COSHH Regulations UK: The Complete Guide to Compliance

Every day on UK construction sites, workers handle substances that can cause serious health problems. Cement dust irritates skin and airways. Solvent vapours damage the nervous system. Wood dust, at high concentrations, is a known carcinogen. Without proper controls, these everyday materials become silent killers.

COSHH regulations exist to prevent this harm. The Control of Substances Hazardous to Health Regulations 2002 (COSHH) requires employers to assess and control exposure to hazardous substances. It applies to virtually every workplace in the UK, and getting it wrong can mean enforcement notices, prosecution, and most importantly, sick workers.

This guide covers everything you need to know about COSHH compliance: what the regulations require, the 8 principles of good control, how to conduct assessments, and specific guidance for construction. Whether you're a site manager, health and safety officer, or business owner, you'll find practical steps to protect your workforce.

What is COSHH and What Does It Stand For?

COSHH stands for the Control of Substances Hazardous to Health. The current regulations came into force in 2002, replacing the original 1988 version. They sit within the broader framework of UK health and safety law, working alongside the Health and Safety at Work Act 1974 and the Management of Health and Safety at Work Regulations 1999.

The purpose of COSHH is straightforward: to protect workers and others from the health risks created by hazardous substances used at work. This includes chemicals, products, fumes, dusts, vapours, mists, gases, and biological agents.

COSHH applies to almost all workplaces. If your business uses any substance that could cause harm to health, COSHH applies to you. This includes construction sites, manufacturing facilities, healthcare settings, laboratories, cleaning companies, and offices (yes, even toner and cleaning products count).

The full text of the regulations is available at legislation.gov.uk.

What Substances Are Covered by COSHH?

COSHH covers any substance that could cause harm to health through exposure at work. This is broader than most people realise. Hazardous substances fall into several categories:

Chemicals and Products with Warning Labels

Any product displaying a hazard pictogram (the red diamond symbols) is covered by COSHH. This includes cleaning chemicals, adhesives, paints, solvents, acids, and thousands of other products used daily on construction sites.

Substances Created by Work Activities

Many hazardous substances are created by the work itself. Wood dust from sawing. Silica dust from cutting concrete. Welding fumes from joining metals. These don't come with labels, but they're just as dangerous and fully covered by COSHH.

Biological Agents

Bacteria, viruses, fungi, and other micro-organisms that could cause infection or disease are covered. This includes legionella in water systems, moulds in damp buildings, and bloodborne pathogens in healthcare.

Construction-Specific Examples

On construction sites, common hazardous substances include: cement and concrete (causes dermatitis and burns), silica dust from cutting and grinding (causes silicosis and lung cancer), wood dust (causes asthma and nasal cancer at high exposure), welding fumes (causes metal fume fever and respiratory problems), isocyanates in paints and foams (causes occupational asthma), solvents in paints and adhesives (causes neurological damage), and diesel exhaust emissions in enclosed spaces (causes cancer).

What COSHH Does NOT Cover

Some hazardous substances have their own specific regulations: asbestos is covered by the Control of Asbestos Regulations 2012, lead by the Control of Lead at Work Regulations 2002, and radioactive substances by the Ionising Radiations Regulations 2017. Substances that are hazardous only because they're flammable, explosive, or under pressure are covered by different regulations.

For detailed guidance on what COSHH covers, see the HSE COSHH basics page.

The 8 Principles of Good Control Practice

The COSHH regulations set out eight principles of good control practice. These aren't optional extras; they're the foundation of effective control. Every employer must apply these principles when designing and implementing control measures.

1. Design and Operate Processes to Minimise Emission, Release and Spread

The best control starts with the process itself. Can you redesign the work to generate less dust, fewer fumes, or less contamination? On a construction site, this might mean using pre-cut materials instead of cutting on site, or using water suppression when cutting concrete.

2. Take Into Account All Relevant Routes of Exposure

Hazardous substances can enter the body three ways: inhalation (breathing in), skin contact (absorption or direct damage), and ingestion (swallowing). Different substances present different risks. Cement dust is primarily an inhalation hazard, but wet cement causes severe skin burns. Your controls must address all relevant routes.

3. Control Exposure by Measures Proportionate to the Health Risk

Match your controls to the level of risk. A substance that causes mild irritation doesn't need the same controls as a known carcinogen. This principle prevents both under-protection and the wasteful over-engineering of controls for low-risk substances.

