Clean air is not a slogan; it is a measurable safety outcome. On UK sites, airborne particulate drives respiratory disease, reduced productivity, and rework. Treating “clean air” as a metric focuses teams on prevention, not just PPE. For context, the HSE WEL for respirable crystalline silica (RCS) is 0.1 mg/m³; many routine tasks can exceed this without controls.

Turn air quality into a site KPI

Define practical targets by task and area. Use PM measures (PM10, PM2.5, PM1) as leading indicators and mg/m³ for risk-based thresholds. Set trigger levels that prompt action before limits are approached, and make supervisors responsible for response times.

Measure what matters

Deploy a particulate monitor where people breathe: 1–1.5 m height, upwind/downwind of the process. Log data continuously and spot-check with a hand-held meter when tasks change. Verify “airflow under load” on air scrubbers and LEV rather than free-air figures, and keep filters matched to the hazard (H13/H14 for fine or carcinogenic dusts).

Apply the three-layer control plan

1) Capture at source

• Fit tool-mounted extraction and water suppression.
• Reduce speed/feeds and cut outdoors where possible.
• Design out dry cutting and high-energy abrasion.

2) Capture in the air

• Use air scrubbers or negative air machines sized by the actual room volume and target air changes per hour.
• Duct to create flow across the workface; avoid dead zones.

3) Capture on surfaces

• Vacuum with M-Class or H-Class industrial vacuums; avoid sweeping and compressed air.
• Schedule filter checks and bag changes before performance drops.

Respond, verify, document

• Set alarm/action levels on monitors; pause work and correct controls when exceeded.
• Confirm with a second reading after adjustments.
• Record task, controls, readings, and corrective actions for COSHH evidence.

Practical takeaways

• Make PM and mg/m³ readings a daily briefing item.
• Use H14 filtration for respirable and carcinogenic dusts.
• Tie maintenance (filters, seals, ducting) to measured performance, not time alone.
• Report “air quality restored” alongside re‑start decisions.

When clean air is tracked like any other safety metric, controls stay active, exposures fall, and productivity improves without relying solely on respirators.