Tunnel Dust Management

Tunnel construction generates high concentrations of dust from rock cutting, shotcreting, drilling, and haulage.
Dust in tunnels disperses slowly due to the enclosed environment and limited natural ventilation.
Respirable crystalline silica (RCS) from rock and concrete is the primary health hazard in tunnel dust.
The workplace exposure limit for RCS is 0.1 mg/m³ — tunnel operations frequently approach or exceed this level.
Ventilation systems including forced fresh air supply and exhaust extraction are essential for dust control.
Water suppression at the face, on conveyors, and at transfer points reduces dust generation significantly.
Vehicle emissions from diesel engines in tunnels combine with mineral dust to create a complex exposure.
Personal dust monitoring using gravimetric samplers measures actual worker exposure during a shift.
Enclosed cabs with filtered air supply protect plant operators from the highest dust concentrations.
Health surveillance including lung function testing is mandatory for all tunnel workers exposed to dust.

Silicosis risk	Tunnel workers face intense RCS exposure — silicosis can develop after relatively short periods in poorly controlled environments.
Enclosed environment	Dust concentrations in tunnels build up rapidly because the enclosed space prevents natural dispersal.
Legal duty	COSHH 2002 requires dust exposure in tunnels to be assessed, controlled, and monitored to protect workers.

Do

Don't

Operate ventilation systems continuously during all dust-generating tunnel activities
Use water suppression at the tunnel face, on conveyors, and at muck transfer points
Monitor dust levels using personal gravimetric samplers during each shift
Provide RPE rated for RCS to all tunnel workers during high-dust operations
Enrol all tunnel workers in health surveillance including lung function testing
Use enclosed cab plant with filtered air supply for operators at the tunnel face
Maintain ventilation equipment and check airflow rates at the start of each shift
Dampen haul roads within the tunnel to reduce re-entrainment of settled dust
Brief all tunnel workers on the dust hazards and the controls in place
Review dust monitoring results regularly and improve controls where levels are high

DON'T work in the tunnel heading without the ventilation system operating
DON'T remove RPE during dusty operations because it feels uncomfortable
DON'T dry sweep dust in tunnels — use vacuum extraction or damp methods only
DON'T allow diesel vehicles to idle unnecessarily inside the tunnel
DON'T ignore coughing, breathlessness, or chest tightness — report symptoms promptly
DON'T skip personal dust monitoring — it provides the evidence of actual exposure
DON'T use compressed air to blow dust off equipment or surfaces in the tunnel
DON'T bypass or reduce ventilation capacity to save energy or reduce noise
DON'T allow dust to accumulate on walkways, equipment, and surfaces in the tunnel
DON'T assume RPE alone is sufficient — engineering controls must be the priority

See also: Respirable Crystalline Silica (RCS) | Tunnelling Safety Awareness

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