Dust Control During Drilling & Blasting

Dust Control During Drilling and Blasting: Stopping Silica Exposure at the Source of the Blast Pattern

Drilling and blasting are the starting point of production at every hard rock mine and quarry. They are also among the most concentrated sources of respirable crystalline silica dust on the entire site. The drill bit fractures rock at high energy, generating a plume of fine dust that exits the hole under compressed air pressure. The cuttings that accumulate around each drill collar are piles of freshly fractured material with extremely high respirable content. And the blast itself — when tonnes of explosive detonate simultaneously — sends a massive dust cloud into the atmosphere, carrying silica and other hazardous minerals across the site and beyond.

NIOSH documented 23 cases of silicosis among surface mine rock drillers in a single Alert, noting that two had already died from the disease and the remaining 21 may eventually die from silicosis or its complications. Every one of those cases was caused by exposure during drilling operations. The drill operators, their helpers, the shotfirers who load the holes, the service truck drivers who work in the pattern area, and any workers downwind are all exposed to dust that they cannot see at concentrations that can cause irreversible, fatal lung disease.

Despite this, drill and blast dust control remains one of the most neglected areas of mine site dust management. The water flush on the drill rig is considered sufficient. The cuttings piles are left untreated. The blast crew works in the pattern area without source control. And the blast itself is accepted as an unavoidable dust event.

None of this is acceptable under current Australian regulations. And none of it is necessary. This article covers the two-phase dust challenge of drilling and blasting, the regulatory obligations that apply, and the engineered solutions that control both phases at the source.

The Two-Phase Dust Challenge: During Drilling and After Drilling

Phase 1: Dust Generated During Drilling

Rotary blast hole drills use compressed air to flush cuttings from the hole as the bit advances through the rock. This high-velocity air stream exits the collar carrying a concentrated plume of freshly fractured dust. The dust is generated continuously for the duration of each hole — typically 5–20 minutes per hole depending on depth and rock hardness — and a drill rig may complete 20–60 holes per shift. The cumulative exposure for the drill operator across a full shift is substantial.

The standard engineering control is wet drilling — injecting water into the air stream to wet the cuttings and suppress the dust plume as it exits the collar. Wet drilling reduces visible dust significantly but, as with all water-only suppression, it is least effective against the finest, most hazardous particles. Freshly fractured silica particles are hydrophobic at the microscopic level. They resist wetting by plain water, deflecting off droplets and remaining airborne. The drill rig may appear adequately dust-controlled visually while respirable silica concentrations in the operator’s breathing zone exceed the workplace exposure standard.

Dust collection systems — shrouds fitted around the drill collar connected to a collector mounted on the drill mast — are available on many modern rigs. NIOSH research documented that effective dry collector systems can reduce drill operator exposure by 90–99%. However, collector performance depends on maintenance (filter condition, shroud seal integrity, collector capacity) and many operations report that collector systems are poorly maintained, bypassed during operation, or not fitted to older rigs.

Phase 2: Dust Generated from Drill Cuttings After Drilling

When drilling is complete, the blast pattern is covered in piles of drill cuttings — one pile at each collar location, with as many as 200–600 holes in a single production blast pattern. Each pile is a mound of finely fractured rock with an extremely high proportion of respirable-sized particles. The cuttings are freshly generated, dry and loose. They sit on the bench surface, fully exposed to wind, vehicle traffic and foot traffic.

This is the phase that is almost universally neglected. The drilling crew moves off the pattern. The blast crew moves in to load the holes. Between drilling and loading, and during loading itself, the cuttings piles are generating dust every time the wind blows, every time a vehicle drives through the pattern, and every time a shotfirer walks between holes. The blast crew can spend hours working among these piles. Their exposure to respirable dust from the cuttings is cumulative across the entire loading period — and it is almost never monitored or controlled.

After blasting, the muck pile contains material fractured to a wide range of sizes. Loading operations (excavators and loaders) generate further dust as the material is dug, lifted and dropped into trucks. This post-blast dust is typically managed by the site’s general dust suppression programme (water trucks, spray systems) but the pre-blast cuttings exposure is not.

