What is COSHH?
Reviewed September 2026 · Written by Complys and checked against HSE and legislation.gov.uk guidance (sources below).
COSHH stands for the Control of Substances Hazardous to Health Regulations 2002. It's the UK law that requires employers to prevent, or adequately control, workers' exposure to substances that can damage their health. Here's what that means in practice.
What COSHH stands for
COSHH is the Control of Substances Hazardous to Health Regulations 2002. It puts a legal duty on employers to assess the health risks from hazardous substances used or created at work, and then to stop or control exposure to them.
What counts as a hazardous substance
COSHH covers far more than bottled chemicals. It reaches any substance that is hazardous to health in the way it's used:
- Chemicals and products labelled with hazard pictograms
- Fumes, dusts, vapours, mists and gases
- Dust of any kind in substantial concentration in air
- Biological agents — bacteria, viruses and other micro-organisms
- Anything with a Workplace Exposure Limit, or classified as hazardous under GB CLP
What COSHH does not cover
Some hazardous substances have their own, separate regulations and are outside COSHH: asbestos (Control of Asbestos Regulations 2012), lead (Control of Lead at Work Regulations 2002), and substances hazardous only because they are radioactive. Substances that are dangerous only because they're flammable, explosive or at extreme temperature or pressure are also outside COSHH.
What COSHH requires of you
In short: assess the risk before the work starts (regulation 6), prevent exposure or adequately control it (regulation 7), keep the controls working, monitor exposure and provide health surveillance where needed, and inform and train the people doing the work.
Why it matters
Thousands of workers develop occupational asthma, dermatitis, or cancer every year from exposure to hazardous substances — harm that is often permanent. COSHH exists to prevent that harm, not to generate paperwork. A good COSHH assessment is the thing that actually keeps people well.
Build a bespoke COSHH assessment in minutes
Complys generates a COSHH assessment tailored to your actual substances and tasks — hazards, control measures, PPE, exposure limits and emergency actions — not a generic template you have to rewrite.
Sources
- HSE — Control of substances hazardous to health (COSHH)
- Control of Substances Hazardous to Health Regulations 2002 (SI 2002/2677)
- HSE — COSHH, CLP and REACH (safety data sheets)
This guide is general information, not legal advice. COSHH and chemical-classification rules change over time — always check the current HSE and legislation.gov.uk guidance for your work.
What is COSHH? — FAQs
What does COSHH stand for?
The Control of Substances Hazardous to Health Regulations 2002 — the UK law requiring employers to control exposure to hazardous substances.
What substances does COSHH cover?
Chemicals, fumes, dusts, vapours, mists, gases and biological agents — anything hazardous to health, including substances with a workplace exposure limit or classified as hazardous under CLP.
Does COSHH cover asbestos or lead?
No. Asbestos, lead and radioactive substances each have their own separate regulations and sit outside COSHH.
Is COSHH a legal requirement?
Yes. Employers must comply with COSHH 2002, including assessing and controlling exposure to hazardous substances.