Quote Request

Contact Us

My Basket (0)
What is COSHH? Everything You Need to Know and More

What is COSHH? Everything You Need to Know and More

Reading time: 30 minutes.

COSHH Overview

What you need to know

You might be surprised to learn just how many things in the workplace could cause harm or illness. If you don’t take the right steps to minimise the risks, the penalties can be severe.

As an employer, you must control exposure to materials that cause ill health in the workplace. This not only applies to employees, but to other people who might be on the premises such as visitors, suppliers or contractors.

The Control of Substances Hazardous to Health (COSHH) Regulations say that you must:

  • identify which harmful substances are present in the workplace
  • understand how people could be exposed to them and be harmed
  • put measures in place to prevent harm and review whether you’re doing enough
  • provide information, instruction and training
  • where necessary, monitor health.

Materials or substances used or created at work that could be harmful include anything from paints and cleaners to blood and waste. Dusts, gases, fumes that you breathe in or liquids, gels or powders that could come into contact with eyes or skin can all be harmful. Micro-organisms can cause infections, allergic reactions and some are toxic.

What you need to know about COSHH

What happens if you fail to comply with the COSHH regulations?

Many substances can harm health but, used properly, it’s rare that they do. However, if you fail to control their use you could be guilty of offences under Section 33 of the Health and Safety at Work Act (HSWA).

The maximum penalty in the magistrates’ court is an unlimited fine and a prison sentence of up to six months. In the Crown Court, the maximum penalty is an unlimited fine or imprisonment for up to two years.

Orders to carry out work in the community can also be made and you can be disqualified from creating, liquidating or managing a company related to the offence.

In some cases, you can be required to take remedial action. Your organisation can also be required to publish information about the offence and the sentence, if you are found guilty of corporate manslaughter.

Both courts can award unlimited compensation for personal injury or damage as a result of the offence. If someone has died, relatives and dependants can be awarded compensation for their bereavement and for funeral expenses.

What you will discover in this guide

Reading this guide will provide you with information about your responsibilities as an employer under the COSHH regulations . You will find out about the principles you will need to follow to protect your employees and to meet your health and safety requirements.

You will gain a greater understanding of substances that are potentially hazardous to health that are used in the workplace, and how to complete a proper COSHH assessment. Adequate control measures and the monitoring and health surveillance processes are explained, along with incident planning and how to deal with a COSHH emergency.

You will also find out more about related assessments you will need to make for the Registration, Evaluation, Authorisation and restriction of Chemicals (REACH) and what you should report under the Reporting Injuries, Diseases and Dangerous Occurrences (RIDDOR) regulations.


What is COSHH

The Control of Substances Hazardous to Health (COSHH) regulations explain what you should do as an employer to control substances that are hazardous to health. You can prevent exposure to harmful substances by:

  • finding out what the health hazards are
  • deciding how to prevent harm to health (a COSHH risk assessment)
  • providing control measures to reduce harm to health
  • making sure your controls are used properly and consistently
  • keeping all your control measures in good working order
  • providing information, instruction and training for employees and others who might use or visit the workplace
  • providing monitoring and health surveillance as needed
  • planning for incidents and emergencies.

Many businesses produce mixtures of substances or products that can be harmful such as paints, bleach or dust. Sometimes it’s easy to recognise what’s harmful, but it isn’t always obvious.

Back to index

What are hazardous substances?

A substance or mixture of substances is hazardous if it has the potential to cause harm if inhaled, ingested, if it comes into contact with or is absorbed through the skin These can include:

  • chemicals
  • products containing chemicals
  • fumes
  • dusts
  • vapours
  • mists
  • nanotechnology
  • gases
  • biological agents that can cause harm or disease

Some of these substances can cause asthma or cancer. Many can damage the skin, and some can cause serious long-term damage to the lungs.

The effects can be immediate, such as dizziness or stinging eyes, or they can take many years to develop, such as lung disease. Many of the long-term or chronic effects cannot be cured once they develop.

