The Control of Substances Hazardous to Health Regulations 2002 (COSHH) are the main UK regulations controlling workplace exposure to hazardous substances. They require employers to assess the risks from hazardous substances and put in place adequate control measures to protect employees and others who may be exposed. COSHH applies to nearly every workplace in Great Britain — from construction sites and factories to hair salons, care homes and offices.
COSHH compliance is mandatory, and enforcement is strict. Failure to carry out COSHH assessments is one of the most frequently prosecuted health and safety offences. This guide explains what COSHH requires, who it applies to, and what you need to do to comply.
What COSHH 2002 Requires
The Control of Substances Hazardous to Health Regulations 2002 (as amended) set out eight core duties for employers and the self-employed. These duties apply whenever work involves substances that could cause harm to health. The regulations were updated most recently in 2013 to implement changes to chemical classification under the CLP Regulation.
Under Regulation 6, employers must carry out a suitable and sufficient assessment of the risks from hazardous substances before work begins. The assessment must identify: the hazardous substances present; the nature and level of exposure; who may be affected; what control measures are needed; and whether further action is required. The assessment must be recorded in writing if the employer has five or more employees, but HSE guidance recommends written assessments in all cases.
Regulation 7 requires employers to prevent exposure to hazardous substances, or where prevention is not reasonably practicable, to control exposure adequately. Control measures must follow the hierarchy of control: elimination or substitution first, then engineering controls such as local exhaust ventilation (LEV), then safe systems of work, and only as a last resort, personal protective equipment (PPE). Control measures must be properly maintained, examined and tested under Regulation 9 — for example, LEV systems must be thoroughly examined and tested at least every 14 months.
Regulation 10 requires employers to monitor exposure where necessary to protect health. This might include air monitoring, biological monitoring, or health surveillance. Regulation 11 requires health surveillance where employees are exposed to substances specified in Schedule 6 (such as vinyl chloride monomer, compressed air, or certain biological agents), or where a risk to health is identified by the COSHH assessment and valid surveillance techniques exist. Records of health surveillance must be kept for at least 40 years.
Under Regulation 12, employers must provide employees with suitable and sufficient information, instruction and training about the hazardous substances they work with, the risks, and the control measures. This must be repeated periodically and whenever there is a change in exposure. Employees must also be informed of the results of any exposure monitoring or health surveillance that relates to them.
Who COSHH Applies To
COSHH 2002 applies to all employers in Great Britain, regardless of size or sector. Self-employed individuals who work with hazardous substances must also comply. The regulations cover employees, contractors, temporary workers, and anyone else who may be exposed — including visitors, clients and members of the public.
Industries and sectors commonly affected by COSHH include:
- Construction — exposure to silica dust, cement, solvents, adhesives, bitumen, welding fumes, lead paint and asbestos
- Manufacturing — chemicals, resins, coatings, cleaning agents, metal working fluids, and process fumes
- Healthcare and laboratories — biological agents, disinfectants, sterilising agents, cytotoxic drugs and anaesthetic gases
- Agriculture — pesticides, veterinary medicines, grain dust, animal waste and biological agents
- Cleaning — detergents, bleach, degreasers, drain cleaners and disinfectants
- Motor vehicle repair — brake dust, exhaust fumes, solvents, paints, oils and degreasers
- Hair and beauty — hair dyes, bleaches, perming solutions, nail products and aerosols
- Printing — inks, solvents, cleaning fluids and paper dust
- Catering — cleaning chemicals, oven cleaners and disinfectants
COSHH does not apply to asbestos (covered by the Control of Asbestos Regulations 2012), lead (covered by the Control of Lead at Work Regulations 2002), or radioactive substances. However, employers working in those areas still have general duties under the Health and Safety at Work etc. Act 1974.
Key COSHH Duties at a Glance
- Regulation 6: Carry out a suitable and sufficient COSHH assessment before employees are exposed to hazardous substances. Identify the substances, assess the risks, determine control measures, and record the assessment in writing.
- Regulation 7: Prevent or adequately control exposure to hazardous substances by applying the hierarchy of control — eliminate, substitute, enclose, use engineering controls, implement safe systems, and provide PPE only as a last resort.
- Regulation 8: Ensure control measures are used, maintained and operate correctly. Provide instruction and training so employees understand how to use controls properly.
- Regulation 9: Maintain, examine and test control measures. LEV systems must be examined and tested at least every 14 months by a competent person, with records kept for at least five years.
