The Control of Substances Hazardous to Health Regulations 2002 (COSHH) require employers to prevent or adequately control workers' exposure to substances that may cause ill health. A COSHH assessment is the formal process by which an employer identifies hazardous substances in the workplace, evaluates the risks they present, and determines the controls needed to protect workers and others.
What Substances Are Covered?
COSHH covers a very wide range of substances, including chemicals used or produced in the workplace, biological agents (bacteria, viruses, and other micro-organisms), dust generated by work activities, fumes, vapours, mists, and gases. Substances that are hazardous to health are those classified as very toxic, toxic, harmful, corrosive, or irritant, as well as biological agents and any substance with a workplace exposure limit (WEL) set by the HSE.
Note: COSHH does not cover lead, asbestos, or radioactive substances — these are regulated by separate legislation. However, the principles of assessment and control are broadly similar.
The Eight Steps of COSHH Compliance
- Assess the risks — identify hazardous substances and evaluate the risk of harm
- Decide what precautions are needed
- Prevent or adequately control exposure
- Ensure that control measures are used and maintained
- Monitor exposure at the workplace where necessary
- Carry out appropriate health surveillance where necessary
- Prepare plans and procedures to deal with accidents, incidents, and emergencies
- Ensure employees are properly informed, trained, and supervised
Who Needs a COSHH Assessment?
Any employer whose work activities involve hazardous substances must carry out a COSHH assessment. This includes a wide range of sectors: manufacturing, construction, healthcare, agriculture, cleaning, hairdressing, printing, and many others. Even office environments may require COSHH assessments for cleaning products, printer toner, or other substances used on the premises.
What Does a COSHH Assessment Look Like in Practice?
A COSHH assessment typically involves reviewing safety data sheets (SDS) for each substance, observing how substances are used and who is exposed, estimating the level and duration of exposure, comparing exposure levels against workplace exposure limits (WELs) published in EH40, and identifying and documenting the controls required. The assessment should be reviewed whenever there is a change in the substances used, the work process, or the level of exposure.
How Cinis Group Can Help
Our consultants carry out thorough COSHH assessments across a wide range of industries, producing clear and legally compliant documentation and practical recommendations for controlling exposure. We can also assist with health surveillance programmes and employee training. Contact us to arrange an assessment.
Editorial notice: This article is provided for general informational purposes only and does not constitute professional legal, regulatory, or health and safety advice. Whilst every effort has been made to ensure accuracy at the time of publication, laws and enforcement guidance change frequently — always verify information against current official sources such as hse.gov.uk. Any third-party names, organisations, or trademarks referenced in this article (including but not limited to the Health and Safety Executive (HSE), Network Rail, AB Agri, NEBOSH, IOSH, and IFSM) are the property of their respective owners and are referenced solely for informational purposes. Such references do not imply any affiliation with, sponsorship by, or endorsement from those organisations. © 2026 Cinis Group Ltd. All rights reserved. Reproduction of this article without prior written consent is prohibited.
