DUS/General/TBT-DUS-002

Respirable Crystalline Silica (RCS)

Dust & SilicaGeneralRespirable Crystalline Silica (RCS)

All Categories/Dust & Silica/General/Respirable Crystalline Silica (RCS)

Respirable Crystalline Silica (RCS)

Toolbox Talk Record

Ref: TBT-DUS-002  |  Issue: 1  |  Date: March 2026
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What?

  • Respirable crystalline silica is a fine dust released when cutting, drilling, grinding, or demolishing concrete, stone, and brick.
  • RCS particles are so small they penetrate deep into the lungs where the body cannot remove them, causing permanent scarring.
  • Silicosis is an incurable lung disease caused by RCS exposure — it progressively destroys lung tissue and reduces breathing capacity.
  • RCS exposure also causes lung cancer and chronic obstructive pulmonary disease (COPD) in construction workers.
  • The UK workplace exposure limit for RCS is 0.1 mg/m³ — this is exceeded quickly without proper dust controls in place.
  • Around 500 construction workers die each year from RCS-related diseases including silicosis and lung cancer.
  • High-risk tasks include cutting concrete blocks, drilling concrete, angle grinding stone, and road planing operations.
  • On-tool water suppression reduces RCS exposure by up to 90% and should be the primary control for cutting operations.
  • On-tool dust extraction with an H-class vacuum captures RCS at source before it becomes airborne.
  • RPE is the last resort — it must be face-fit tested and worn correctly when engineering controls are not sufficient.

Why?

Incurable diseaseSilicosis cannot be treated or reversed — once lung tissue is scarred by silica dust, the damage is permanent and progressive.
Cancer riskRCS is classified as a human carcinogen — regular uncontrolled exposure significantly increases your risk of developing lung cancer.
Invisible at harmful levelsThe most dangerous RCS particles are too small to see — dust that is invisible is the dust that kills you.
Do Don't
  • Use on-tool water suppression when cutting, drilling, or grinding concrete or stone.
  • Fit on-tool dust extraction with an H-class vacuum for dry cutting operations.
  • Wear RPE that has been face-fit tested to your face when required by the COSHH assessment.
  • Use a vacuum with an H-class filter for clean-up — never dry sweep silica dust.
  • Attend health surveillance including lung function testing as required for your exposure.
  • Read the COSHH assessment for your task and follow all specified dust controls.
  • Work outdoors or ensure good ventilation when carrying out dust-generating activities.
  • Check that water suppression and extraction systems are working before starting the task.
  • Report any persistent cough, breathlessness, or chest tightness to your supervisor.
  • Change filters on extraction equipment at the intervals specified by the manufacturer.
  • DON'T cut concrete, stone, or brick without water suppression or dust extraction.
  • DON'T use dry cutting methods when wet cutting equipment is available on site.
  • DON'T work without RPE when the COSHH assessment requires respiratory protection.
  • DON'T sweep silica dust with a broom — use an H-class vacuum or wet methods.
  • DON'T skip health surveillance — lung function testing detects damage before you feel symptoms.
  • DON'T ignore the COSHH assessment — it specifies the controls you must use for each task.
  • DON'T work in enclosed spaces without ventilation when generating silica dust.
  • DON'T start dust-generating work if extraction or suppression systems are not functioning.
  • DON'T dismiss a persistent cough — it could be the first sign of silicosis.
  • DON'T use extraction equipment with blocked or expired filters — it stops working properly.

See also: Construction Dust Awareness | RPE Selection & Face Fit Testing

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