The Complete Guide to COSHH for Employers

Chris Wagstaff
blog-publish-date 21 September 2023

As an employer, you have a legal obligation to protect the health and well-being of your employees. Every year, hazardous substances may cause adverse health effects among workers, and you need to ensure you protect staff from these risks.

Poor health can significantly increase absenteeism and decrease the profits of your business. Not to mention the impact accidents have on morale, productivity and even retention

That’s why health and safety is so important in the workplace. There are an enormous number of substances that can be hazardous to your employees and to some people, you may not be aware of. This includes chemicals, dust and fumes or other substances harmful to health that you may not be aware of.

Our health and safety experts have put together a complete guide to COSHH to help you navigate your responsibilities, and what you should be aware of.

If you need immediate advice on how to handle COSHH or want to gain a better understanding of health regulations, get in touch with one of our health and safety experts on 0800 470 2723.

Croner's Complete guide to COSHH helping employees protect workers

What is COSHH?

COSHH stands for ‘Control of Substances Hazardous to Health’ and is required by law. COSHH regulations require an employer to control these substances.

A COSHH risk assessment concentrates on hazardous substances and highlights areas where control measures are needed to keep employees and other people safe.

Under the Control of Substances Hazardous to Health Regulations (COSHH, 2002), the law requires employers to either prevent, reduce, or at the very least, control exposure to hazardous substances to prevent ill health for their workers.

It is therefore an extremely broad yet detailed piece of legislation and will be different for every business. There are several substances that can be harmful to employees, and the list is too exhaustive for even the Health and Safety Executive to fully define.

Why is COSHH important?

Workers could suffer from lung disease, cancer, and skin disease because of chemical substances. These diseases cost millions of pounds each year to society, industry, and of course, the individuals affected.

The COSHH Regulations aim to keep your team out of harm’s way and reduce the number of work-related injuries and health conditions across the UK.

Breaching these regulations puts your workers at risk of harm and ill health, and non-compliance is also a crime that could result in prosecution.

By following the COSHH Regulations, a company can save money and be more effective by not having to replace trained workers – improving productivity and cutting waste. Ensuring that workers stay healthy can also lead to healthy profits. Good health is good business.

an employer competing an assessment for substances hazardous to health as the law requires.

Substances covered by COSHH

COSHH substances are hazardous to health. As mentioned before, there’s such a vast number of substances that come under the umbrella of COSHH, that it’s too difficult to list them all. For a more comprehensive list, take a look at the government's legislation. COSHH relies on a risk assessment to identify these substances in the workplace.

What hazardous substances are covered by COSHH?

The substances covered by COSHH can be divided into broader categories, such as:

  1. Chemicals.
  2. Products containing chemicals.
  3. Fumes.
  4. Dust.
  5. Vapours.
  6. Mists.
  7. Nanotechnology.
  8. Gasses and asphyxiating gasses.
    1. Biological agents (germs – If the packaging has any of the hazard symbols, then it is classed as a hazardous substance.)

Are there any substances not covered by COSHH?


  1. Lead.
  2. Asbestos.
  3. Radioactive substances.

These hazardous substances have their own set of specific regulations and control measures that employers must follow.

What are COSHH symbols?

There are many COSHH signs and symbols you need to be aware of. Some of them are common, whereas you’ll only find others in certain work environments.

You can identify these symbols by the red diamond frame and black picture at the centre.

What's the purpose of COSHH signs?

They provide quick warnings of dangerous substances. The different signs cover a variety of substances, including:

  1. Chemicals
  2. Fumes
  3. Mists
  4. Vapours
  5. Products containing chemicals
  6. Nontechnology
  7. Gases and asphyxiating gases
  8. Biological agents
  9. Germs that cause diseases

Recognising COSHH signs and understanding their meanings is crucial to keeping your staff safe. And ensuring they’re aware of the relevant dangers at work. In this next section, we’ll go through each symbol and explain what you should take from it.