Drill and blast dust sources: exposure points and control gaps

The Regulatory Framework: Drill and Blast Is Not Exempt

Drill and blast activities are subject to the same workplace exposure standards and crystalline silica management obligations as every other dust source on the mine site.

Chapter 8A of the WHS Regulations (effective 1 September 2024) applies to all workplaces processing crystalline silica substances. Drilling into silica-bearing rock is explicitly a crystalline silica process. High-risk crystalline silica work requires a silica risk control plan. Workers must complete accredited crystalline silica training.

Queensland RS20 addresses dust management on surface coal mines, including mobile plant operations and processing activities that generate silica dust. Drill rigs operating on coal mines fall within the scope of RS20’s dust management requirements.

NSW Resources Regulator includes drill operations within the scope of its airborne contaminants guidance and compliance priorities. The May 2025 Technical Reference Guide covers exposure monitoring for all dust-generating activities, including drilling.

NIOSH Alert 92-107 specifically addresses silicosis prevention in rock drillers, documenting 23 cases and recommending engineering controls including effective dust collection, wet drilling with chemical additives, enclosed pressurised cabs, and management of cuttings piles.

The practical implication is that drill operators must be included in the site’s similar exposure group (SEG) structure for personal exposure monitoring, the drill rig must be equipped with functioning engineering controls, and the blast pattern area must be managed as a dust source — not left uncontrolled between drilling and blasting.

The Two-Pronged Solution: Activate the Water, Bind the Cuttings

Phase 1 Solution: GRT: 12X — Super-Activating the Drill Water

GRT: 12X is dosed into the drill rig’s water tank at ratios of 1:1,000 to 1:2,000 (soil-dependent). The product modifies the surface tension and ionic charge of the drilling water so that it actively attracts and saturates the fine, hydrophobic dust particles generated during drilling. Instead of the water and dust repelling each other — which is what happens with plain water on freshly fractured silica surfaces — the activated water captures the respirable fraction and forces it to drop out of suspension.

Independently verified by one of Australia’s leading universities to be 12 times more effective at capturing dust than water alone, GRT: 12X targets the specific particle size range that causes silicosis and coal workers’ pneumoconiosis. It does not affect ore properties, does not interfere with drill and blast activities, and does not alter the explosive performance of the charged holes. The product is non-toxic, biodegradable and safe for workers.

An additional operational benefit is hole stability. The activated water creates a more cohesive cuttings structure around the collar, reducing the risk and cost of hole collapse — a common and expensive problem on mine sites where unstable ground conditions or high water tables cause holes to fail before they can be loaded.

Phase 2 Solution: GRT: DC Binder — Locking Down the Blast Pattern

GRT: DC Binder is a polymer binder that is sprayed across the blast pattern after drilling is complete, forming a tough surface crust over the drill cuttings piles and the exposed bench surface between them. The crust binds the fine, hazardous particles in place, preventing them from becoming airborne when disturbed by wind, vehicle traffic or the movement of the blast crew as they walk through the pattern loading holes.

The product is applied by water truck or spray unit across the entire pattern area in a single pass. At a cost of approximately $0.10 per square metre, it provides continuous dust suppression for the duration of the loading period — which may be hours or days depending on the pattern size and loading schedule. The crust remains effective until the blast disrupts it, at which point the material is fragmented and the cuttings are incorporated into the muck pile.

For shotfirers, rig operators and service truck drivers who spend extended periods in the blast pattern area, DC Binder addresses the near-total control gap that exists on most mine sites. These workers are on the ground, in direct contact with the cuttings, for the entire loading period. Without surface treatment, their cumulative respirable dust exposure across a shift of hole loading can be substantial — and it is almost never captured by the site’s routine personal monitoring programme because drill and blast crews are often excluded from the standard SEG structure.

Complementary Action: A Complete Drill and Blast Dust Control System

GRT: 12X and GRT: DC Binder are designed to work as a complementary system addressing both phases of the drill and blast dust challenge.

During drilling: 12X is dosed into the drill rig’s water tank. As each hole is drilled, the activated water captures the respirable dust generated at the collar, preventing it from becoming airborne and exposing the drill operator and nearby workers. The cuttings that accumulate around the collar are pre-wetted with activated water, reducing their initial dust generation potential.