The COSHH Regulations apply to substances:

  • included in Table 3 in Annex VI of the Classification, Labelling and Packaging (CLP) Regulation which are specified as very toxic, toxic, harmful, corrosive or irritant
  • with a Workplace Exposure Limit (WEL) approved by the Health and Safety Executive (HSE)
  • that are biological agents that might cause infection, allergy, toxicity or other hazards to human health
  • are dusts that are inhalable or respirable at specified concentrations over an eight-hour period
  • used in the workplace that have chemical or toxicological properties that could create a risk to health.

CLP Regulations

Substances classified as very toxic, harmful, corrosive or irritant.

Health and Safety Executive

Substances with an approved Workplace Exposure Limit.

Biological Agents

A hazard to human health

Inhalable or respirable dust

Above specified limits.

Substances used in the workplace

With harmful chemical or toxicological properties.

COSHH does not cover:

These have their own regulations, but it is important to display harmful substances signage to ensure everyone is aware that they are present.

Harmful substances signage
Back to index

What is exposure?

Exposure is when a substance is taken into your body. This can happen when you:

  • breathe fumes, dust, gas or a mist
  • have skin contact
  • break you skin with a scratch, cut or accidental injection
  • swallow something.

Around 500 substances have Workplace Exposure Limits (WELs). To know whether you are staying within these limits, you will need to monitor them.

If a hazardous substance doesn’t have an exposure limit, or it is mixed in a product, you will need to complete a COSHH assessment and put a suitable plan in place to control any risks.

Back to index

What does COSHH mean for employers?

COSHH emphasises the need to prevent exposure to harmful substances in the workplace. If this can’t be avoided, you must have good practices in place to control exposure.

As an employer you must:

  • consider all routes of exposure when developing control measures, including inhalation, absorption through skin and ingestion
  • maintain health and safety by making sure that the introduction of control measures does not increase the overall risk
  • minimise emission, release and spread of substances that are or could be hazardous to health through properly designed and operated processes and activities
  • use the most effective and reliable control options to minimise the escape and spread of substances hazardous to health
  • provide suitable personal protective equipment when exposure can’t be controlled adequately by other means
  • inform and trainyees on the hazards and risks of the substances they work with
  • make sure control measures are followed properly to minimise risks
  • regularly review and check control measures to make sure they continue to be effective.

Evaluate Risk



Review and Revise

Consider all routes of exposure

Maintain health and safety

Minimise emission, release and spread

Provide personal protective equipment (PPE)

Inform and train employees

Make sure control measures are followed

Review and update controls regularly

Back to index

Why COSHH is important for your business

A robust COSHH risk assessment will identify substances that you might not have realised could pose a risk. It will help you to understand why they’re hazardous so that you can put measures in place and avoid causing harm to anyone unknowingly.

Although some substances might be harmless alone, they might become hazardous when combined with something else, so it’s also a good way to identify potentially dangerous combinations, and what could happen if they are mixed.

As part of the process you can assess whether you are using the best substances or if they could be replaced with something less hazardous.

By following the principles of COSHH you will put adequate controls and emergency procedures in place to minimise the risks for your business, your employees, visitors and members of the public.

You are likely to identify other requirements, such as the proper disposal of waste products, which will help your business to comply with the regulations.

COSHH applies to the storage and transportation or hazardous substances, so you will also know that you are handling them in the right way at all times, minimising the risk of accidents.

You might also need to put a health surveillance system in place to detect any early signs of illness and to continually review the risks and measures you have in place. In some cases this will be a legal requirement.

Your system should include a process for your employees to raise any concerns they have about your current control measures or their training. They are best placed to know if something has been missed in your day-to-day practices.

Your COSHH assessments will also highlight any processes that your local authority should know about.

Ultimately the penalties for failing to comply with the regulations can be severe. People’s health could be damaged. Someone might even die. Even if nobody actually comes to harm, your business could be closed and the adverse publicity you could face would damage your reputation.

Back to index

COSHH principles

The objective of COSHH is to prevent ill health by removing or adequately controlling exposure to hazardous substances in the workplace.