COSHH symbols and meanings

Placed on the packaging of hazardous substances, COSHH symbols are there to tell you about the type of hazard a substance presents

The names below are not the official names given to each symbol. The regulations give each symbol a range of meanings. So, we may know some categories by a couple of names, for example, we sometimes refer to health hazards as 'caution'.

Health hazards (Symbol: Exclamation mark)

substances hazardous to health with an exclamation mark in a red square.

This is a general COSHH hazard symbol that indicates that there are substances dangerous to health present.

It can also be used to indicate caution due to:

  1. Respiratory irritation
  2. Dizziness and/or drowsiness
  3. Allergic reactions
  4. Serious eye irritation
  5. Skin irritation
  6. Substances harmful if swallowed
  7. Damage on contact with skin
  8. Damage when inhaled
  9. Damage to public health by causing damage in the ozone layer

Flammable (Symbol: Open flame)

a sign that provides employees with the knowldege that there is a substances hazardous to health  is flammable.

This symbol highlights flammable chemicals or substances that can ignite. Usually indicates:

  1. Flammable gas
  2. Highly flammable gas
  3. Highly flammable or flammable aerosol
  4. Highly flammable or flammable liquid or vapour
  5. A flammable solid

Serious health hazards (Symbol: Internal Damage)

a sign that shows internal damage that can seriously hurt workers particularly their lungs.

This symbol represents serious long-term threats to health, such as if a hazard can:

  1. Lead to death if swallowed or inhaled
  2. Cause damage to organs
  3. Damage fertility or affect pregnancies
  4. Lead to or cause cancer
  5. Lead to or cause genetic defects
  6. Lead to asthma or breathing difficulties if inhaled

Gasses under pressure (Symbol: Gas cylinder)

a sign showing a gas cylinder

This symbol represents a situation where gas is under pressure. This includes:

  1. Gas contained under pressure may explode when heated
  2. Refrigerated gas, could lead to cryogenic injuries

Toxic (Symbol: Skull and crossbones)

a skull a crossbone showing a toxic symbol.

This symbol represents chemicals that can cause a lot of damage in small quantities. This is usually when it:

  1. Can cause fatalities when swallowed, inhaled, or when it comes in contact with skin
  2. Can be toxic if swallowed, inhaled, or when it comes into contact with skin

Corrosive (Symbol: corrosion on hands and surface)

liquids that are corrosive to everything.

This symbol warns against chemicals that may cause damage on contact. This includes:

  1. Corrosion on metals
  2. Severe skin and eye damage

This is often found in ammonia, acetic acid, hydrochloric acid, drain cleaners etc.

Dangerous for the environment (Symbol: a dead tree and fish)

a sign showing a dead tree and fish.

This symbol represents the risk of substances that can cause serious damage to the environment. These could be immediate or long-term effects on multiple components. These are most commonly found in pesticides, biocides, petrol, etc.

Oxidising (Symbol: Open flame over a circle)

this is an oxidising sign showing an open flame over a circle.

This symbol represents chemicals that can lead to a dangerous reaction with other chemicals. This may be anything that acts as an oxidiser that could increase the intensity of the fire. It could also lead to an explosion in some cases. The symbol is usually found on bleach containers.

Explosive (Symbol: Bomb Exploding)

an explosive sign with a bomb exploding in side it.

This symbol represents chemicals, substances or any workplace occurrence that may cause an explosion. This includes:

  1. Mass explosion hazards
  2. Severe projection hazards
  3. Fire, blast or projection hazards
  4. Mass exploding in fire
  5. Unstable explosions

COSHH Responsibilities

COSHH health and safety legislation requires employers to control substances that are hazardous to employee health and anyone who comes to your premises. Control measures must be implemented and monitored by a competent person with appropriate training.

Each workplace is different and will need its own processes. However, to ensure some standardisation that protects employees, there are some essential COSHH responsibilities.

