On-Tool Dust Extraction for UK Trades 2026 — Controlling Construction Dust at Source

Why Dust Control Is a Legal Duty

The Control of Substances Hazardous to Health Regulations (COSHH) require every employer — and that includes sole traders and small firms — to prevent or adequately control exposure to hazardous substances. Construction dust is explicitly covered. RCS has a workplace exposure limit, and the practical reality is that a few minutes of uncontrolled dry cutting can blow you well past that limit for the whole shift.

COSHH does not simply ask you to hand out masks. It asks you to assess the risk, then control it as far up the hierarchy as is reasonably practicable. The HSE expects to see dust being controlled at source — captured or suppressed before it reaches the air you breathe — not just filtered out of your lungs by a mask after the fact. A COSHH assessment that says "wear a mask" and nothing else will not satisfy an HSE inspector, and it will not protect your workers.

The Hierarchy of Control

COSHH is built around a hierarchy of control. You work down it in order, applying the highest-level measure that is reasonably practicable for the task, and only relying on the lower levels once you've done everything sensible above. For construction dust the hierarchy looks like this.

• Eliminate or reduce the task. Can you avoid creating the dust at all? Order materials cut to size, buy pre-cut kerbs and blocks, use a block splitter instead of a cut-off saw, or design out unnecessary chasing. No dust is the only perfect control.
• Water suppression. Where you must cut, feeding a steady supply of water to the blade or bit keeps the dust damp so it cannot become airborne. This is highly effective for cut-off saws and floor saws.
• On-tool extraction (LEV). A shroud or hood on the tool captures dust at the point it is created and draws it into a class-rated dust extractor. This is local exhaust ventilation applied directly at the tool.
• Respiratory protective equipment (RPE). A correctly specified, face-fitted mask is the last line of defence, used to control any residual dust that the measures above have not captured — never as a substitute for them.

The order matters legally as well as practically. If an inspector finds you relying on RPE alone when on-tool extraction or water suppression was reasonably practicable, that is a failure to control at source — regardless of how good the mask is.

M-Class vs H-Class Extractors

Not every vacuum is a dust extractor, and not every dust extractor is suitable for hazardous dust. A standard workshop wet-and-dry vac (often unrated, or L-class) is not adequate for silica or fine wood dust — its filter lets the dangerous fine fraction straight back into the air. For construction dust you need an M-class or H-class extractor, and the class refers to the filtration efficiency and the dust types it is approved for.

*Licensed and non-licensed asbestos work has its own strict regime — an H-class vac is part of it, but asbestos work is never a simple on-tool extraction job and must follow the specific asbestos rules.

For the vast majority of UK trades — bricklayers, groundworkers, kitchen fitters, dry liners, joiners — an M-class extractor is the right default and will satisfy COSHH for silica and wood dust. Step up to H-class where the material or process produces an especially hazardous or carcinogenic dust, or where a method statement or material safety data sheet calls for it. Both classes have an integrated airflow alarm that warns you when flow drops too low to capture dust effectively — if it sounds, stop and find out why before carrying on.

Matching Extraction to the Tool

On-tool extraction only works if the shroud, the hose and the extractor are all matched to the tool and the task. A grinder shroud bolted onto an underpowered vac will not pull enough air to capture grinding dust, and a fine-dust sander connected to a coarse-dust setup will clog in minutes. Here is how the main tools pair with control methods.

The pattern is consistent: for sawing tasks, water suppression is usually the strongest and simplest control; for grinding, chasing, sanding and drilling, a tool-mounted shroud feeding a class-rated extractor is the standard approach. Whichever you use, the control has to be in place from the first cut — switching the extractor on halfway through, or topping up the water once the dust is already flying, defeats the point.

Water Suppression Day to Day

Water suppression is the most under-used control on UK sites, largely because operatives find it messy. But for cut-off saws and floor saws it is highly effective and often the most practicable option. The principle is simple: a continuous, adequate flow of water to the cutting point keeps the dust wet so it falls as slurry rather than rising as airborne RCS.

• Use a proper pressurised water bottle or mains feed — a hand-held trickle is not enough flow to suppress the dust.
• Make sure water reaches the blade from the start of the cut, not after dust has already been generated.
• Manage the slurry. Wet cutting creates runoff that must not enter drains or watercourses untreated.
• Watch for the trade-off with electrical tools — water and 110V kit need sensible handling and RCD protection.

Where water genuinely cannot be used — indoors on finished floors, or near live electrics — fall back to on-tool extraction with an M-class extractor. The two controls solve the same problem in different conditions, and most well-equipped trades carry the means to do both.

Maintenance, Filter Cleaning and Checks

An extractor that is not maintained stops protecting you, often without any obvious sign. Filters blind over with fine dust, airflow drops, and capture efficiency falls away. Build the following into your routine.

• Use the filter-clean function. Most M-class and H-class units have a manual or automatic filter-shaking system. Use it regularly through the day, not just when the airflow alarm sounds.
• Check the airflow alarm works. The low-flow warning is a safety device. Test it and never tape over or ignore it.
• Inspect hoses, shrouds and seals. A split hose, a cracked shroud or a poorly seating filter all leak dust and kill capture. Replace worn parts.
• Change bags before they are full. An overfull bag chokes airflow. Empty and dispose of collected dust safely without releasing it back into the air.
• Keep records. Note checks and filter changes. Good records support your COSHH assessment and demonstrate control if the HSE asks.

None of this replaces the separate statutory thorough examination and test that fixed and certain LEV systems require — that is a distinct legal obligation with its own interval. The day-to-day checks here are about keeping your on-tool extraction working between those formal examinations.

RPE and Face-Fit — the Last Line

Even with good extraction or water suppression, some residual dust usually remains, so RPE is still part of the control package for most cutting and grinding work. The key word is "residual" — RPE controls what is left after the higher controls have done their job, never the whole exposure on its own.

• Specify the right protection factor. For RCS, a disposable FFP3 or a powered/half-mask to an equivalent standard is typically the minimum. Check it against your assessed exposure.
• Face-fit testing is mandatory for tight-fitting masks. A mask only protects if it seals to the individual's face. Each tight-fitting RPE wearer must pass a face-fit test for the specific make and model.
• Clean-shaven for tight-fitting masks. Stubble breaks the seal. Beards mean a loose-fitting powered hood instead.
• Store, inspect and replace. Keep masks clean and undamaged; replace disposables as specified.

The HSE is clear that handing out FFP3 masks instead of providing extraction is not adequate control. RPE complements the engineering controls; it does not replace them.

What the HSE Expects to See

If an HSE inspector visits your site, dust is one of the things they look at closely. They are not looking for a single magic product — they are looking for evidence that you have worked through the hierarchy of control and are managing dust at source. In practice that means:

• A COSHH assessment that names the dust hazards for your actual tasks and sets out the controls.
• Water suppression or on-tool extraction in use on dust-generating tools — not dry cutting with a mask alone.
• M-class or H-class extractors appropriate to the dust, in working order, with their alarms functioning.
• Face-fit records for everyone using tight-fitting RPE, and the right grade of mask for the job.
• Maintenance and checks being done, with enough records to show the controls are kept effective.

Getting this right is not only about avoiding enforcement. The workers most harmed by construction dust are the trades themselves — the people on the tools every day. Controlling dust at source is the single most effective thing you can do to protect your own long-term health and that of your team.

Quick Reference: Dust Control Essentials