Report questions effectiveness of power tool dust extraction systems

It's better with a vacuum extractor on the grinder but it can still exceed the legal limit of RCS exposure and you need a mask when working high silica content products such as granite, engineered quartz and sandstone, finds the HSE.

A report by the Health & Safety Executive (HSE) has called into question the effectiveness of the dust extraction systems of power tools.

The report, Assessment of dust extraction system solutions on hand-held electric diamond cutters to BS EN 50632, examines levels of respirable crystalline silica (RCS) on three different systems composing of tool, insert and vacuum unit.

System one measured 0.85mg of RCS in a cubic metre (m3) of air, system two 7.65mg/m3 and system three 16.55mg/m3.

RCS is now classed as a carcinogen coming under the Control of Substances Hazardous to Health (COSHH) regulations. The Workplace Exposure Limit (WEL) for RCS is 0.1mg/m3 during an eight hour working day.

Tests were performed at the Health & Safety Laboratory. A diamond cutter made 13.2m long, 40mm deep cuts into concrete slabs following the manufacturers’ operating instructions.

 The report was authored by HSE scientists Dominic Pocock, John Saunders and Adam Clarke. You can see it at It was directed by tool maker Hilti as part of its ongoing dust awareness campaign, further information on which can be found at