On site, the dust you can see is not usually the dust that hurts you most. The smallest particles travel deepest into the lungs, stay airborne longest, and are hardest to control. Understanding particle size is the fastest way to choose controls that actually reduce exposure.

Particle size and where it ends up

PM10 is inhalable and irritates the nose and throat. PM4 and smaller are respirable and reach the gas-exchange region of the lungs. PM2.5 and PM1 can remain suspended for hours and are easily re‑agitated. Respirable crystalline silica (RCS) from cutting masonry is largely in the PM4 range and is linked to silicosis and lung cancer. In short: as size drops, risk rises.

Match controls to the particle

1) Capture at source

• Use water suppression on masonry and tile cutting; slow the cut to reduce fine particle generation.
• Fit tight tool shrouds and local exhaust ventilation (LEV). Check airflow under load, not free‑air numbers.
• Choose the correct filter class on tool vacuums (M‑Class for most wood and general dust; H‑Class for high‑hazard dusts).

2) Capture in the air

• Use air scrubbers or negative air machines sized to the room volume and leakage. For fine or carcinogenic dusts such as RCS, use H14 filtration.
• Seal doorways and create pressure differentials to prevent migration to clean areas.

3) Capture on surfaces

• Avoid sweeping and compressed air, which launch PM2.5/PM1 back into the breathing zone.
• Vacuum with industrial units that maintain suction as filters load; schedule filter checks and bag changes.

Verify with measurement

Use a particulate monitor to compare baseline, during-task, and post-control conditions. Track PM1/PM2.5/PM4 trends and adjust controls until readings stabilise at the lowest achievable level. For RCS, rely on task-based sampling for compliance decisions.

Practical takeaways

• Assume small particles drive the health risk; plan controls accordingly.
• Prioritise source capture with shrouds, LEV and water.
• Use H14 air filtration when targeting respirable and carcinogenic dusts.
• Replace sweeping with industrial vacuuming; maintain filters.
• Measure, review, and refine until exposure is demonstrably reduced.

The control that fits the particle is the control that works. Build your plan around particle size and you will remove more risk with less effort.