Hilti commissioned HSL, the laboratory of the Health & Safety Executive, to assess the dust extraction systems on three hand-held electric diamond cutters, according to BSEN50632.
Inhalable and respirable dust concentrations were measured in the breathing zone of the operator while they performed a standardised task with one of the tools using the recommended dust control. The task involved using the diamond cutter to make cuts into concrete slabs. Each cut was a minimum of 13.2 metres long and 40mm deep.
The cutters tested were:
• Hilti DCH 300-X saw fitted with a 305mm diameter SP-S 305/22 Univ blade with extraction provided by a Hilti VC 40-UM vacuum unit
• Makita 4112 HS saw fitted with a 300mm diameter Comet Rapide blade with extraction provided by a Makita VC4210M vacuum unit;
• Husqvarna K4000 fitted with a 350mm diameter Vari-cut Electric blade using a Husqvarna S13 vacuum unit.
The Hilti came out on top, producing the least amount of breathable dust. This does not mean it is the best at cutting things – the job it is designed to do – it just means it creates the least dust pollution.
The mean dust concentrations when using the Hilti dust extraction system were 0.85 mg/m3 and 2.45 mg/m3 for respirable and inhalable dust respectively.
The mean dust concentrations when using the Makita dust extraction system were 7.65mg/m3 and 16.55 mg/m3 for respirable and inhalable dust respectively.
The mean dust concentrations when using the Husqvarna dust extraction system were 15.65mg/m3 and 38.90 mg/m3 for respirable and inhalable dust respectively.
The HSE’s Workplace Exposure Limit (WEL) for respirable crystalline silica (RCS) is 0.1mg/m3 across an eight hour working day, which means that the tests found none of the tools tested to be as good as they need to be.
Hilti has made the summary report available at www.hilti.co.uk/content/dam/documents/e1/health-and-safety/HSE_abridged_testing_report_final.pdf