4. Choose the Most Effective and Reliable Control Options

This is where the hierarchy of controls comes in. In order of effectiveness: elimination (remove the hazardous substance entirely), substitution (replace it with something less hazardous), engineering controls (LEV, enclosure, automation), administrative controls (procedures, training, supervision), and PPE (as a last resort only).

5. Where Adequate Control Cannot Be Achieved by Other Means, Provide Suitable PPE

PPE is the last line of defence, not the first. It should only be used when other controls cannot adequately reduce exposure. When PPE is needed, it must be suitable for the hazard, properly fitted, and maintained in good condition.

6. Check and Review Regularly the Effectiveness of Control Measures

Controls can deteriorate or become less effective over time. Regular checks ensure that extraction systems still work, that procedures are being followed, and that PPE is being used correctly. Review controls whenever circumstances change, after incidents, or at least annually.

7. Provide Information, Instruction and Training for Employees

Workers have a right to know what hazards they face and how to protect themselves. Training must cover: what hazardous substances they work with, what the health risks are, what control measures are in place, how to use controls and PPE properly, and what to do if something goes wrong.

8. Ensure That Control Measures Are Properly Used and Maintained

Providing controls isn't enough; you must ensure they're actually used. This requires supervision, enforcement, and a culture where shortcuts aren't tolerated. Maintenance schedules must be followed, and any defects reported and fixed promptly.

The HSE provides detailed guidance on these principles at hse.gov.uk/coshh/detail/goodpractice.htm.

What Are Employer Duties Under COSHH?

The COSHH regulations place specific duties on employers. Understanding these is essential for compliance.

Regulation 6: Assessment of Health Risks

Employers must assess the risks to health from hazardous substances. This means identifying what hazardous substances are present, who might be exposed and how, evaluating the risks from that exposure, and deciding what controls are needed. Assessments must be suitable and sufficient (thorough enough to identify the risks), recorded (if you have 5 or more employees), and reviewed regularly or when circumstances change.

Regulation 7: Prevention or Control of Exposure

Exposure must be prevented or, where that's not reasonably practicable, adequately controlled. Adequate control means keeping exposure below Workplace Exposure Limits (WELs) where they exist, and as low as reasonably practicable in all cases. Carcinogens, mutagens, and asthmagens have stricter requirements.

Regulation 8: Use of Control Measures

Employers must ensure that control measures, including PPE, are properly used. Employees must use controls as instructed and report any defects. This creates a shared responsibility for maintaining safe conditions.

Regulation 9: Maintenance of Control Measures

All control measures must be maintained in efficient working order. Engineering controls like local exhaust ventilation (LEV) must be examined and tested at least every 14 months. Records of examinations and tests must be kept for at least 5 years.

Regulation 10: Monitoring Exposure

Where required (for certain substances or processes), employers must monitor employee exposure. Records must be kept for 40 years if they could be used to identify individual workers' exposure.

Regulation 11: Health Surveillance

Health surveillance is required where there's a reasonable likelihood of disease or ill health developing, valid techniques are available to detect it, and surveillance will benefit employees. Common examples include skin checks for cement workers, lung function tests for workers exposed to respiratory sensitisers, and audiometry for noise exposure (under separate regulations).

Regulation 12: Information, Instruction and Training

Employees must be given suitable and sufficient information, instruction, and training about the hazards and risks, the findings of risk assessments, the control measures in place, the results of monitoring and health surveillance, and emergency procedures.

The full duties are set out in Regulation 7 of the COSHH Regulations.

The 10 Golden Rules of COSHH Compliance

These practical rules help workers stay safe when handling hazardous substances. They should form the basis of site inductions and toolbox talks.

1. Labels Must Be Legible

Never use a container if you can't read what's in it. Faded, damaged, or missing labels mean unknown hazards. Replace or re-label immediately.

2. Use the PPE Provided

If PPE has been specified for a task, wear it. It's there because other controls aren't sufficient to protect you without it.

3. Never Mix Hazardous Substances

Unless specifically authorised, never combine chemicals. Mixing can create toxic gases, violent reactions, or new hazards.

4. Never Use Unmarked Containers

Every container must be clearly labelled. Decanting into unlabelled bottles is a common cause of accidents and poisonings.

5. Use Dedicated Containers

Hazardous substances should be stored in appropriate containers designed for that purpose. Never use food or drink containers.