Steps you can take include:

  • total or partial enclosures and proper ventilation and security measures
  • ways of working, including supervision and training that reduce exposure
  • regular maintenance, examination and testing of control measures
  • regular reviews to make sure your employees follow the control measures.

Managing the way people work, the frequency of exposure and the number of employees nearby, can also help to minimise risks.

COSHH principles
Back to index

COSHH ways of working

You can introduce many effective COSHH controls by managing ways of working, including operating procedures, supervision and training.

This should include emergency procedures, decontamination and permits to work for work in a specified time-frame, such as planned maintenance, for example.

It also involves testing all your control measures regularly to make sure that your controls are properly applied. This should include how equipment is used, working practices and behaviour.

You should keep records of examinations, tests and equipment repairs for at least five years to identify any trends or variations in equipment reliability and performance.

Where control measures are in place it is important to use them properly. This includes:

  • wearing any personal protective equipment (PPE) that is needed
  • using control equipment
  • following hygiene procedures
  • warning supervisors if anything appears to be wrong.
Back to index

What is a COSHH assessment?

Hazards and risks in the workplace don’t just relate to substances labelled as ‘hazardous’.

You must look out for potential risks of exposure to any substances that might be hazardous to health.

You are responsible for finding out whether there are risks associated with the use of some substances or combinations of products or the processes that you use. These could include fumes from welding or soldering, mist from metalworking, dust from quarrying, or gases from silage, for example.

You can find a lot of industry-specific information on the HSE website.

The Chemicals (Hazard Information and Packaging for Supply) Regulations, sometimes known as CHIP, describe the procedures for classifying dangerous substances and dangerous preparations. Safety Data Sheets (SDS) should be provided when these substances are supplied.

There is an internationally agreed standard for SDSs, Materials Safety Data Sheets (MSDS), and Product Safety Data Sheets (PSDS). It is defined in a globally harmonised system for the classification and handling of chemicals (GHS).

There are sixteen sections in a standard SDS to provide you with information that will allow you to protect human health and the environment

They describe the hazards the chemical presents, and give information on handling, storage and emergency measures in case of accidents.

By law, your supplier must give you an up-to-date safety data sheet for a substance that is ‘dangerous for supply'.

When you know you are using a hazardous substance in the workplace you will need to carry out a COSHH assessment and have appropriate control measures.

You will need to look in detail at:

  • how and why you use the substance
  • the possible ways this could affect your employees’ safety
  • who else could be affected such as contractors, visitors or neighbouring businesses
  • how often people might be exposed to the substance
  • the likelihood of an accident or incident
  • the level of risk.

Handling small amounts of chemicals in a can could be assessed as a low-risk activity, however the cleaning or disposal of drums that have contained the substance might be a greater risk, requiring more control measures.

Your COSHH assessment should be recorded in writing, along with the measures you are taking to reduce risk. You are legally required to do this if you have five or more employees, but it is good practice anyway.

You should always be reviewing the level of risk, by checking your Accident Book for examples of burns from splashes, nausea or light-headedness from solvents, for example.

You can make a start using our COSHH Assessment template.

Download Free COSHH Assessment Template
Back to index

COSHH assessment - step-by-step guide

The HSE provides an online tool called COSHH Essentials, which sets out basic advice on what you should do to control exposure to hazardous substances in the workplace.

It provides advice in ‘factsheets’ called ‘control guidance sheets’ for common substances and processes. Direct advice sheets are also available for specific industries and applications.

Four-step guide to a COSHH assessment

Step 1 – collect information

It’s a good idea to give someone responsibility for ensuring that you meet your COSHH obligations. You might also want to work with a consultant to make sure you are following current good practices.

Consider what your business does and the processes and systems you use in the workplace. Create a record of any substances that could be hazardous and the effects they could have.

You can then create a much clearer picture of who could be exposed and how.

Step 2 – evaluate the risks

You might need to look at the risks for individuals and groups as well as assessing the likelihood that a substance could cause harm. You will also need to know when and how often exposure could occur, how extreme the exposure could be and for how long.

