On this page

• What COSHH covers and which substances are in scope
• Key COSHH duties in practice
• What HSE looks for during inspection
• Three actions to take now

The Control of Substances Hazardous to Health Regulations 2002 require employers to prevent or adequately control workers’ exposure to substances that can harm their health.

In theory, most employers know this. In practice, COSHH compliance in many workplaces ranges from thorough to completely absent.

The consequences of getting it wrong can be serious, including occupational asthma, chemical burns, dermatitis, long-term respiratory disease and other work-related ill health.

What counts as a hazardous substance?

COSHH covers more substances than many employers realise.

Hazardous substances can include:

• chemicals and mixtures, such as cleaning products, solvents, paints, lubricants and adhesives;
• dusts, including wood dust, flour dust and respirable crystalline silica;
• fumes generated by welding, cutting, grinding or thermal processes;
• mists, vapours and gases;
• biological agents, including bacteria, moulds and animal allergens;
• substances created by work processes, even where the original product did not appear hazardous.

If a substance is used, generated or stored as part of work and has the potential to harm health through inhalation, skin contact, ingestion or injection, COSHH may apply.

A safety data sheet is a starting point for a COSHH assessment. It is not the assessment itself. Simply keeping SDS files does not demonstrate COSHH compliance.

Key COSHH duties in practice

In practical terms, employers must:

• assess the risk to health from hazardous substances used or created by work activities;
• decide what precautions are needed;
• prevent exposure where reasonably practicable;
• where prevention is not reasonably practicable, adequately control exposure;
• ensure control measures are properly used and maintained;
• monitor exposure where needed to confirm controls are effective;
• provide health surveillance where the assessment shows it is required;
• prepare procedures for accidents, incidents and emergencies involving hazardous substances;
• provide employees with suitable information, instruction, training and supervision.

Most COSHH failures occur because the assessment does not reflect actual use. A proper COSHH assessment should consider how the substance is used, how often it is used, how long exposure lasts, who may be exposed, how exposure could occur and whether the controls are effective.

What HSE looks for during inspection

When inspecting COSHH arrangements, HSE may expect to see:

• current COSHH assessments for hazardous substances used or generated by the work;
• evidence that the assessments reflect actual use, not just SDS information;
• suitable control measures in place;
• evidence that controls are maintained and used correctly;
• Local Exhaust Ventilation examination and test records where LEV is used;
• face-fit testing where tight-fitting respiratory protective equipment is used;
• health surveillance records where required;
• evidence that workers have been trained and understand the risks.

HSE will also look beyond the paperwork. RPE stored in a cupboard but not used, LEV that has not been examined, or workers who cannot explain the substances they use are signs that COSHH is not being properly managed.

Three things to do now

List every hazardous substance used, generated or stored in your workplace and confirm whether a current, task-specific COSHH assessment is in place.

Check whether health surveillance is required, particularly where workers may be exposed to sensitisers such as isocyanates, epoxy resins, wood dust or other substances known to cause occupational disease.

Confirm that any Local Exhaust Ventilation systems have been examined and tested within the required examination period — commonly at least every 14 months for LEV, unless a different interval applies.

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Last reviewed: June 2026