COSHH legislation outlines responsibilities for both employees and employers to ensure a safe working environment for everyone.

Employers responsibilities

Employers have the responsibility to educate and inform staff on the procedures, how to complete tasks safely and supply the correct equipment.

  1. Keep regular observations for tasks that involve these substances.
  2. Provide the right health care and checks for staff, whilst in contact with substances.
  3. Supply PPE (Personal Protective Equipment), such as eye protection and noise protection equipment. (Also check if the fit is appropriate for workers and whether any PPE needs replacing).
  4. Check employees are carrying out tasks as they are supposed to. For example, are they wearing the correct PPE? Are they handling the substances correctly?
  5. Prevent and control employees’ exposure to any hazardous substances.
  6. Supplying adequate COSHH training to staff.
  7. Provide accident plans for when accidents happen.
  8. Provide COSHH risk assessments.

Employee responsibilities

COSHH risk assessment

Employees have the responsibility to ensure that they conduct their daily tasks safely and don’t cause harm to themselves or others. They should consider:

  1. Helping their employees create a safe working environment and abide by the regulations set in the workplace.
  2. Following the procedures put in place to stop accidents and overexposure which causes harm.
  3. Wearing the correct PPE, such as eye protection and noise protection.
  4. Ensuring the PPE is stored correctly and returned to its correct storage facilities.
  5. Correctly reporting any accidents/spillages/breakages of equipment etc.
  6. Attending medical check-ups. (Some workplaces provide medical check-ups to ensure their workers are safe while working with hazardous substances).
  7. Using any cleaning and showering facilities that are provided by employers.
  8. Keeping up to date with training provided.

What is a COSHH risk assessment?

A COSHH risk assessment is a type of risk assessment that focuses on the hazards and risks from substances in your workplace. You conduct a risk assessment to minimise the risk to your staff.

It’s a thorough look at your workplace to identify all situations, products, and processes that may cause harm. After you have identified these, it is time to evaluate how likely and severe the risk is, and then decide what measures should be in place to prevent or control the harm from happening.

Performing COSHH risk assessments fall under your legal duties as an employer. You should review these assessments:

  1. Annually.
  2. Whenever you introduce a new substance to the workplace.
  3. Whenever you change a substance.

What does a COSHH risk assessment cover?

There may be certain substances or materials that immediately come to mind when you think of COSHH. Hot oils. Dangerous chemicals. A COSHH risk assessment would cover these materials but has a broader scope than you might think.

Each workplace is different and will have its own unique risks. For this reason, it may tempt you to narrow down what you cover. For example, conduct a simple “working with chemicals” risk assessment instead of a full COSHH report.

We’d recommend against this approach, as this may cause you to miss hazards that are less obvious, but still present a risk. The full scale of COSHH will cover the following aspects:

  1. Hazardous substances risk assessment.
    1. Dust.
    2. Fumes.
    3. Vapour.
    4. Mist or gas.
  2. Chemical risk assessment.
    1. Pastes.
    2. Solvents.
    3. Acids.

ensuring that all your control of substances hazardous to health meausres are in full working order is imperative to the long term health of your team.

What are the five steps to a risk assessment?

These are the steps for making a COSHH assessment and questions needed when assessing risks in your workplace:

Step 1 - Identify Hazards

The first step of your COSHH risk assessment should be identifying where the different hazards are present in your business.

You will find the information on the product labels or on the safety data sheet.

At this stage, you should also consider the harmful substances and waste gases that are produced in your processes. For example, when cutting or grinding materials you will be producing dust.

Step 2 - Who might be harmed and how

At this stage, you should look into all aspects of how your employers will be exposed. Are they breathing in the substances? Is it coming into contact with their lungs, skin or eyes? Can it be swallowed?

You should be looking at how often and how long your employees are working with the substances. Consider how the hazards are affecting other people, and who else outside your business may be exposed. That might be accidental or if they are working with them for prolonged periods of time.