You can then start to define what risks exist and when exposure could be harmful to health.

Step 3 – identify control measures

It’s important to identify control measures that will remove or adequately reduce risks to health, but you must also make sure that these measures can and will be properly used. You should include monitoring, health surveillance, information and training. You should also consider emergency situations and how you would respond, in the event of a fire, for example.

Step 4 – create a record

Make a record of what you have done, your conclusions and the measures you have put in place. You should also include a date when you will review the risks and control measures again.

Back to index

What is a COSHH policy?

Your COSHH policy should clearly state your commitment to protect employees and others from the risks of exposure to hazardous substances.

Managers, professional advisors and employees should all understand their roles and responsibilities. They should be encouraged to be aware of the possible risks of hazardous substances in the workplace at all times and to follow principles of good practice.

COSHH Policy

Your policy should include how frequently risks should be reviewed and the circumstances that might require an immediate review or revision of your COSHH risk assessment and procedures.

You can use our COSHH Policy Template as a starting point.

Back to index


REACH stands for Registration, Evaluation, Authorisation and restriction of Chemicals.

COSHH and REACH work together and both require a risk assessment. However, while there are some overlaps there are also differences.

The main obligations are:

Who must assess risk? The employer Mostly the manufacturer or importer
What substances? Hazardous to health, including those arising from processes and germs Manufactured or imported in quantities of 10 or more tonnes per year in the EU
What duty? Control exposure in all uses by site- and process-specific measures Develop exposure scenarios and identify ‘Risk Management Measures' for named tasks and procedures

REACH identifies a Derived No Effect Level (DNEL) for substances. This is a benchmark and not an exposure limit. The manufacturer or importer uses the DNEL to identify the correct Risk Management Measures (RMM) for your task or procedure in an ‘exposure scenario’.

Exposure scenarios and the Risk Management Measures appear in the REACH Safety Data Sheet for each substance or product.

Using the RMM in the Safety Data Sheet you should ensure you meet the DNEL. Good control practices, like those in the HSE’s COSHH Essentials, are likely to meet the requirements of any Workplace Exposure Limit.

The requirements of both should be consistent, but if your COSHH assessment requires extra controls, these should be used.

If the RMM doesn't cover your task or procedure, tell your substance supplier. If you want to keep your use a secret, go to the REACH website pages for advice.

Back to index


As an employer you must report work related accidents, diseases and dangerous occurrences under the Reporting Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR).

Diseases that should be reported include:

  • dermatitis
  • skin cancer
  • lung disease
  • hepatitis.

Biological agents – COSHH defines biological agents as micro-organisms, cell cultures or human endoparasites which may cause infection, allergy, toxicity or other hazards to human health.

Diseases and acute illnesses needing medical treatment must be reported when they are due to a work-related exposure to a biological agent.

For example, this might be due to:

  • an event, such as the accidental breakage of a laboratory equipment, accidental injury with a contaminated syringe needle or an animal bite
  • unidentified events, where someone is exposed to the agent without their knowledge such as legionella bacteria, while conducting routine maintenance on a hot water service system.

A report should be made whenever there is reasonable evidence suggesting that work-related exposure is the likely cause of a disease.

Occupational dermatitis - dermatitis associated with work-related exposure to chemical or biological irritants or sensitising agents should be reported. This includes any chemical with the warning ’may cause sensitisation by skin contact’, or ’irritating to the skin’. Epoxy resins, latex, rubber chemicals, soaps and cleaners, metalworking fluids, cement wet work, enzymes and wood can all cause dermatitis.

Corrosive and irritating chemicals can also lead to dermatitis. This can happen in construction work, health service work, rubber making, printing, paint spraying, agriculture, horticulture, electroplating, cleaning, catering, hairdressing and floristry.

Occupational asthma - asthma associated with work-related exposure to any respiratory sensitiser should be reported. This includes exposure to chemicals with the warning ‘may cause sensitisation by inhalation’. Known respiratory sensitisers include epoxy resin fumes, solder fumes, grain dusts, and wood dusts.

