This prevents accidental disturbance of unexploded charges.

Only those employees necessary to remove the hazard of the misfire may remain in the danger zone. See 1926.911(b).

• Nonessential personnel must be evacuated.
• Keep the number of people in the danger zone to the minimum required to safely correct the misfire.

Proper safeguards include physical barriers, signage, designated safety personnel, and other measures that prevent access to the danger zone until the misfire hazard is removed. See 1926.911(a) and 1926.911(b).

• Barriers and warning signs clearly mark the danger zone.
• Trained personnel should control access and watch for unauthorized entry.
• Communication (radio/PA) to alert nearby crews is a recommended safeguard.

You must put in a new primer and reblast the misfired hole rather than attempting to remove the original explosive. See 1926.911(c).

• Do not dig out or pull the original primer or explosive charge from the hole.
• Repriming and reblasting is the standard remedial action unless refiring is unsafe.

If a misfire is under water and refiring is hazardous, the explosives may be removed by blowing them out with air. See 1926.911(c).

• Specialized equipment and procedures for underwater operations must be used.
• Only trained personnel should perform underwater removal using air blow-out methods.

Employees must stay away for at least 1 hour after a misfire when using cap and fuse to allow any delayed ignition risk to subside and to enable safe handling directed by the person in charge. See 1926.911(d).

• The one-hour wait reduces the danger of a delayed detonation.
• After the wait, the person in charge must direct tracing and searching for unexploded charges before re-entry.

The standard does not require a written permit before reblasting; it requires the blaster to provide safeguards and that only necessary employees perform the work. See 1926.911(a) and (b).

• Employers should follow any site-specific permits or company procedures when applicable.
• Even without a permit requirement in 1926.911, document procedures and approvals per company policy for accountability.

The person in charge of the blasting directs the search for unexploded charges, and all wires must be carefully traced as part of that search. See 1926.911(d).

• The blaster oversees the process and ensures qualified personnel perform the tracing and search.
• Use safe methods and keep nonessential workers clear of the area during the search.

The standard permits removal of explosives only by washing out with water or blowing them out with air (if under water); it does not authorize mechanical extraction. See 1926.911(c).

• Mechanical digging or extracting could disturb the charge and is not allowed by the text of the rule.
• Only the allowed methods (wash out with water; blow out with air for underwater misfires) should be used when refiring is unsafe.

Only the employees necessary to remove the misfire hazard are permitted to stay in the danger zone. See 1926.911(b).

• Keep the crew size minimal to reduce exposure to risk.
• Ensure those who remain are trained and briefed on the safe procedures to resolve the misfire.

An authorized representative must approve that work can proceed before drilling, digging, or picking may resume when missed holes are present. See 1926.911(e).

• The authorized representative could be the blaster, site safety officer, or another designated company official with authority.
• Approval should be documented per site procedures to confirm the area is safe.

No, the standard requires the blaster to provide proper safeguards to exclude employees but does not prescribe specific marking methods, leaving details to the blaster's judgment. See 1926.911(a).

• Common practices include flags, ropes, barricades, and signs to indicate the danger zone.
• Whatever method is chosen should clearly prevent unauthorized entry and be communicated to all personnel.

All employees must remain away from the charge for at least one hour; only the person in charge directs handling—this implies observation and handling are under their control, not left to unqualified non-blasting personnel. See 1926.911(d).

• Non-blasting personnel should not approach the charge during the waiting period.
• Any checks after the hour should be performed under the direction of the person in charge and by qualified individuals.

The person in charge should ensure everyone stays away for at least one hour, direct how the misfire will be handled, and ensure all wires are carefully traced and a search for unexploded charges is conducted. See 1926.911(d).

• Establish and enforce the exclusion zone.
• Plan and assign qualified personnel to trace wires and locate any unexploded charges after the waiting period.
• Approve any further actions, such as reblasting or approved removal methods.