Never Assume: How to Safely Qualify a New Explosive Product

Petr Explosives Group | Technical Blog

In the explosives industry, assumptions are one of the leading causes of misfires, inconsistent fragmentation, excessive vibration, and preventable safety incidents. Every year, experienced blasters encounter issues simply because they treat a new product as interchangeable with those they have used previously.

Whether you are introducing a new emulsion, ANFO blend, water gel, detonator, or electronic initiation system, general familiarity with explosives is not the same as specific knowledge of that product. Each formulation and system has unique characteristics — density, velocity of detonation (VOD), sensitivity, water resistance, sleep time, and compatibility requirements. A structured qualification process is not bureaucracy; it is a fundamental professional practice that protects personnel, equipment, and blast outcomes.

At Petr Explosives Group, we follow a disciplined approach to product qualification. Here is our recommended process:

1. Thoroughly Review the Technical Data Sheet (TDS)
Before loading a single hole, read the manufacturer’s Technical Data Sheet from cover to cover. Focus specifically on:

– Product density and VOD
– Water resistance rating
– Temperature limitations
– Maximum recommended sleep time
– Primer size and placement recommendations
– Approved initiation methods
– Compatibility with other explosives
– Storage and handling requirements

The majority of misfires with new products result from use outside the manufacturer’s specified conditions—conditions clearly documented in the TDS.

2. Consult the Manufacturer’s Technical Representative
A brief conversation with the technical representative can prevent significant operational setbacks.

Key questions to ask include:

– What primer and booster sizes do you recommend?
– Top or bottom priming preference?
– Any known dead-pressing risks?
– Maximum recommended hole depth and water column?
– Documented incompatibilities?
– Realistic sleep time under field conditions?

Manufacturers possess extensive field data. Leverage this expertise early.

3. Conduct a Controlled Small-Scale Test Blast
Never transition directly to full production with an unproven product. Begin with a limited test of 1–5 holes using standard burden, spacing, and loading parameters. Evaluate critical performance metrics:

– Initiation reliability
– Fragmentation size and uniformity
– Ground vibration levels
– Flyrock potential
– Fume generation and quality
– Toe conditions post-blast

The insights gained from these initial holes provide high-value data that far outweighs the minimal time investment.

4. Verify Primer Placement and Configuration
Incorrect priming remains one of the most frequent causes of misfires. For every test hole, physically confirm:

– Correct primer orientation and depth
– Appropriate booster size
– Proper detonator seating
– Undamaged and correctly positioned downline

In deeper holes, bottom priming is often preferred, as it allows the detonation wave to travel upward through the entire explosive column, minimizing cutoff risks.

5. Confirm Initiation System Compatibility
Never assume compatibility between components from different manufacturers. Verify all interfaces before firing, including:

– Detonator-to-booster compatibility
– Booster-to-bulk explosive performance
– Surface delay and downline integration
– Shock tube lengths and connector types
– Electronic detonator programming and timing

A configuration that performs well in one setup may fail in another.

6. Perform a Comprehensive Pre-Fire Hole Inspection
Before connecting the initiation system, conduct a detailed inspection of every loaded hole. Checklist items should include:

– Achieved hole depth
– Loaded explosive quantity
– Primer location and condition
– Stemming height and material
– Undamaged shock tube or detonating cord
– Correct delay assignment

This step allows no shortcuts.

7. Closely Monitor Sleep Time
Explosive products can degrade in the borehole, particularly under wet or high-temperature conditions. Monitor for:

– Water infiltration and desensitization
– Product settling or separation
– Dead-pressing due to confinement
– Progressive loss of sensitivity near maximum sleep time

Always remain within the manufacturer’s rated sleep time. When conditions are marginal, prioritize firing earlier.

8. Conduct a Detailed Post-Blast Analysis
After each test blast, document key observations:

– Presence of any misfires or unfired holes
– Remaining toe
– Fragmentation quality and distribution
– Evidence of cutoffs
– Airblast and vibration measurements
– Flyrock distance and direction
– Fume characteristics

This data becomes critical for assessing product suitability and informing future decisions.

9. Maintain a Formal Trial Log
Record every test in a structured log. A recommended format includes:

Over time, this log develops into a valuable site-specific knowledge base.

The Professional Standard

A professional blaster treats every new explosive product as unproven until it has demonstrated consistent, reliable performance under actual site conditions. The process is straightforward:

1. Review the Technical Data Sheet
2. Consult the manufacturer
3. Execute small-scale test blasts
4. Verify priming and placement
5. Inspect every loaded hole
6. Document results thoroughly
7. Scale up only after multiple successful tests

This disciplined approach is not excessive caution — it is how leading operations maintain outstanding safety records, minimize regulatory exposure, and consistently deliver the fragmentation quality their customers demand.

“When you truly know your product, you control your blast. When you assume, you surrender that control to chance.”

Petr Explosives Group provides expert technical guidance, product qualification support, and field training for quarry, mining, and construction blasting operations worldwide.

Have questions about qualifying a new explosive or initiation system? Contact our technical team today.