Cement and aggregate silos generate significant dust during filling, venting and load-out. Uncontrolled emissions harm workers, foul equipment and create community complaints. A practical plan that prioritises prevention, then control, then housekeeping keeps sites safer and compliant with COSHH and HSE guidance.

Target the main release points

• Top filling: overfill and poor venting push dust through relief valves and gaskets.
• Load-out: open chutes and transfer points release plumes, especially in dry, windy conditions.
• Inspection hatches and flanges: worn seals leak under pressure.
• Conveyors and bucket elevators: uncovered sections and misaligned skirting shed fines.

Capture at source

• Use effective silo vent filters and maintain them. Check differential pressure weekly and clean or change media before restriction forces dust through weak points.
• Fit telescopic loading spouts with integral extraction on tanker and bulk load-out to keep flow enclosed.
• Seal what you can: replace hatch gaskets, repair cracked welds and align chute skirting to keep negative pressure effective.
• Apply water mist on aggregates at transfer points where feasible, but avoid adding moisture to cement transfer where it can cause set or blockage.

Control dust in the air

• Maintain slight negative pressure in filling bays and load-out sheds using local exhaust ventilation sized for under-load airflow, not free-air figures.
• Deploy air scrubbers in enclosed bays to reduce background PM10 and respirable dust; choose HEPA that meets H14 when dealing with respirable crystalline silica (RCS).
• Keep doors and roller shutters on a close-when-not-in-use regime to stabilise airflow paths.

Housekeeping without re-agitating

• Avoid sweeping and compressed air. Use industrial vacuums with M-Class or H-Class filtration for fine cement dust. Empty and bag waste with minimal handling.
• Schedule cleaning around production, starting high to low to prevent re-soiling.

Monitoring, maintenance and compliance

• Fit reliable level instruments and test pressure relief valves to prevent overfill blowouts.
• Walk the system after every delivery during high season; look for tell-tale dust halos around flanges and vents.
• Spot-check air quality in load-out areas using a particulate monitor. Use results to trigger filter changes or process adjustments.
• Under COSHH, control exposures as low as reasonably practicable. Remember HSE WELs: respirable dust (4 mg/m³), inhalable dust (10 mg/m³), and RCS at 0.1 mg/m³.

Practical takeaways

• Keep silos tight: seals, gaskets and vent filters in good order.
• Enclose load-out with telescopic spouts and local extraction.
• Ventilate bays for negative pressure and use H14 filtration where RCS is present.
• Vacuum, don’t sweep; service filters based on differential pressure and observed loading.
• Use PM readings and delivery checks to catch issues early.

Small improvements at each release point add up. When venting, load-out and housekeeping are disciplined, silo dust stays contained and productivity improves.