When operating drilling rigs mounted on vehicles such as trucks or crawlers to drill into rock or concrete, it's crucial for workers to be aware that this activity can generate respirable crystalline silica dust. Inhaling these small silica particles over time can lead to irreversible lung damage.

To address potential exposure, WorkCover Queensland advises the following controls in accordance with Appendix 4 of the Managing respirable crystalline silica in construction and manufacturing of construction elements code of practice 2022 (PDF, 1.71 MB) (the Code):

Use suitable engineering controls

Choose one of the following engineering control options:

• Implement a dust collection system featuring a close capture hood or shroud around the drill bit, coupled with a low-flow water spray to wet the dust at the discharge point.
• Operate the drilling rig from within an enclosed cab and use water for dust suppression on the drill.

Dust collection system

Dust management equipment for vehicle-mounted drills involves a movable duct connected to a close capture hood or shroud around the drill bit, along with a flexible rubber skirt that encloses the drill hole opening and captures cuttings.

Air is drawn from inside the shroud through a flexible duct to primary and secondary filter media. The primary filter or dust separator often incorporates a self-cleaning back-pulse feature that disposes of collected particles to the ground.

Secondary release of particles to the air is minimized by a low-flow water spray at the discharge point, and retrofitting these features is possible.

Effective use of dust collection systems requires good design and maintenance practices, operated by skilled and properly trained personnel.

Wet methods

Utilize an enclosed cab along with applying water to the drill bit during cutting to reduce dust.

Drill operators using vehicle-mounted rigs with enclosed cabs can minimize silica exposure by remaining inside the cab during drilling.

The cab should:

• Be well-sealed and well-ventilated using positive pressure.
• Have properly functioning door jambs, window grooves, powerline entries, and other joints that are tightly sealed.
• Include heating and air conditioning so operators can keep windows and doors closed.
• Be regularly maintained and cleaned to prevent settled dust from becoming airborne inside the enclosure.

Select appropriate respiratory protective equipment (RPE)

RPE is not required while using vehicle-mounted drilling rigs for rock or concrete.