COSHH assessment for construction: a step-by-step guide
Dust, cement, solvents and resins cause more ill health in construction than accidents cause injuries. A COSHH assessment is how you identify those substances and control exposure. Here is how to do one properly.
What is COSHH?
The Control of Substances Hazardous to Health Regulations 2002 (COSHH) require employers to prevent or adequately control exposure to hazardous substances. Regulation 6 requires a suitable and sufficient assessment of the risks before the work starts. Asbestos and lead have their own regulations, but they belong in your health risk planning too.
Substances that matter most on construction sites
| Substance | Where it comes from | Main harm |
|---|---|---|
| Respirable crystalline silica (RCS) | Cutting, chasing, drilling or grinding concrete, brick, block, stone, tiles | Silicosis, lung cancer, COPD |
| Wood dust | Sawing and sanding timber and MDF | Asthma, nasal cancer (hardwood) |
| Cement and wet concrete | Mixing, placing, screeding | Dermatitis, chemical burns |
| Solvents, paints, adhesives | Coatings, sealants, flooring | Dizziness, organ damage, dermatitis |
| Isocyanates | Spray foams and some two-pack paints | Occupational asthma |
| Diesel engine exhaust | Plant and generators in enclosed areas | Lung cancer, respiratory irritation |
How to carry out a COSHH assessment: 7 steps
- List the substances used or produced by the task, including dusts and fumes created by the work, not only products in tins.
- Read the safety data sheets (section 2 hazards, section 8 exposure controls) and check workplace exposure limits in HSE's EH40.
- Decide who could be exposed and how: inhalation, skin contact, ingestion; your workers and others nearby.
- Choose controls in the right order: eliminate or substitute (e.g. pre-cut materials), engineering controls such as on-tool extraction or water suppression, ventilation, then work methods and finally respiratory protective equipment (RPE) and gloves.
- Specify RPE properly: correct protection factor for the dust, face-fit tested for tight-fitting masks.
- Plan monitoring and health surveillance where required, for example for dermatitis or occupational asthma risks.
- Record, brief and review: record the findings, brief the team, and review when the task, product or method changes.
Create COSHH assessments linked to your RAMS. Start free with CDM Creator: answer a few questions about your project and get a site-specific document ready to review and sign on screen.
What to record
- Task, location and substances (product names and dusts or fumes produced).
- Hazards from the safety data sheet and any exposure limits.
- Who is exposed, how often and for how long.
- Control measures, RPE and PPE specified, and how they are checked.
- Storage, spillage, first aid and emergency arrangements.
- Health surveillance needs, review date and sign-off.
Common mistakes
- Filing safety data sheets instead of assessing the task.
- Ignoring dust created by the work itself, which is often the biggest risk.
- Relying on disposable masks as the only control for silica.
- No face-fit testing, no maintenance of extraction equipment.
FAQ
Is a safety data sheet the same as a COSHH assessment?
No. A safety data sheet is information from the supplier about a product. A COSHH assessment looks at how the substance is used on your task and sets the controls for your workers.
Does COSHH cover dust from cutting concrete?
Yes. Respirable crystalline silica created by cutting, drilling or grinding concrete, brick and stone is a substance hazardous to health and must be assessed and controlled.
Do I need to write a COSHH assessment down?
If you employ five or more people you must record the significant findings. In practice principal contractors expect written COSHH assessments with your RAMS.
Is asbestos covered by COSHH?
Asbestos is covered by the Control of Asbestos Regulations 2012 rather than COSHH, but it must still be identified and managed before work starts.
This article is general guidance, not legal advice. Documents must be reviewed by a competent person and reflect the actual site and work. Sources: Control of Substances Hazardous to Health Regulations 2002 (as amended); HSE, EH40 Workplace exposure limits; HSE, COSHH essentials for construction; Control of Asbestos Regulations 2012.