27th Oct, 2020 Read time 5 minutes

How do I carry out a COSHH assessment?

The assessment and management of risks are essential to good health and safety practice, and COSHH (the Control of Substances Hazardous to Health Regulations) is an area where due diligence is crucial.

The COSHH regulations are aimed at protecting workers from hazardous substances in the workplace; they cover not only the signage used to illustrate potential hazards but also the ongoing management of the risks associated with the dangerous chemicals and other substances.

What is a COSHH assessment?

A COSHH assessment is a form of risk assessment that examines the process of using potentially hazardous substances in the workplace. According to the HSE Executive, health hazards are not limited to substances that are typically hazardous. This means that a COSHH assessment will also need to look at substances that are produced during the functioning of work tasks, like wood dust from sanding, silica dust, and air toxicity.


Step 1: Identify the COSHH relevant hazards

The first step in conducting a COSHH assessment is working out which hazards you need to look at. Have a look at the product labels and any safety data sheets concerned; these should contain information on what the COSHH hazards are in the form of relevant symbols and elements.


Step 2: Determine who are exposed and the relevant dangers

After you have worked out the relevant hazards for the COSHH assessment, you must determine who may be at risk and how they may be harmed. Analyse the current PPE used when in contact with dangerous substances, how long exposure lasts, and any other people who could become exposed (members of the public, supervisors, etc.)


Step 3: Assess the risks and determine precautionary measures

The third step in conducting a COSHH assessment requires you to evaluate the risks associated with the different substances and what can be done to protect workers and other stakeholders.

Sometimes the best course of action is removing the hazard entirely; there are sometimes viable alternatives that fill the need of the hazard with a reduced or sometimes removed hazard to the worker. Equally, you should also look at how any work processes can be altered to remove the COSHH hazard as a by-product of current practices. For example, excessive dust creation is a COSHH hazard in itself as it can threaten those with asthma +and other related conditions.

If there is no alternative the COSHH regulations require you to implement adequate control of the hazards.


1. Can you contain the COSHH substance?

Containment is a way that many employers make sure they are complying with the COSHH regulations and containment protocols are often part of any good COSHH assessment.

Can the manual handling of materials be reduced to minimise exposure to dangerous substances? And if so can it be done in a designated area to avoid the spread of any potential hazards. These are both questions worth answering when it comes to controlling the risk of COSHH substances in the workplace.


2. Can you alter the process used?

The overall working process can often be an area of improvement and a good place to start when conducting a COSHH assessment. For example, could concrete be mixed in ventilated areas as a pose to inside?


3. Plan the system of work

The system of work that you use is an area that can be used to further control hazards in a COSHH assessment. Make sure only those who need to be involved in the work are close to the hazard; also make sure the right storage containers are used for all substances.

Ensuring all COSHH substances are clearly labelled and disposed of will help reduce the overall risk.


4. Ensure proper cleaning is in place

If the hazard cannot be removed entirely, you need to ensure proper cleaning methods are in place. This includes having the right cleaning equipment to clear spills, keeping surfaces tidy and smooth to allow for easy cleaning, and other similar steps.

The HSE Executive also advises you to use ‘dust-free’ cleaning methods to prevent further exposure of hazards through dry sweeping (like vacuuming instead of sweeping).


Employers COSHH responsibilities

As an employer, you have various responsibilities when it comes to managing COSHH. Not only must you keep a record of all hazardous substances used, but you must also make sure that you are properly managing the risks associated with the hazards.


What are the employer responsibilities for COSHH?

There are a number of explicit responsibilities employers must consider as outlined by the British Safety Council below:


1. Exposure: employers need to provide appropriate PPE and exposure management for COSHH substances

2. Control measures: Employers must implement suitable control measures that are kept up to date

3. Instruction: employers must provide training on working with COSHH substances

4. Procedures: employers must have the correct protocol in place to deal with accidents

5. Surveillance: appropriate monitoring of the hazards needs to be in place

6. Risk assessments: the right COSHH assessments need to be carried out

7. Limits: employers must ensure that workers do not exceed workplace exposure limits for dangerous substances

8. Supervision: employers must ensure employees are carrying out tasks ad they should be


Make sure everyone has a good understanding of COSHH regulations and symbols

As shown a proper COSHH assessment will help you to manage the exposure to dangerous substances in the workplace. Our article shows you through the COSHH symbols and you can also find out more about what the COSHH regulations mean here.



Cooke, R.A., Gavaghan, S., Hodgson, E.B. and Moore, S., 1991. General practitioners’ awareness of COSHH regulations. BMJ: British Medical Journal, 303(6810), p.1132.

Siriruttanapruk, S. and Burge, P.S., 1997. The impact of the COSHH regulations on workers with occupational asthma. Occupational medicine, 47(2), pp.101-104.

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