What Is COSHH? A Plain-English Guide for UK SME Owners

COSHH in One Sentence

COSHH stands for the Control of Substances Hazardous to Health Regulations 2002. It is the main piece of UK law that requires employers to protect workers (and anyone else) from the health risks caused by hazardous substances in the workplace.

If your business uses chemicals, creates dust or fumes, or handles biological agents, COSHH almost certainly applies to you.

What Counts as a "Hazardous Substance"?

The definition is deliberately wide. It covers:

• Commercial chemical products — cleaning agents, paints, adhesives, solvents, pesticides, and anything else that comes with a hazard label.
• Substances generated by work processes — wood dust, welding fume, flour dust, silica dust from cutting stone, and diesel exhaust emissions.
• Biological agents — bacteria, viruses, fungi, and other micro-organisms you might encounter in healthcare, agriculture, waste management, or laboratory work.

It does not cover lead (which has its own regulations), asbestos (also separate), or radioactive substances. But for the vast majority of SMEs, COSHH is the regulation that matters most.

Who Do the COSHH Regulations Apply To?

Every employer in England, Scotland, and Wales who uses, produces, or stores hazardous substances must comply. This includes:

• Sole traders with employees
• Limited companies of any size
• Charities and not-for-profits
• Schools and public-sector bodies

Self-employed people without employees are not directly covered, but they still have duties under the Health and Safety at Work Act 1974 to avoid creating risks for others.

If you are unsure whether COSHH applies to your business, the safe assumption is that it does. Some industries have specific chemical risks worth understanding — our COSHH guide for hairdressers is one example of how the regulations apply in practice.

What Are the Key Employer Duties?

The regulations set out a clear hierarchy of what you must do:

1. Assess the Risks

You must carry out a suitable and sufficient assessment of the health risks created by every hazardous substance in your workplace. This is the COSHH assessment, and it is the foundation of everything else. Our guide on how to do a COSHH assessment walks you through the process step by step.

2. Prevent or Control Exposure

Where possible, eliminate the hazardous substance entirely or replace it with a safer alternative. When that is not reasonably practicable, you must put controls in place — in this order of preference:

1. Change the process to reduce exposure (e.g. use a less dusty material).
2. Enclose the process so the substance cannot escape.
3. Use local exhaust ventilation to capture airborne contaminants at source.
4. Provide personal protective equipment (PPE) as a last resort.

PPE should never be the first or only control measure.

3. Maintain Controls

Any control measure you put in place must be properly maintained and regularly checked. Ventilation systems need testing at defined intervals. PPE must be inspected, stored correctly, and replaced when worn.

4. Monitor Exposure

If there is a risk that employees could be exposed above a Workplace Exposure Limit (WEL), you may need to carry out exposure monitoring — air sampling or biological monitoring — and keep records for at least five years (or forty years for certain substances).

5. Carry Out Health Surveillance

For certain substances — particularly those that cause asthma, dermatitis, or other chronic conditions — you must put employees under health surveillance. This might involve regular skin checks, lung function tests, or blood tests, depending on the substance.

6. Prepare for Emergencies

You need plans in place for accidents, incidents, and emergencies involving hazardous substances: spill procedures, first-aid measures, and evacuation plans.

7. Provide Information and Training

Every employee who could be exposed must know what the hazards are, what controls are in place, how to use PPE, and what to do in an emergency. Training must be repeated whenever circumstances change.

What Happens If You Do Not Comply?

The Health and Safety Executive (HSE) and local authority environmental health officers can inspect your workplace at any time. If they find COSHH breaches they can:

• Issue an improvement notice requiring you to fix the problem within a set timeframe.
• Issue a prohibition notice stopping a dangerous activity immediately.
• Prosecute the business and, in serious cases, individual directors or managers.

Fines are unlimited in the Crown Court, and custodial sentences are possible for the most serious offences. Even in the magistrates' court, fines can be substantial. Beyond legal penalties, a workplace illness caused by chemical exposure can lead to costly civil claims and lasting reputational damage.

How to Get Started

If you have never done a COSHH assessment, here is a sensible first step:

1. Walk through your workplace and list every hazardous substance you use or create.
2. Collect the Safety Data Sheet (SDS) for every commercial product.
3. Work through each substance and record the hazards, who is at risk, and what controls you have in place.
4. Decide whether your controls are adequate or whether you need to do more.
5. Write it all down, share the findings with your team, and set a review date. Our free COSHH assessment template gives you a ready-made structure to follow.

The HSE has free guidance at hse.gov.uk/coshh that walks you through the process with examples.

Making COSHH Simple with COSHHmate

For many small businesses, COSHH compliance feels like a paperwork burden. Spreadsheets and Word documents get lost, review dates slip, and new starters never see the assessments they should.

COSHHmate is built specifically for UK SMEs. It gives you a guided assessment builder, an automatic chemical register, review-date reminders by email, and instant PDF export for inspectors — all at a flat monthly price with no per-user charges.

If you want to take the pain out of COSHH compliance, create a free account and see how quickly you can get your assessments in order.