Respirable Crystalline Silica — RCS Dust Extraction & COSHH | V-TUF

Respirable crystalline silica — dust extraction and COSHH compliance for construction

Respirable crystalline silica (RCS) is the most significant occupational health hazard in the UK construction industry. Cutting, grinding, drilling, chasing and breaking work on silica-containing materials — concrete, sandstone, brick, mortar, tiles and engineered stone — generates fine airborne particles that penetrate deep into the lungs and cannot be exhaled. Prolonged exposure causes silicosis, an irreversible and potentially fatal lung disease. RCS also causes lung cancer and is associated with kidney disease and chronic obstructive pulmonary disease (COPD).

This page explains the regulatory framework governing RCS on construction sites, what the Workplace Exposure Limit means in practice, why on-tool extraction is the only reliable control measure, and which V-TUF machines meet the required standard.

The regulatory framework — COSHH and the WEL

Respirable crystalline silica is a hazardous substance under the Control of Substances Hazardous to Health Regulations 2002 (COSHH). Employers and self-employed contractors have a legal duty to prevent or adequately control worker exposure to RCS.

The Workplace Exposure Limit (WEL) for RCS is 0.1 mg/m³ as an 8-hour time-weighted average. This is a very low concentration — invisible to the naked eye and undetectable without monitoring equipment. Research consistently shows that dry cutting, grinding and drilling on silica-containing materials without extraction can generate airborne RCS at concentrations ten to one hundred times the WEL within seconds of starting work.

Under CDM 2015, contractors must ensure that suitable plant and equipment is provided and maintained for the work being carried out. For silica-generating activities, this means on-tool dust extraction rated to the correct classification — not a general workshop vacuum, not a water suppression system alone, and not relying on respiratory protective equipment (RPE) as the primary control. The hierarchy of control under COSHH requires elimination, substitution and engineering controls before RPE. On-tool M-Class or H-Class extraction is the engineering control for RCS.

M-Class vs H-Class for silica

M-Class extraction is the minimum standard for general construction dust including RCS from concrete, brick and mortar cutting and grinding. M-Class extractors filter to 99.9% efficiency at 1 micron — sufficient to capture the respirable fraction of silica dust at source when the extractor is correctly connected to the tool.

H-Class extraction is required where the silica concentration is particularly high — engineered stone (which contains up to 93% silica by weight), flint, chert, and other very high-silica materials. H-Class is also the required standard for any work where the COSHH assessment identifies that M-Class is insufficient based on the duration and intensity of the work. H-Class filters to 99.995% efficiency and uses sealed disposal to prevent secondary exposure during bag change.

Engineered stone specifically: Since January 2024, the HSE has strongly indicated that M-Class alone is insufficient for dry cutting of engineered stone worktops, and H-Class with water suppression is the expected standard. Several enforcement actions have followed dry cutting of engineered stone without adequate controls.

Why on-tool extraction is the only reliable RCS control

Water suppression (wet cutting) reduces airborne RCS significantly but does not eliminate it — and wet cutting is not always practical for all cutting operations, particularly chasing and drilling. Water suppression combined with on-tool M-Class or H-Class extraction is the gold standard for high-intensity silica-generating work.

General ventilation — opening windows, running fans — dilutes airborne dust but does not capture it at source and does not reliably maintain exposure below the WEL in enclosed spaces. HSE guidance is explicit that general ventilation is not an adequate control for RCS.

Respiratory protective equipment (RPE) — FFP3 masks, powered air-purifying respirators (PAPRs) — protects the wearer but does nothing for other workers in the same space and does not prevent surface contamination that creates secondary exposure. RPE is a last resort, not a substitute for engineering control.

On-tool extraction captures RCS at the point of generation, before it becomes airborne, before it spreads through the workspace, and before anyone breathes it. It is the only control measure that reliably maintains RCS exposure below the WEL for the operative and others nearby.

V-TUF machines for RCS extraction — M-Class

For general construction work generating RCS — concrete cutting and grinding, brick and block work, tile cutting, mortar raking, wall chasing, core drilling — the V-TUF MIGHTY HSV range is the standard M-Class specification. On-tool power take-off connects the extractor directly to the tool, capturing dust the instant it is generated.

V-TUF MIGHTY HSV — 21L M-Class, 110V and 240V

M-Class dust extraction with automatic filter cleaning for sustained on-tool use. 110V site voltage and 240V. Available as standalone machine or as Kit 1 (starter accessory kit) and Kit 2 (extended accessory kit). SKU MIGHTYHSV110 / MIGHTYHSV240 from £449.99. View MIGHTY HSV →

V-TUF MIGHTY XL HSV — 37L M-Class, 110V and 240V

Larger capacity M-Class extractor for higher-throughput site work and longer working periods between filter services. SKU MIGHTYXLHSV110 / MIGHTYXLHSV240, £449.99. View MIGHTY XL HSV →

V-TUF machines for RCS extraction — H-Class

For engineered stone, flint, high-silica aggregates, and any work where the COSHH assessment requires H-Class, V-TUF specifies the MIDI HSV and MAXi range. Both use ULPA15 sealed filtration with certified disposal bags — the combination required to achieve H-Class certification and provide an auditable disposal record.

V-TUF MIDI HSV — 21L H-Class, 110V and 240V

Compact H-Class extraction for trades working with engineered stone, high-silica materials and other Category 1 COSHH dusts. Van-friendly, site-ready. SKU MIDIHSV110 / MIDIHSV240, £899.99. View MIDI HSV →

V-TUF MAXi — 50L and 80L H-Class, 110V and 240V

High-capacity H-Class extraction for sustained high-output silica-generating work and larger project sites. 50L and 80L capacity options. From £799.99. View MAXi →

RAMS, pre-start documentation and silica

Under CDM 2015, contractors must produce a project-specific Risk Assessment and Method Statement (RAMS) for each work activity. Where the activity generates RCS, the RAMS must specify the extraction method and classification being used. Naming the V-TUF MIGHTY HSV (M-Class) or MIDI HSV / MAXi (H-Class) by model in the RAMS and pre-start pack gives the Principal Contractor an auditable answer for their CDM compliance records.

HSE inspectors checking site compliance for silica control will ask to see the RAMS and will check that the extraction equipment on site matches what the RAMS specifies. Generic RAMS that name only ‘M-Class extraction’ without specifying the machine are not best practice — naming the machine removes ambiguity and demonstrates that the contractor has made a deliberate, informed equipment choice.

View the full construction and CDM 2015 hub →   View the HSE and COSHH compliance centre →

Trade accounts

V-TUF operates trade and contractor account terms for construction contractors, trades businesses and the principal contractors specifying extraction equipment for their sites. UK warehouse, UK technical support, spares held for every machine in current production.

Telephone: 01522 787978. Email through the contact page.