Guide
Manage hazardous construction materials
How to comply with COSHH 2002 when working with cement, silica dust, solvents, lead paint, and wood dust on construction sites. Covers COSHH assessments, workplace exposure limits, health surveillance, RPE selection, and dust suppression controls.
When this applies
You must manage hazardous construction materials if your workers are exposed to substances that can cause ill health on site. This includes activities such as:
- Cutting, grinding, or drilling concrete, brick, stone, or engineered stone (silica dust)
- Mixing, laying, or finishing cement, mortar, or concrete (cement dermatitis and burns)
- Sanding, sawing, or routing timber (wood dust)
- Using paints, adhesives, sealants, or cleaning agents (solvents and isocyanates)
- Disturbing or removing old lead-based paint during refurbishment
The Control of Substances Hazardous to Health Regulations 2002 (COSHH) place a legal duty on employers to assess and control exposure to these substances. Silica dust control is a top HSE enforcement priority for 2025/26, with inspectors actively checking COSHH assessments and dust controls on construction sites.
How to comply
Follow these steps to meet your COSHH duties for hazardous materials on construction sites.
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1. Identify hazardous substances on your site
List every substance your workers use or create on site. Check product labels and obtain Safety Data Sheets (SDS) from suppliers. Include process-generated substances such as silica dust from cutting concrete, wood dust from sawing timber, and welding fumes. Do not overlook cleaning products, release agents, and adhesives.
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2. Complete a COSHH assessment for each substance
For each hazardous substance, record who is exposed, how they are exposed (inhalation, skin contact, ingestion), how often and for how long, and what controls are needed. Use the manufacturer's Safety Data Sheet and HSE COSHH Essentials guidance sheets. Review and update assessments when work activities change.
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3. Apply the hierarchy of controls
Prioritise controls in this order: eliminate the substance entirely; substitute with a less hazardous alternative (for example, water-based coatings instead of solvent-based); use engineering controls such as wet cutting, water suppression, or on-tool local exhaust ventilation (LEV); implement procedural controls such as limiting exposure time; provide RPE and PPE only as a last resort.
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4. Select and provide appropriate RPE
Where engineering controls alone cannot reduce exposure below workplace exposure limits, provide respiratory protective equipment (RPE). FFP3 disposable respirators are the minimum for silica and hardwood dust. Powered air-purifying respirators give higher protection for prolonged or heavy-dust tasks. All tight-fitting RPE must be face-fit tested for each individual worker under COSHH Regulation 7.
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5. Set up health surveillance
Arrange health surveillance through an occupational health provider for workers regularly exposed to silica dust, cement, hardwood dust, or other substances where COSHH assessment identifies a risk of occupational disease. Health surveillance typically includes baseline and periodic lung function testing and skin checks. Keep health surveillance records for 40 years.
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6. Train your workforce
Before work starts, train all workers on the hazardous substances they will encounter, the health risks, how to use controls and PPE correctly, emergency procedures for spills or overexposure, and how to report symptoms. Refresh training when substances or methods change.
Silica dust: workplace exposure limit and controls
Respirable crystalline silica (RCS) is generated whenever concrete, sandstone, brick, mortar, or engineered stone is cut, ground, drilled, or demolished. Inhaling silica dust causes silicosis, chronic obstructive pulmonary disease (COPD), and lung cancer. There is no known safe level of exposure.
You must keep exposure as low as reasonably practicable and always below the workplace exposure limit.
Dust suppression methods for silica
These are the most effective engineering controls for construction sites:
- Wet cutting: Attach a water supply to disc cutters, wall chasers, and core drills. Water suppression can reduce dust by over 90%.
- On-tool extraction: Fit local exhaust ventilation (LEV) to power tools. Ensure the extraction unit has an H-class (HEPA) filter.
- Enclosed cutting areas: Where practicable, cut materials in a segregated area away from other workers.
- Damping down: Wet surfaces before demolition or breaking out. Avoid dry sweeping of dust; use an H-class vacuum or damped-down methods instead.
Cement: dermatitis prevention
Wet cement is strongly alkaline (pH 12-13) and contains traces of chromium VI, which causes allergic contact dermatitis. Once a worker becomes sensitised to chromium VI, the allergy is permanent and they may be unable to continue working with cement.
Preventing skin contact is essential. The following snippet sets out the regulatory limits and required control measures.
PPE requirements on construction sites
PPE is a last resort under the hierarchy of controls, but construction sites almost always require baseline PPE. When working with hazardous substances, you must ensure workers have the correct equipment for the specific risk, not just standard site PPE.
Common problems
- Workers not using RPE: Check that RPE has been face-fit tested and is comfortable. Poorly fitting masks encourage removal. Consider powered respirators for extended tasks.
- Wet cutting not practical on site: Use on-tool extraction with an H-class vacuum as an alternative. Where neither is possible, segregate the work and restrict access to the immediate area.
- No Safety Data Sheets available: Contact your supplier directly. Under REACH, suppliers must provide an SDS for any substance classified as hazardous. Do not use a substance without an SDS.
- Worker reports skin irritation: Remove them from cement or solvent contact immediately. Refer them for occupational health assessment. Record the incident and review your COSHH assessment. Confirmed occupational dermatitis is reportable under RIDDOR.
- HSE inspector asks for COSHH assessments: You must be able to produce written COSHH assessments for every hazardous substance on site. Keep them accessible in the site office alongside Safety Data Sheets.
What to do next
- Review your COSHH assessments at least annually, or whenever work methods, substances, or site conditions change
- Ensure LEV equipment is examined and tested at least every 14 months by a competent person
- If workers handle asbestos-containing materials, separate regulations apply — see the Control of Asbestos Regulations 2012
- For construction product marking and compliance (CE/UKCA), see our guide on construction product marking compliance
- For a quick compliance check across all construction materials obligations, see the construction materials compliance checklist