Drilling into concrete, masonry, block and stone generates respirable crystalline silica (RCS) at concentrations that can exceed the Workplace Exposure Limit of 0.1 mg/m³ within seconds of starting work. Core drilling, percussion drilling, hammer drilling and diamond drilling all create fine silica dust - the particle size generated by drilling penetrates deepest into the lungs and is the most hazardous fraction to capture. This article explains the COSHH requirements for dust-free drilling, how the control hierarchy applies, and which V-TUF equipment meets the required standard.
The regulatory position
Drilling that generates RCS is a COSHH-controlled activity under the Control of Substances Hazardous to Health Regulations 2002. The WEL for respirable crystalline silica is 0.1 mg/m³ as an 8-hour time-weighted average - one of the lowest WELs in EH40. Uncontrolled drilling through concrete or masonry can generate RCS concentrations significantly above this limit in the immediate breathing zone of the operative within moments of starting.
Under CDM 2015, contractors must plan dust control for drilling operations as part of the Pre-Construction Health and Safety Plan. Method statements must specify the control measures - including the extraction class - for every drilling activity that generates hazardous dust. Principal contractors are increasingly requiring operatives to name the specific machine, not just the classification.
The COSHH hierarchy for RCS requires engineering controls before RPE. On-tool extraction is the engineering control for drilling. RPE - FFP3 masks - is a supplementary control, not a substitute. Where RPE is used, COSHH Regulation 7 requires face-fit testing for each individual wearer.
The control hierarchy for drilling dust
On-tool extraction - the primary control
On-tool dust extraction captures RCS at the point of generation - the drill bit or core - before it becomes airborne and enters the breathing zone. For drilling operations, on-tool extraction requires a shroud or dust cup attached directly to the drill, connected via hose to a certified M-Class or H-Class extractor. The extractor must run throughout the drilling operation - dust is generated from the first rotation of the drill bit, not just during breakthrough.
For percussion and hammer drilling into concrete and masonry, M-Class extraction is the minimum standard. For core drilling - which generates a higher volume of fine silica dust over longer periods - H-Class extraction is the more appropriate specification where the COSHH risk assessment confirms significant exposure risk.
Water suppression - for core drilling
Wet core drilling with a continuous water feed suppresses RCS generation at source, reducing airborne dust by 80–95% during the cutting operation. Water suppression is not an alternative to on-tool extraction - wet core drilling produces silica-laden slurry that must be removed before it dries and returns to respirable dust form. Slurry clean-up must use wet methods or an H-Class vacuum. Dry sweeping dried slurry is prohibited under COSHH. The water feed must be continuous throughout the core drilling operation - intermittent water does not achieve the suppression effect.
Drill shrouds and dust cups
A drill shroud (also called a dust cup or dust pod) fits around the drill bit and creates a sealed collection point that connects directly to the extractor hose. Without a shroud, even a correctly specified M-Class or H-Class extractor cannot capture drill dust effectively - holding the extractor hose near the drill face is not sufficient. The shroud is not optional; it is the component that makes on-tool extraction function as a COSHH control.
V-TUF supplies the Drill Pod shroud (VTM208) for 20mm core drill operations - a purpose-built dust shroud that connects directly to the RUCKVAC or MINI HSV extraction hose. For larger core diameters and percussion drilling, shroud selection should match the drill manufacturer's accessory specification.
LEV - the 14-month examination requirement
The dust extractor used for on-tool drilling extraction is classified as local exhaust ventilation (LEV) under COSHH Regulation 9. LEV equipment must be examined and tested at least every 14 months and records kept for five years. If the extractor fails examination, work that generates the controlled dust must stop until the machine is repaired and re-examined. This applies to both corded and cordless extractors used as on-tool LEV.
Which extractor for drilling - M-Class or H-Class?
M-Class - general concrete, brick, block and masonry drilling
M-Class extraction is the minimum standard for percussion and hammer drilling into most construction materials - concrete, brick, block, mortar and sand-lime stone. The V-TUF RUCKVAC-ION (cordless, 300W brushless, H13 HEPA) is the preferred specification for drilling operations where cable management is impractical. The V-TUF MINI HSV or MIGHTY HSV are the corded alternatives for 110V site supply.
V-TUF RUCKVAC-ION — cordless M-Class →
V-TUF MINI HSV — M-Class, 110V →
V-TUF MIGHTY HSV — M-Class, 21L →
H-Class - engineered stone, high-silica materials and pre-2000 buildings
H-Class extraction is required for drilling into engineered stone (up to 93% silica), flint, chert and other very high-silica materials. In pre-2000 buildings where asbestos status has not been confirmed by a full survey, H-Class should be the default for any drilling that penetrates existing fabric - asbestos fibres can be encountered in textured coatings, fire protection, pipe lagging and composite materials during drilling work. H-Class is mandatory for all asbestos vacuum work under CAR 2012.
V-TUF MIDI HSV — H-Class, 110V →
V-TUF Drill Pod - VTM208
The V-TUF Drill Pod is a 20mm core drill dust shroud that connects directly to the RUCKVAC and MINI HSV extraction hose, creating a sealed dust collection point at the drill bit. Using the Drill Pod with an M-Class or H-Class extractor is the correct on-tool extraction setup for 20mm core drilling.
V-TUF Drill Pod — 20mm core drill shroud (VTM208) →
Clean-up after drilling
Drill dust that settles on surfaces - floor, sill, work platform - must be cleaned up using an M-Class or H-Class vacuum. Dry sweeping re-suspends settled RCS and is prohibited under COSHH. Compressed air blowing to clear surfaces is also prohibited. The H-Class vacuum or wet methods are the only compliant clean-up approaches for silica-contaminated surfaces. Where wet core drilling was used, slurry must be vacuumed up before it dries - dried slurry must never be dry-swept.
RAMS documentation for drilling
A compliant RAMS for drilling on a silica-generating material should specify the drill type, the material being drilled, the shroud being used, the extractor model and classification (M-Class or H-Class), and whether the extractor is corded or cordless. It should confirm that LEV examination records are current. Principal contractors are increasingly checking these details on site - naming the RUCKVAC-ION or MIDI HSV by model removes ambiguity from the method statement and demonstrates a deliberate, informed equipment choice.
Related guidance
Respirable crystalline silica — the complete COSHH control guide →
Cordless and battery dust extraction — M-Class without a mains supply →
M-Class dust extraction explained →
H-Class dust extraction explained →
Concrete cutting and grinding on live sites →
M-Class or H-Class: why it depends on what the building is made of →