After drilling, before blasting: DC Binder is sprayed across the entire blast pattern by a water truck or spray unit. The polymer crust locks down every cuttings pile and the exposed bench surface between them. The blast crew works in the pattern for the duration of the loading period with the cuttings piles sealed and not generating dust.

During blasting: The blast destroys the polymer crust along with the rock. The DC Binder treatment has no effect on blast performance, fragmentation, explosive efficacy or muck pile characteristics. The polymer is a surface treatment, not a bulk additive — it affects only the top few millimetres of the cuttings piles and bench surface.

After blasting: The muck pile is managed by the site’s standard suppression programme — water trucks with Haul-Loc for road dust, Activate for crusher and conveyor sprays. The drill and blast system hands off to the production suppression system seamlessly.

Practical Implementation: Deploying the System on Your Site

1. Dose GRT: 12X into drill rig water tanks. The product is supplied as a liquid concentrate. Add at the specified ratio (1:1,000 to 1:2,000 depending on material) each time the rig’s water tank is filled. No modification to the rig is required. The existing wet drilling system delivers the activated water.
2. Spray DC Binder after drilling completion. Once the last hole is drilled and the drill rig moves off the pattern, a water truck sprays DC Binder across the entire pattern area. Coverage must include every cuttings pile and the bench surface between holes. Application takes one pass of the water truck across the pattern.
3. Allow crust formation. DC Binder forms a surface crust as it dries — typically within 30–60 minutes depending on temperature and humidity. The blast crew can begin loading once the crust has formed. Traffic across the treated surface does not break the crust under normal foot and light vehicle movement.
4. Monitor exposure. Include drill operators and blast crew in the site’s personal exposure monitoring programme. Compare results against the baseline established before 12X and DC Binder introduction. The difference quantifies the control effectiveness and provides the evidence base for the site’s silica risk control plan.
5. Document and report. Record the products used, dosing rates, application dates and areas treated. This documentation demonstrates compliance with Chapter 8A obligations and provides auditable evidence that drill and blast dust is managed as an engineering control, not left as an uncontrolled source.

The Blast Pattern Is Not a Dust-Free Zone — Treat It Like Any Other Dust Source

Every mine site invests in dust control on haul roads, at crushers, on stockpiles and across operational areas. The blast pattern — where some of the highest silica concentrations on the entire site are generated — is the area most frequently left untreated. The cuttings piles sit in the open, generating dust with every gust of wind, for hours or days before the blast.

NIOSH documented fatal silicosis in rock drillers. The regulatory framework in Australia requires engineering controls for every crystalline silica process on the mine site. The technology to control drill and blast dust at the source is available, proven and cost-effective: GRT: 12X at 1:1,000 to 1:2,000 in the drill rig’s water tank, and GRT: DC Binder at $0.10 per square metre across the blast pattern.

For drill and blast managers, shotfirers and safety managers responsible for protecting the workers who spend their shifts in the pattern area, the question is straightforward: if you control dust on the haul road, at the crusher and on the stockpile, why is the blast pattern — where the dust starts — the one area you leave uncontrolled?

Sources and References

NIOSH: Alert 92-107: Preventing Silicosis and Deaths in Rock Drillers — 23 silicosis cases, 2 deaths

NIOSH / CDC: Engineering Controls Database: Best Practices for Dust Control — Drill Dust Collection Systems

Safe Work Australia: Stronger Regulation of Crystalline Silica Substances — Chapter 8A, 1 September 2024

Australian Mining: GRT Combats Drill and Blast Dust — 12X and DC Binder launch, Daniel Grundy quotes

Dust Safety Science: Mining Dust Control: Comprehensive Strategies (July 2024) — drilling and blasting dust overview

Oizom: Dust Control in Mines: Methods, Sources, Solutions — drilling and blasting dust generation

GRT: Drill and Blast Dust Control — Industry Guide

GRT: GRT: 12X — drill water activation, 12× more effective than water, 1:1,000–1:2,000 dosing

GRT: GRT: DC Binder — blast pattern polymer binder, $0.10/m²

GRT: Why Water Sucks When It Comes to Dust Suppression — 12X + DC Binder two-pronged system

GRT: GRT: Haul-Loc

GRT: Dust Suppression Solutions — Activate, product range