Quick answer: Silica dust is the most significant occupational health risk on UK construction sites, governed by COSHH 2002 and HSE EH40 which sets the respirable crystalline silica (RCS) Workplace Exposure Limit at 0.1 mg/m³ over an 8-hour TWA. On-tool M-Class extraction is the minimum control for most silica-generating tasks; H-Class is required in enclosed environments or where the risk assessment identifies higher exposure. General-purpose vacuums are not rated for RCS and must not be used for silica dust control.
Silica dust is the most significant occupational health risk on UK construction sites. It is produced whenever silica-containing materials — concrete, sandstone, brick, mortar, fibre cement board — are cut, ground, drilled or sanded. The dust particles produced are invisible to the naked eye, which is part of what makes the hazard so consistently underestimated on site.
For site managers, principal contractors and trades operating under CDM 2015, silica dust is a COSHH hazard requiring formal assessment, control hierarchy, and documented compliance. The HSE's Construction Dust guidance and the WEL for respirable crystalline silica set the standard. Enforcement has increased significantly over the last five years, with improvement notices and prosecution following site inspections where dust control is inadequate.
The practical problem on most construction sites is not that contractors are unaware of silica dust — it is that the control measures in place are inadequate for the actual exposure generated. Common failures include:
- Using water suppression alone on high-energy cutting without on-tool extraction
- Operating M-Class or general-purpose vacuums on silica-generating tasks — standard vacuums allow re-emission of fine respirable particles
- RPE provided but not worn, or not face-fit tested
- No documented COSHH assessment for specific dust-generating tasks
- Failing to consider secondary exposure — workers in adjacent areas during cutting operations
The cumulative effect of inadequate control is irreversible. Silicosis has no treatment.
COSHH Regulations 2002 — silica is a substance hazardous to health. Employers must assess the risk, implement a hierarchy of control, and demonstrate exposure is reduced as low as reasonably practicable and below the WEL. The WEL for RCS is 0.1 mg/m³ as an 8-hour TWA. HSE Construction Dust guidance specifies on-tool extraction combined with water suppression as the control for most high-energy operations. CDM 2015 — principal contractors and designers have specific duties to plan and manage dust risk during both design and construction phases.
On-tool dust extraction is the primary engineering control for silica-generating tasks. The vacuum connected to the tool must be rated to the correct filtration standard. M-Class (99.9% at 1 micron) is the minimum for construction silica work; H-Class is required in higher-risk or enclosed environments. The V-TUF MIGHTY HSV is an M-Class wet and dry dust extractor used across construction sites for on-tool extraction during grinding, cutting, drilling and chasing. Water suppression should be used alongside extraction — not as an alternative to it. RPE (FFP3 minimum) is the last line of defence, not the primary control.
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