6. Know First Aid and Emergency Measures

Before starting work, know what to do if something goes wrong. Where are the eyewash stations? Who are the first aiders? What are the spill procedures?

7. Store Substances Safely

Follow storage requirements. Keep incompatible substances separated. Maintain ventilation. Secure against unauthorised access.

8. Report Damage, Defects and Spillages Immediately

Don't ignore problems. Leaking containers, damaged extraction systems, and spills need immediate attention. Report them.

9. Follow Workplace Procedures

Your employer has set procedures for a reason. Follow them, even when they seem inconvenient. They exist to protect you.

10. Dispose of Hazardous Substances Correctly

Never pour chemicals down drains or put them in general waste. Follow the disposal procedures for each substance. Improper disposal is illegal and dangerous.

How to Conduct a COSHH Risk Assessment: Step-by-Step

A COSHH assessment is a systematic process to identify hazards and decide on controls. Here's how to do it properly.

Step 1: Identify Hazardous Substances

Start by listing all hazardous substances in your workplace. Check product labels for hazard pictograms and warning phrases. Obtain Safety Data Sheets (SDS) from suppliers, as these provide detailed hazard information. Don't forget substances created by work: dusts, fumes, vapours. Consider biological agents if relevant.

Step 2: Identify Who Might Be Harmed and How

For each substance, consider who could be exposed. This includes workers doing the task directly, other workers nearby, contractors and visitors, and the public (if exposure could occur outside the workplace). Then identify the routes of exposure. Is it primarily inhalation, skin contact, or both? How does exposure occur: during mixing, application, cleaning up?

Step 3: Evaluate the Risks and Decide on Precautions

Consider the hazard (how harmful is the substance?), the exposure (how much exposure occurs, for how long, how often?), and existing controls (what's already in place, is it working?). Then apply the hierarchy of controls: can you eliminate or substitute? If not, what engineering controls are possible? Only after exhausting higher-level controls should you rely on PPE.

Step 4: Record Your Findings and Implement Controls

If you have 5 or more employees, you must record your assessment in writing. Even if you don't, a written record is good practice. Record: the hazardous substances identified, who is at risk and how, the control measures in place, any additional controls needed, and who is responsible for implementing them.

Step 5: Review and Update Regularly

COSHH assessments aren't one-off documents. Review them when there's reason to suspect they're no longer valid, after any incident or near-miss, when work processes change, when new substances are introduced, and at least annually as good practice.

Construction Example: COSHH Assessment for Concrete Cutting

A concrete cutting operation would identify silica dust as the primary hazard, with inhalation as the main exposure route. Workers and anyone nearby are at risk. Current controls might include water suppression on the cutter. The assessment would evaluate whether this is sufficient or whether additional controls (on-tool extraction, RPE, enclosure) are needed. The assessment would be documented and reviewed before each project.

Understanding COSHH Hazard Symbols

Hazardous substances are identified by standardised pictograms under the Globally Harmonized System (GHS), implemented in the UK through the CLP Regulations. These red diamond symbols replaced the older orange square symbols.

The nine current pictograms are: Exploding Bomb (explosive substances), Flame (flammable substances), Flame Over Circle (oxidising substances), Gas Cylinder (gases under pressure), Corrosion (corrosive to skin or metals), Skull and Crossbones (acute toxicity, fatal or toxic), Exclamation Mark (harmful, irritant, or sensitiser), Health Hazard (serious health effects like cancer or respiratory sensitisation), and Environment (hazardous to aquatic environment).

Labels also include hazard statements (H-phrases) describing the nature of the hazard, and precautionary statements (P-phrases) describing how to handle safely. Always read the full label, not just the pictogram.

COSHH in the Construction Industry

Construction presents unique COSHH challenges. Work is often temporary, conditions change daily, and multiple trades work in close proximity. This section addresses construction-specific requirements.

Common Construction Hazards

Silica dust is perhaps the biggest COSHH concern in construction. Cutting, grinding, and drilling concrete, bricks, and stone releases respirable crystalline silica (RCS), which causes silicosis, an incurable lung disease, and lung cancer. The HSE estimates that over 500 construction workers die each year from silica-related diseases.

Wood dust is another significant hazard. Hardwood dusts are classified as carcinogenic, causing nasal cancer. Even softwood dust causes asthma and respiratory irritation. Any process that creates wood dust, from sawing to sanding, needs controls.

