What COSHH is
COSHH stands for the Control of Substances Hazardous to Health Regulations 2002. The regulations require employers to control their workers' exposure to substances that can cause ill health. That covers dusts, fumes, gases and vapours that people breathe in. COSHH also covers liquids, gels and powders that reach the skin or eyes, and harmful micro-organisms. Lead, asbestos and radioactive substances have their own regulations, so COSHH does not apply to them.
Source: HSE, COSHH basics
What a COSHH assessment covers
An employer must not start work that could expose employees to a hazardous substance until a suitable and sufficient assessment is done. The assessment looks at the hazards of each substance and the information from its supplier. It considers how much exposure there is, of what kind and for how long. The assessment also takes in the workplace exposure limit, the effect of the controls, and any monitoring or health surveillance results. Hazards are not only found in labelled products. Cutting, sanding and welding create dust and fume, and those count too.
Sources: COSHH Regulations 2002, regulation 6; HSE, How to carry out a COSHH risk assessment
The five steps of a COSHH assessment
HSE sets out five steps for a COSHH assessment.
- Identify the hazards. Check the label and the Safety Data Sheet for each product. Include the dust, fume and vapour that the work itself creates, such as silica dust from cutting.
- Assess the risks. Decide who could be harmed and how: by breathing the substance in, by skin contact or by swallowing it. Think about how often and for how long people are exposed. Include other trades, visitors and members of the public.
- Control the risks. Prevent exposure where you can. Where you cannot, control exposure by working down the hierarchy of control, with PPE last.
- Record your findings. If you have five or more employees, you must record the significant findings. With fewer, HSE says it still makes sense to write down what you have done.
- Review your controls. Check that the controls work. Review the assessment regularly, and again when the substance, the process, the equipment or the people change, or after an accident or near miss.
The role of the Safety Data Sheet
A supplier must give you an up-to-date Safety Data Sheet (SDS) for a product that is dangerous for supply. The SDS sets out the product's hazards, how to handle and store the product, and what to do in an emergency. HSE suggests reading sections 2 and 16 for the hazards, and sections 4 to 8 for emergencies, storage and handling. A Safety Data Sheet is not a risk assessment. You use the information on the SDS to write your own COSHH assessment for the way you use the product.
Sources: HSE, Safety data sheets; HSE, A brief guide to COSHH (INDG136)
Workplace exposure limits (EH40)
A workplace exposure limit (WEL) caps the concentration of a substance in the air a worker breathes, averaged over a set period. HSE publishes the limits in EH40/2005, and the list is legally binding under COSHH. Only about 500 substances have a WEL. Good control keeps exposure below the limit. For substances that can cause cancer, asthma or genetic damage, exposure must be reduced as low as is reasonably practicable.
Sources: HSE, Workplace exposure limits; HSE, EH40/2005 Workplace exposure limits
Controlling exposure: the hierarchy of control
COSHH puts prevention first. Ask whether you need the substance at all, or whether a safer product or form would do, such as a paste instead of a powder. If exposure cannot be prevented, control it at source by changing the process, enclosing it or extracting the dust and fume where they are made. Then keep as few people exposed as possible, and use safe systems of work, storage and cleaning. PPE such as gloves and respirators comes last because PPE is less reliable. Respirators need face fitting and training. Local exhaust ventilation needs a thorough examination and test at least every 14 months.
Sources: HSE, How to carry out a COSHH risk assessment; HSE, A brief guide to COSHH (INDG136)
Health surveillance and monitoring
COSHH requires health surveillance when a substance is linked to a disease such as asthma, dermatitis or cancer, the work makes that disease likely, and there is a valid way to detect it. Typical checks look at lung function or skin condition. The employer keeps a health record for each employee under surveillance, for at least 40 years from the last entry. Air monitoring shows whether exposure stays below the WEL and whether the controls are working.
Sources: HSE, Health surveillance; COSHH Regulations 2002, regulation 11; HSE, Exposure monitoring
Spills, first aid and emergencies
Plan for the accidents and spills you can foresee, and practise the plan. Keep spill equipment, protective equipment and decontamination products ready. Set out what to do for a casualty, and train the people who will act. Plan how the emergency services will get the information they need, and make sure everyone knows the plan.
COSHH assessment template
Fill in one table for each hazardous substance, or for each task that creates one, such as cutting concrete. Copy the table into Word or a spreadsheet, then complete the second column from the Safety Data Sheet and your own site.
| Field | What to record |
|---|---|
| Substance or product | The product name as it appears on the label, or the substance the task creates, such as silica dust. |
| Supplier | The name and contact details of the manufacturer or supplier. |
| SDS reference | The version and date of the Safety Data Sheet you used. |
| Hazard statements | The hazard statements from section 2 of the SDS, such as H317: May cause an allergic skin reaction. |
| Workplace exposure limit | The WEL from EH40/2005 or section 8 of the SDS, if the substance has one. |
| Task | What the work is and how the substance is used, for example mixing, spraying or cutting. |
| Route of exposure | Breathing in, skin or eye contact, swallowing, or skin puncture. |
| Who is exposed | Who could be exposed, how often and for how long. Include other trades, visitors and the public. |
| Control measures | The controls in hierarchy order, starting with elimination or a safer substitute. |
| PPE and RPE | The gloves, eye protection and respiratory protective equipment needed, with the type. Note face-fit testing for tight-fitting RPE. |
| Storage | Where and how the substance is stored, in labelled containers, away from incompatible materials. |
| Spill and first-aid measures | The first-aid and spill measures from sections 4 and 6 of the SDS. |
| Disposal | How waste and empty containers are disposed of. |
| Emergency arrangements | Who to call, where the spill kit and eyewash are kept, and how the SDS reaches the emergency services. |
| Health surveillance and monitoring | Whether health surveillance or air monitoring is needed, and who arranges it. |
| Review date | The date of the next review, and what would trigger an earlier one. |
| Assessor | The name, role and signature of the person who carried out the assessment, and the date. |
COSHH in your RAMS
RAMScribe writes a RAMS: a risk assessment and method statement for the whole job, not a standalone COSHH assessment. When the job uses or creates hazardous substances, the RAMS includes a COSHH assessment for each one, such as silica dust from cutting masonry. List the products you will use when you describe the job, so the RAMS names them. The assessments are written from the product names, not from the Safety Data Sheets, so check each one against the supplier's SDS before use.
FAQ
- What is a COSHH assessment for?
- A COSHH assessment identifies the hazardous substances in your work, who could be harmed and how, and the controls that prevent or adequately control exposure. The law requires one before work that could expose employees to a hazardous substance starts.
- What are the five steps of a COSHH assessment?
- HSE sets out five steps: identify the hazards, assess the risks, control the risks, record your findings, and review your controls.
- Who should carry out a COSHH assessment?
- The employer is responsible for the assessment. For small-scale work with obvious controls, HSE says you can do the assessment yourself. Where you are not sure, ask your supplier or trade association, or get professional advice, for example from an occupational hygienist.
- How often should a COSHH assessment be reviewed?
- COSHH does not set a fixed interval. The assessment must be reviewed regularly. It must be reviewed straight away if it may no longer be valid, if the work changes significantly, or if monitoring shows a review is needed.
- Do I need a COSHH assessment with fewer than five employees?
- Yes. The duty to assess applies to every employer. Only the duty to record the significant findings starts at five employees, and HSE says it still makes sense to write down what you have done.