Stone, Silica and Worktop Fabrication

Engineered stone can contain up to 95% crystalline silica, according to HSE. Natural stone varies: granite and sandstone carry a lot, limestone and marble usually less, so ask your supplier for the silica content of what you cut. The same cut on engineered stone produces far more of the dangerous dust.

HSE EH40

0.1 mg/m³ respirable crystalline silica as an 8-hour time-weighted average.

Water suppression must reach the point of cut through an on-tool feed at the correct flow, running for the whole cut including the start and finish. On-tool extraction must use the shroud designed for that tool and disc size, M class minimum for silica, H class better.

HSE research found dry fabrication typically gives five to ten times higher respirable crystalline silica exposure than wet methods using the same tools. HSE says dry cutting of engineered stone is unacceptable and that water suppression is how the law's control duty is met (COSHH regulation 7).

COSHH regulation 9

Local exhaust ventilation must be thoroughly examined and tested at least every 14 months, and the record kept for at least 5 years.

RPE is the last line of control, used for the residual exposure after water, extraction and enclosure have done their work. Every wearer of tight-fitting RPE must be face-fit tested for the specific make, model and size, and retested if the wearer's face changes significantly or the make or model changes. Facial hair at the seal defeats the mask, so a worker who will not be clean shaven needs a powered hood or visor instead.

COSHH regulation 11

Health surveillance is needed where workers are regularly exposed and silicosis or COPD may develop. The pack covers a baseline and periodic respiratory questionnaire and spirometry, with chest imaging where indicated and an exit assessment. Each worker's health record must be kept for at least 40 years from the last entry.

HSE is making more than 1,000 inspection visits to fabricators across Great Britain through 2026/27. Four businesses have already been ordered to stop working with engineered stone after failing inspection, because they had too few controls to keep workers safe from silica dust.