Cement and concrete products cause both respiratory problems (from dust) and serious skin problems. 'Cement burns' are actually alkaline burns that can cause permanent scarring. Chromates in cement also cause allergic dermatitis.

Welding fumes contain a cocktail of metals and gases. Metal fume fever, respiratory problems, and cancer are all linked to welding exposure. Controls depend on the metals being welded and the environment.

Isocyanates in two-pack paints, foams, and adhesives are potent respiratory sensitisers. Once sensitised, workers can have severe asthma attacks from tiny exposures. Prevention is critical because sensitisation is irreversible.

Construction-Specific Controls

On-tool extraction captures dust at source before it becomes airborne. Water suppression reduces dust when cutting or grinding. Local exhaust ventilation (LEV) removes contaminated air from the breathing zone. Respiratory protective equipment (RPE) is often needed as a backup.

For construction workers exposed to silica, health surveillance including lung function testing may be required. This helps detect early signs of disease when intervention might help.

The HSE provides specific guidance on construction dust at hse.gov.uk/lung-disease/silicosis.htm.

What Are the Penalties for COSHH Non-Compliance?

Failing to comply with COSHH can have severe consequences for businesses and individuals.

HSE Enforcement

The Health and Safety Executive can issue improvement notices (requiring you to fix problems within a set time), prohibition notices (stopping dangerous work immediately), and prosecution for serious breaches.

Criminal Penalties

COSHH breaches are criminal offences. In the magistrates' court, fines are unlimited for most offences. In the Crown Court, fines are unlimited and individuals can face up to 2 years' imprisonment for certain offences. Directors and managers can be personally prosecuted if they consented to or connived in the offence.

Civil Liability

Workers who develop occupational disease due to COSHH failures can claim compensation. Mesothelioma claims alone regularly result in six-figure settlements. Occupational asthma, dermatitis, and other conditions all give rise to claims.

Reputational Damage

HSE prosecutions are public record. Principal contractors increasingly scrutinise subcontractors' health and safety records. A prosecution can mean losing contracts and struggling to win new work.

Frequently Asked Questions About COSHH

What does COSHH stand for?

COSHH stands for Control of Substances Hazardous to Health. It refers to the regulations that require employers to control exposure to hazardous substances to prevent ill health.

What year were COSHH regulations introduced?

The original COSHH regulations came into force in 1988. The current version, which most people refer to, is the Control of Substances Hazardous to Health Regulations 2002, which has been amended several times since.

What are the 8 principles of COSHH?

The 8 principles are: design processes to minimise emissions, take account of all exposure routes, control exposure proportionately, choose effective controls, provide PPE where needed, check and review controls, provide information and training, and ensure controls are used and maintained.

What are the 10 golden rules of COSHH?

The 10 golden rules are: keep labels legible, use PPE provided, never mix chemicals, never use unmarked containers, use dedicated containers, know emergency procedures, store safely, report problems, follow procedures, and dispose correctly.

What substances are covered by COSHH?

COSHH covers chemicals, products containing chemicals, fumes, dusts, vapours, mists, gases, and biological agents. It does not cover asbestos, lead, or radioactive substances, which have their own regulations.

What is a COSHH assessment?

A COSHH assessment is a risk assessment specifically for hazardous substances. It identifies what hazardous substances are present, who might be harmed, what the risks are, and what controls are needed.

How often should COSHH assessments be reviewed?

COSHH assessments should be reviewed when circumstances change, after incidents, when new information becomes available, and regularly (at least annually) as good practice.

Who is responsible for COSHH in the workplace?

Employers have the primary duty to assess and control risks from hazardous substances. Employees must use controls properly and report problems. Self-employed people have duties too.

Summary: Staying COSHH Compliant

COSHH compliance isn't just about avoiding fines. It's about preventing occupational disease that could devastate workers' lives. The regulations provide a clear framework: assess the risks, implement proportionate controls, and keep checking that they work.

For construction businesses, the key challenges are silica dust, wood dust, cement, and the constantly changing work environment. Meeting these challenges requires robust risk assessments that are actually used on site.

Creating comprehensive COSHH assessments manually is time-consuming and often results in generic documents that don't reflect real site conditions. Modern tools can help, generating task-specific assessments that cite the right legislation and identify the right controls automatically.

SwiftRMS generates COSHH-compliant risk assessments in minutes, with automatic hazard identification and control recommendations tailored to construction. Try it free and see how much time you can save while improving your compliance.