If people at work use or are exposed to substances that could harm their health, the Control of Substances Hazardous to Health Regulations 2002 (COSHH) apply to you. That covers far more than chemical plants: cleaning products, paints, adhesives, fuels, wood and silica dust, welding fume and biological agents all count.
What COSHH requires
In short, an employer must:
- Find out which hazardous substances are used or created at work.
- Assess the risk to health from each, and decide how to prevent or adequately control exposure.
- Put the controls in place, maintain them and make sure they are used.
- Monitor exposure and provide health surveillance where needed.
- Plan for accidents and emergencies.
- Inform, instruct and train employees, and supervise them.
If you have five or more employees, you must record the significant findings of your assessments. Exposure must stay below any workplace exposure limits published in the HSE document EH40.
Start with a COSHH register
A register is the list of every hazardous substance on site. It is the backbone of COSHH compliance, because you cannot assess what you have not listed. For each substance, record:
- The product name and supplier.
- Where it is used and stored, and roughly how much.
- Its hazard classification and pictograms, from section 2 of the safety data sheet (SDS).
- The date of the current safety data sheet, which suppliers must provide.
- Whether a COSHH assessment exists, and when it is due for review.
Walk the site rather than relying on purchase records: substances created by the work, such as dust or fume, never appear on an invoice.
The five steps of a COSHH assessment
- Identify the hazard: read the safety data sheet, and consider substances produced by the task.
- Decide who might be harmed and how: by breathing it in, skin contact, swallowing or splashes to the eyes, and how often and for how long.
- Evaluate the risk and decide on controls, following the hierarchy: eliminate or substitute the substance first, then engineering controls such as local exhaust ventilation, then safe systems of work, and personal protective equipment last.
- Record the significant findings, including the controls and PPE, storage, first aid and spill response.
- Review the assessment and update it when things change.
How often should COSHH assessments be reviewed?
The regulations require a review whenever there is reason to think the assessment is no longer valid, such as a new process, a changed product or safety data sheet, an incident, or health surveillance results. Many businesses also set a fixed review date, often annually, so nothing goes stale.
Local exhaust ventilation must be thoroughly examined and tested at least every 14 months under COSHH.
Frequently asked questions
Is a safety data sheet a COSHH assessment?
No. The safety data sheet tells you about the substance. The COSHH assessment is about how your people use it, in your workplace, and the controls you have chosen.
Do I need a COSHH assessment for every cleaning product?
You need to assess the risk from each hazardous substance, but products used in the same way can share one assessment. Products used exactly as a householder would, in small quantities, may need only a simple assessment.
Who can carry out a COSHH assessment?
A competent person: someone with enough knowledge of the work and the substances. In a small business that is often a manager or supervisor, with help from the safety data sheet and HSE guidance.
This guide is general information for UK businesses, not legal advice. Check the current regulations and HSE guidance at hse.gov.uk, and take professional advice for your situation.