Asphyxia (lack of oxygen) – this could happen when a person enters an atmosphere with very little oxygen, such as a confined space, or is exposed to poisonous gases.

Diagnosis - a doctor must diagnose a reportable disease, identifying new symptoms, or any significant worsening of existing symptoms. As the employer, the doctor will provide the diagnosis to you in writing. They are encouraged to use standard wording to describe reportable diseases in a written statement.

Dangerous occurrences - incidents that could potentially cause death or serious injury, but which rarely happen, should be reported. This will help the enforcing authorities to learn the causes so that regulators and employers can prevent accidents in the future.

This could include unintentional release or escape of any substance which could cause personal injury or the malfunction of breathing equipment likely to cause a significant risk of personal injury or that leads to first-aid or medical treatment.

Keeping records - You must keep a record of any reportable injuries, diseases and dangerous occurrences. You can make your RIDDOR report online and download an electronic copy to save and print.

Your records must include:

  • the date and method of reporting
  • the date, time and place of the event
  • personal details of those involved
  • a brief description of the nature of the event or disease.

Accidents must be recorded in the accident book (B1510) although a separate method will be needed for diseases.

If you think your insurer needs to know about a work-related accident, injury or ill health, notify them quickly to save you time and money.

Back to index

Dealing with COSHH emergencies

You need a plan and good practice guidance to use in emergency situations, accidents, and incidents. This should include:

  • right equipment to deal with an emergency such as a spill, including protective equipment and decontamination products
  • procedures to deal with an injury
  • training
  • arrangements to deal with waste and contaminated materials.

It is important to have accurate information about the substances you are using, their location and details of the incident for the emergency services.

Your emergency plans should be widely shared with your safety representatives, employees, other users at your premises and third parties who could be affected.

COSHH emergency

Hazardous materials handling - safety information

Your employees must know what to do to prevent exposure to dangerous chemicals and what to do if there is an emergency. A poster in a prominent place can provide a checklist for safe working procedures for example.

A general COSHH poster should include advice on precautionary steps, control measures and monitoring exposure to harmful substances. The aim is to minimise the chances of injury, to make sure that people know how to work safely, and what to do in an emergency.

Additional information should be provided about the correct use and cleaning of PPE, GHS label classifications and who to contact for further information and support.

Back to index

Monitoring and surveillance

Once you have implemented your hazard control measures you will need to make regular checks so that you know your processes are working as you intended.

You need to keep a constant lookout for any uncontrolled contaminants and make sure your employees receive COSHH training. Health checks for some team members might also be needed.

Back to index

Incident planning

Your risk assessment should include a review of the implications of incidents and accidents involving the substances you have identified. You will need to produce an emergency response plan. This might include the availability of first aid supplies, and how technical information about the substances you use that can be quickly passed to emergency services if needed.

Make sure alarms and communication systems are in place to alert your staff of any problems and that you and have clear signage for escape routes if an evacuation is needed.

Substances and storage units must have GHS (Globally Harmonised System of Classification and Labelling of Chemicals) labels.

Your incident plans should be checked regularly for suitability and adapted if necessary.

Back to index

The purpose of a COSHH assessment

Once you have carried out a risk assessment and identified which harmful substances are present, and how people could be harmed, you need to think about preventing exposure.

This might include changing your processes to use different, safer substances. Where this isn’t possible, you must put adequate control measures in place to reduce exposure.

The measures you use could include:

Changing the process to reduce risks - You could lower the temperature of a process to reduce the amount of vapour getting into the air or use pellets instead of powders as they are less dusty.

Containment - Enclosing the process to minimise the escape or release of the harmful substances, using closed transfer and handling systems and extraction equipment near to the source.

Working practices - Restricting access and planning the storage of materials, using appropriate containers and disposal of waste.

Cleaning - Making sure that the workplace can be easily and effectively cleaned using a ‘dust-free’ method such as vacuuming, with smooth work surfaces and well-defined procedures for equipment use and to clear up spillages quickly and safely.