Step 3 - Evaluate the risks and decide on control measures

After completing the COSHH assessment you should evaluate the risks present and assess what control measures should be in place to better protect your employees.

There are a few questions you can ask to mitigate risks.

  1. Do you need to use hazardous substances, or can you use a safer alternative?
  2. Can you change your process to eliminate the substance or avoid using it?

Step 4 - Record findings

As you are completing the COSHH assessment process you should record the hazards you find, and what measures you put in place to limit exposure.

Step 5 - Monitor

You should ensure you monitor the results of your evaluation and your COSHH assessment, this will help you identify areas that still need to be improved or highlight new risks.

This will help you ensure that your employees remain safe while they are working with potentially harmful chemicals and substances.

a worker with a mask, to control the workplace exposure limit

COSHH control measures

The last step in your risk assessment is implementing adequate control measures to prevent or reduce exposure and minimise risk. So what are some measures you can implement?

An example of a control measure is PPE (personal protective equipment) as this minimises exposure. However, the ideal control measure would control the substance itself rather than minimising exposure to it.

The first and most significant is a review of the exposure itself. Are employees exposed to hazardous waste materials as part of a work process—is it a major component of their role?

If yes, ask yourself whether you can change the process to reduce risk. If the answer is “no” then you should look at other control measures. You can usually separate these into three separate categories:


Could you create a specific contained area for harmful substances? This will help reduce the number of substances being breathed in or affecting your employee's lungs.

Could you change the way emissions are released into the environment? Installing equipment to strip the harmful substances from emissions before they are released into the atmosphere.


Look into whether the hazardous substance can be replaced by a less hazardous substance. Many hazardous cleaning chemicals can be replaced by less hazardous substances that do not require a COSHH assessment, for example most schools do not use bleach and use a less hazardous alternative.

Systems of work

Look into how you can restrict access to certain areas of your workplace where hazardous substances are being used or produced. Particularly to those without appropriate training. You should ensure that substances are stored properly, clearly labelled, and kept in the appropriate containers.


Ensuring your workplace is clean can help prevent people from breathing in or being affected by hazardous substances. Changing work surfaces to smooth worktops can make them easier to clean and prevent substances or dust from becoming trapped.

You should ensure that your team has the appropriate equipment to clean spillages quickly and safely. Any accidents must be recorded in an accident book.

COSHH regulations and your legal requirements

As an employer, you have a responsibility for the safety and wellbeing of your staff. This means being proactive about the safety of your workforce.

You can do this in several ways in relation to COSHH.

  1. Regularly conduct and update risk assessments.
  2. Report any areas of concern to management or via our company's miss reporting.
  3. Report any serious issues through RIDDOR.
  4. Inspect and review your control measures regularly.
  5. Check the safety data sheet given by your supplier.

How to write a COSHH risk assessments

Conducting a COSHH assessment in the workplace is vital if your employees are likely to be exposed to any harmful substances. To ensure you've taken adequate precautions against any risk, you should detail and record your findings.

However, putting together a COSHH template and ensuring that it is fit for purpose for your workplace can be time-consuming. That's why we have put together a general sample COSHH template you can adapt to fit your workplace, including all the key areas you need to cover.

an worker wearing full PPE after the implement control measures designed to limit exposure and comply with the regulations.

Get expert help

Croner offers practical COSHH training to keep your workers safe, whatever position they work in. We offer manual handling assessment training, practical training, and more.

It is essential you correctly manage Health and Safety at work to stay both legally compliant and profitable. With Croner’s help, you can ensure your staff are professionally trained, avoid accidents before they occur, and protect your business from risk.

So, for answers to all your COSHH questions, support with employee training, or advice on any other health & safety topic, speak to one of our experts today on 0800 470 2723.



About the Author

Chris is the Director of Health and Safety at Croner. Chris is also CMIOSH accredited, an IOSH Mentor and HSE People Champion and has over 20 years working in Health & Safety.