COSHH

Control of Substances Hazardous to Health Regulations 2002

The regulations requiring employers to assess and control exposure to hazardous substances: dusts, fumes, chemicals, biological agents, and anything with a hazard label.

COSHH covers substances that can harm health: chemicals with a hazard classification, dusts in quantity (including silica and wood dust), fumes (welding, diesel exhaust), vapours, mists, gases, biological agents and asbestos-adjacent nasties (asbestos itself and lead have their own regulations). For each, the employer assesses the risk, prevents exposure where reasonably practicable, and otherwise controls it adequately, following the principles of good practice: design and operate processes to minimise emission, take account of all routes of exposure, choose controls proportionate to the risk, prefer measures that control at source, and check and maintain them.

A COSHH assessment for a product starts from its safety data sheet but does not stop there: the sheet describes the substance, the assessment describes your use of it. Who uses it, how much, how often, in what space, with what ventilation, what PPE, what to do when it is spilled or splashed, what health surveillance is needed. Where the hazard is a dust generated by the work (cutting concrete, sanding, chasing), the assessment is of the task, and the control is on-tool extraction and water suppression before it is a mask.

Respirable crystalline silica is the COSHH hazard that construction most underestimates: a workplace exposure limit low enough that a single unprotected day of dry cutting can exceed it, and a disease (silicosis) that arrives twenty years later. The HSE treats dry cutting of concrete, stone and brick without extraction or water as a serious breach.

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