If you transport chemicals, you should look at the Carriage of Dangerous Goods (CDG) and Use of Transportable Pressure Equipment Regulations 2004.

Back to index

COSHH controls

Your risk assessment will define the control measures needed for each activity and substance.

You can reduce the risk by using a different substance, for example. You can enclose work areas and control the number of employees who use the substance. Alternatively, your operating processes and equipment might need to be changed.

You might need equipment for carrying and storing containers such as drums or cylinders. Spill-containing cupboards to safely store smaller amounts of chemicals or flammable materials might be needed.

You will also need waste disposal systems to prevent contamination and industrial-strength cleaning equipment and products.

Personal protective equipment (PPE) such as gloves, facemasks and protective overalls are also an important part of COSHH hazard control when risks can’t be further reduced by using alternative materials or working practices.

All of your control measures must be checked and reviewed regularly to make sure they continue to be effective.

These checks should be used to find out where improvements are required. They should include:

  • maintenance of ventilation equipment including regular examination and testing by a competent person.
  • measuring the airflow or the pressures in the system, or air sampling in the workroom.
  • all local exhaust ventilation (LEV) systems must be examined and tested at least every 14 months
  • regularly reviewing working practices to make sure guidance is being followed making changes when needed
  • making sure PPE is suitable, properly fitted, used and maintained.

Take specialist advice when you need it, especially for potentially serious risks or processes that are difficult to control. Work with someone who is competent in the relevant area of work such as an occupational hygienist. The British Occupational Hygiene Society website has more information.

COSHH symbols

There are nine primary hazard symbols relating to COSHH.

COSHH danger symbol
COSHH warning symbol
COSHH Long-term health hazard symbol
Long-term health hazard
COSHH danger to environment symbol
Danger to environment
COSHH corrosive symbol
COSHH flammable symbol
COSHH oxidiser symbol
COSHH explosive symbol
COSHH compressed gas symbol
Compressed gas

While some of these COSHH signs and symbols might be immediately clear, others have very specific meanings.

  • Toxic – even at low levels some substances can cause damage to health. When the sign includes a T+ in the top left-hand corner, it means the substance can cause damage to health, even at very low levels.
  • Long-term health hazards - cancer-causing (carcinogenic) substances can cause respiratory, reproductive or organ damage over time leading to a chronic long-term condition.
  • Danger to the environment – a substance might present an immediate or delayed danger to wildlife, plant life, people, or weather systems for example.
  • Corrosive – contact with some substances can lead to chemical reactions that damage or destroy other materials. Corrosive substances can include liquids, solids, gases, mists and vapours.
  • Oxidising – some substances and preparations can react together to create heat (exothermically) and can lead to fire. Common oxidising agents are oxygen, hydrogen peroxide and halogens.
  • Caution - some hazardous substances might not represent an immediate or severe risk to health but should be handled carefully in the workplace.
Back to index


Employers are responsible for providing, replacing and paying for personal protective equipment (PPE).

PPE should be used when all other measures to controls exposure are inadequate. It protects only the wearer, while being worn. If it fails, PPE often offers no protection at all.

Types of PPE include:

To choose the right PPE you will need to consider:

  • suitability
  • level of protection
  • training or maintenance
  • a replacement schedule.

Your employees need to know why they need PPE and must be trained to use it correctly. Things you and your employees should consider include:

  • proper fit
  • comfort
  • compatibility
  • suitability for the role or function
  • other health risks such as overheating or being caught in machinery
  • maintenance or cleaning requirements.
COSHH PPE Back to index

Disposal of COSHH materials

Chemicals need to be safely treated, disposed of, and recycled.

There are three broad categories of hazardous waste:

  • always hazardous
  • never hazardous
  • could be hazardous and need to be assessed.

Some chemicals might also be fire hazards such as petrol and paint thinners.

When storing hazardous waste, the presence of other materials like packaging and sawdust can add to the risk if not properly managed.

