The Extractor Is Part of the Tool: Specifying On-Tool Dust Control for a UK Stone Shop

Walk into plenty of UK stone shops and you will see a £400 grinder paired with a wheezing wet-and-dry vac that was bought for a DIY project. That is backwards. In stone fabrication, the extractor is not a tidy-up accessory; it is part of the cutting system. If it is underspecified, leaking or clogged, the tool throws respirable crystalline silica into the air, the operator breathes it, and the shop slowly becomes a health and legal problem.

Start with the dust, not the machine

Stone dust is not just a nuisance that settles on the kettle. Cutting sandstone, concrete, quartz and engineered stone can release respirable crystalline silica, and that is the bit that matters. Under COSHH, you are expected to control exposure, keep controls in good order and prove you are doing it. Water suppression and on-tool extraction are the practical engineering controls for most stone work. A broom and a cheap fan are not.

On-tool extraction captures dust at the shroud, before it becomes background dust. That means the shroud has to fit the tool properly, the hose has to be the right size, and the extractor has to pull enough air through the system while the tool is under load. A unit that sounds impressive in an empty workshop can fall flat when a 230 mm grinder is buried in a worktop.

Filter class is a floor, not a badge

Filter classes under EN 60335-2-69 are often sold as a simple ladder: L, M, H. For typical stone fabrication, M-class is the sensible minimum to specify. H-class is not a default upgrade for every stone shop; it is for higher-risk dusts and specific situations. Read your risk assessment and current HSE guidance rather than letting a catalogue sell you the most expensive box on the page.

The class matters, but so does the filter area, the bag system and the way the unit cleans itself. A small M-class extractor with a tiny filter will clog quickly and lose suction. A larger unit with automatic filter cleaning may cost more upfront but keep working through a full day of cutting. Ask for airflow figures at the tool, not just tank litres. Tank size tells you how long you can work before emptying; it tells you nothing about capture.

Real airflow beats catalogue numbers

Airflow is the whole game. Long hoses, narrow ports, sharp bends and clogged filters all steal performance. Keep the hose as short as you can practically manage, avoid unnecessary reducers, and check that the shroud seals around the blade or bit. A 35 mm hose is common on stone tools, but some grinders and routers want 32 mm, and larger cutting heads may need 38 mm. Do not force a big hose through a tiny adapter and expect the extractor to compensate.

Use a dedicated hose per tool if you can. Swapping one hose between a grinder, a router and a core drill is how you lose adapters, split cuffs and waste time. Quick-release fittings are worth the modest cost. So is a spare hose.

Water feed is not a backup

For core drilling and many stone routing jobs, water feed is a primary control, not a decorative dribble. Check the water pressure, the flow rate, the nozzle condition and the route of the hose. Hard water will scale up nozzles and fittings, especially in older UK workshops. If the water feed is intermittent, the dust control is intermittent too.

Water and slurry bring their own mess. Plan where the slurry goes, use settling trays or bunds where needed, and do not let it dry into a fine dust that gets swept back into the air. Wet cutting and on-tool extraction are not enemies; they are two parts of a sensible control plan.

The maintenance habits that keep LEV working

A daily five-minute check beats an annual panic. Look at the hose for splits, check the shroud for cracks, confirm the bag is not overfull, and listen to the extractor. If suction has dropped, investigate before the filter is packed solid. Use the correct bags and filters; bin liners and makeshift seals are false economy.

Clean filters according to the manufacturer's instructions. M-class filters are not designed to be beaten against a wall. Check gaskets and seals, and store the extractor indoors where damp cannot ruin the filter. In the UK, a cold van and a damp workshop are excellent at turning a good filter into a soggy brick.

COSHH also expects LEV to be thoroughly examined and tested by a competent person at least every 14 months, and more often where conditions are harsh. Keep the logbook with the extractor. If you cannot find the test date, assume it is overdue.

A sensible UK shop specification

For a working stone shop, look for an M-class extractor with automatic filter cleaning, a realistic hose length, a tool-triggered start if it suits your setup, and a shroud that actually fits your grinder or router. Add a pre-separator for dry dust if you generate a lot of it, spare filters and bags, and a water feed kit with a pressure regulator for core drilling. Check whether you need 110V for site work or 230V for the workshop, and do not overload a transformer with a unit that draws more than you expected.

Then budget for the boring bits: spare cuffs, hose clips, gaskets and a written maintenance routine. The extractor is part of the tool. If it is wheezing, leaking or clogged, the grinder is not under control.