Your COSHH assessment must include safe working practices for dealing with hazardous waste, to ensure that it is stored, handled and transported correctly. Accidents can also be caused by mixing incompatible chemicals, or from careless disposal of unstable chemicals, so it’s important to understand how chemical waste should be treated.

If you produce, transport, or receive hazardous waste you will have responsibilities under the Hazardous Waste Regulations.

Back to index

The COSHH register

A COSHH register provides a record of the hazardous substances you have use and is an important part of your COSHH assessment.

Keeping a list of all substances used or generated in your workplace will help you to create an effective COSHH control system and remain compliant with the regulations.

You will have:

  • an easy-to-use overview of the hazardous substances in use
  • a record of when substances were last assessed
  • details where substances are used and stored
  • the location of important documents such as the Safety Data Sheets and your COSHH assessment for the substance.

Your register will help you to identify when further action is needed, such as reviewing your assessments and control measures.

If you develop your COSHH register in an electronic format, including your records and data sheets, your COSHH inventory can link through to the documents, making access and maintenance of your COSHH system easier to manage.

You can use our COSHH register template to start the process.

Back to index

COSHH training

As an employer you should provide information, training and instruction for your employees if they work with substances hazardous to health, including your cleaning and maintenance staff. You should keep a record of the training you have provided.

Your employees need to understand the risks you have identified in your COSHH assessment:

  • the hazards and risks
  • workplace exposure limits
  • results of exposure monitoring
  • general results of health surveillance
  • what to do if there is an accident or emergency.

Your employees should also have access to Safety Data Sheets.

They should also be kept informed about planned future changes in processes or substances used.

When a contractor comes on site, they should be informed about any risks and how you are controlling them. You need to know if they are bringing hazardous substances onto your premises, and how they will prevent harm to your employees.

Training providers could include your local colleges, trade associations, the Royal Society for the Prevention of Accidents, suppliers of ventilation and safety equipment, and consultants.

What is a COSHH certificate?

Many training providers, including the Royal Society for the Prevention of Accidents, offer chemical safety courses that will give your employees an understanding of how substances can harm health.

The course should cover the basic requirements of COSHH, including:

  • types of chemical and biological hazards
  • classification of hazardous substances
  • types of exposure
  • health hazards of specific substances
  • the purpose of COSHH
  • workplace exposure limits (WELs) and other sources of information
  • control measures
  • monitoring and surveillance
  • environmental issues
  • a practical guide to the COSHH risk assessment.

On completing the course your employees will normally receive a certificate of training. Although there isn’t a requirement to renew validity of a COSHH certificate, it would be good practice to repeat the training at least every three years.

Back to index

COSHH monitoring

You will need to be able to demonstrate that your COSHH controls are adequate. The best way to do this is through a thorough monitoring process. This is separate from any health surveillance you might put in place for your employees.

Effective monitoring will:

  • show how you comply with a WEL (Workplace Exposure Limit) or BMGV (Biological Monitoring Guidance Value)
  • confirm that the control equipment and personal protective equipment you are using provides enough protection.

Personal air monitoring can also be used to measure how much of a substance is inhaled.

Biological monitoring measures how much of a substance has entered the body.

You should also use your monitoring system to ensure that contamination is controlled using surface wipes, screening, colorimetric detectors tubes, and meters.

COSHH health surveillance

In addition to monitoring processes, health surveillance might be needed to protect employees from health risks at work. It involves collecting and reviewing information about their health in order to:

  • protect them through the early detection of adverse physical changes or disease
  • collect data that will help to detect or evaluate health hazards
  • evaluate control measures.

You would need to undertake health surveillance when:

  • there is a disease associated with the use of a substance such as asthma, dermatitis or cancer
  • adverse physical changes can be detected to reduce the risk of further harm
  • working conditions increase the likelihood of disease.

Tests, questionnaires or examinations aren’t enough under these circumstances. Your health surveillance process should involve regular planned assessments of aspects of your employees’ health such as breathing problems or skin conditions for example. The results must then be professionally interpreted so that you can take action to eliminate or control further exposure.

To be completed effectively you will need to work with a qualified and experienced occupational health doctor or nurse. If a GP offers the service, you need to be sure that they are competent in occupational medicine.

Your health surveillance service provider must interpret the results of health surveillance for each individual and supply general information for you to keep up-to-date health records. They might also be able to anonymise and group the information to highlight trends.

COSHH Health Surveillance Process

Summary of the key points in this guide

Having read this guide you will understand the basic principles of COSHH and your responsibilities as an employer.

You will be able to plan a proper COSHH assessment and will understand the types of control measures and monitoring you can put in place to protect your employees from substances and can be hazardous to health.

You will also appreciate the importance of incident and emergency planning.

Back to index

What is COSHH - frequently asked questions

What does COSHH stand for?

COSHH stands for 'Control of Substances Hazardous to Health' and is a set of regulations to protect employees from ill health when working with specific substances and materials.

COSHH requires employers to identify and manage the hazards and risks from substances in a workplace.

How is COSHH monitoring carried out?

Monitoring involves measuring your employees exposure to specific substances that can be harmful to health. Exposure could be by inhalation, skin contact, or swallowing.

The monitoring process can include static or background monitoring to check on the performance of extraction equipment and to understand the potential for visitors or contractors to be exposed. Air monitoring can measure exposure through inhalation and biological monitoring, with consent, can be used to measure exposure through the skin or ingestion that could affect health.

COSHH monitoring is required:

  • to help select the right controls
  • where substances used in the workplace are a serious health risk
  • to check that exposure limits are not exceeded and your control measures work well enough
  • to help choose the right amount of respiratory protection
  • to identify any need for health surveillance
  • when an inspector has issued an enforcement notice that requires you to monitor exposure.

It is important to be aware that measuring exposure is not an alternative to controlling it. Since exposure can vary from day to day, your results must be no more than a fraction of the safe exposure limit, for example below one third.

Monitoring always requires co-operation from your employees, whilst doing their jobs as normally as possible, and they should be kept informed of the results.

Where should COSHH products be stored?

You must have procedures in place to reduce or prevent exposing your employees to hazardous substances and that includes safe storage.

The most common hazardous materials at work are chemicals and products containing chemicals. If not kept safely, these could pose a direct risk to your employees if there is an accident. Chemicals of different types need to be stored separately from others and your COSHH risk assessment should identify these.

They could include explosives, self-reactives and organic peroxides, which should not be stored with any other chemicals.

Compressed gases in cylinders under pressure have the potential to explode if they are exposed to fire or extreme heat. They might contain flammable or non-flammable substances, but their contents could be toxic, so you should take advice about those that should be segregated.

Many chemical liquids are flammable, and some can spontaneously ignite when exposed to air (pyrophorics). Your risk assessment should determine how these should be stored and handled in a safe way.

To provide the highest standards of safety of you might need to use one or more COSHH cabinets.

Does COSHH apply to self-employed people?

If you don’t have employees, but you take hazardous substances to other people’s premises, then all parts of COSHH regulations apply except those about monitoring and health surveillance.

Even small quantities of chemicals can lead to ill health or injury. Your COSHH assessment should look your processes, how the chemicals will be used with other substances and any reactions that might happen. You can use the safety data sheet to find out more information. The controls you put in place should eliminate or reduce the risk of possible accidents, incidents and emergencies involving hazardous substances.

What are Safety Data Sheets for?

Safety Data Sheets provide information on chemical products that help users to make a risk assessment. They describe what hazards could arise from using and storing the chemicals and give information on emergency measures in case of accidents.

If a substance is dangerous for supply*, the supplier must send you a data sheet:

  • when the product is first ordered
  • if the formulation changes
  • if you ask for a sheet.

If it is not dangerous for supply the supplier should include instructions for safe use with the package. Report suppliers who refuse to provide safety information to the HSE.

*HSE L131 - Approved Supply List. Information approved for the classification and labelling of substances and preparations dangerous for supply (Seventh edition)

Back to index