- Regulation 10: Monitor exposure where necessary to protect health. Air monitoring, surface sampling or biological monitoring may be required depending on the substance and level of risk.
- Regulation 11: Provide health surveillance where required by Schedule 6 or where the COSHH assessment identifies a risk to health and valid surveillance techniques exist. Keep records for at least 40 years.
- Regulation 12: Provide information, instruction and training to employees about the hazardous substances, the risks, control measures and emergency procedures. Repeat training regularly and when work changes.
- Regulation 13: Make arrangements to deal with accidents, incidents and emergencies involving hazardous substances. This includes having appropriate first aid, spill kits, emergency procedures and ensuring employees know what to do.
Penalties for Non-Compliance with COSHH
COSHH 2002 is enforced by the Health and Safety Executive (HSE) and local authority environmental health officers. Breaches are criminal offences prosecuted under the Health and Safety at Work etc. Act 1974. In the Crown Court, fines are unlimited and individuals can be imprisoned for up to two years. In the Magistrates Court, the maximum fine is £20,000 per offence.
The HSE can issue improvement notices requiring specific action within a set timeframe, and prohibition notices that stop work immediately until the breach is remedied. Under the Fee for Intervention (FFI) scheme, the HSE charges £163 per hour for time spent investigating and taking enforcement action for material breaches. A single inspector visit for a missing COSHH assessment or inadequate controls can cost several hundred pounds in FFI charges alone, even without prosecution.
Between 2019 and 2023, the HSE reported that exposure to hazardous substances remains one of the leading causes of work-related ill health in Great Britain. Occupational lung disease, occupational cancer and dermatitis collectively affect tens of thousands of workers each year. Many of these cases result from failure to assess and control exposure under COSHH. Prosecutions for COSHH breaches regularly result in five-figure fines, particularly where exposure leads to serious injury or disease.
How COSHH Relates to Risk Assessments
A COSHH assessment is a specific type of risk assessment required under Regulation 6 of COSHH 2002. It sits alongside the general workplace risk assessment required under Regulation 3 of the Management of Health and Safety at Work Regulations 1999. Both are legal requirements, and both must be recorded in writing.
The COSHH assessment focuses specifically on the hazardous substances used, stored or created by the work. It must answer: What substances are involved? What are the health hazards? Who might be exposed and how? What control measures are in place? Are they adequate? What further action is needed? The assessment must consider all routes of exposure — inhalation, skin contact, ingestion and injection — and all groups of people at risk, including employees, contractors, cleaners, maintenance staff and visitors.
For businesses using multiple hazardous substances, a separate COSHH assessment should be completed for each substance or process. For straightforward low-risk activities — such as occasional use of standard cleaning products in small quantities — a generic assessment may be sufficient. For higher-risk work — such as spray painting, welding, working with solvents or exposure to respirable crystalline silica — a detailed site-specific assessment is required.
A compliant COSHH assessment must lead to action. If the assessment identifies that current controls are inadequate, the employer must implement additional control measures. If monitoring or health surveillance is needed, it must be arranged. The assessment is not a tick-box exercise — it is the foundation of a safe system of work. Need a COSHH risk assessment for your workplace? Anyrisks generates compliant COSHH assessments in under 2 minutes, covering the substances you use, exposure routes, control measures and PPE requirements.
COSHH and the Construction Industry
Construction is one of the highest-risk sectors for exposure to hazardous substances. Silica dust from cutting, grinding or drilling concrete, brick, stone or mortar is a major hazard. Respirable crystalline silica (RCS) causes silicosis, chronic obstructive pulmonary disease (COPD) and lung cancer. The HSE estimates that over 500 construction workers die each year from past exposure to silica dust.
Under COSHH, construction employers must assess the risk from silica dust and implement controls to prevent or adequately control exposure. This typically includes: using water suppression or on-tool extraction when cutting or grinding; ensuring LEV equipment is properly maintained and tested; providing RPE (respiratory protective equipment) where engineering controls are not sufficient; and implementing strict cleaning regimes to prevent dust accumulation. Dry sweeping and compressed airline to blow down dust are prohibited.
Other common COSHH hazards in construction include: cement and wet concrete (causing dermatitis and chemical burns); solvents in paints, adhesives and cleaning products (causing dizziness, headaches and long-term neurological damage); welding fumes (causing metal fume fever, lung damage and cancer); bitumen and coal tar (causing skin cancer and respiratory harm); and wood dust (a known carcinogen). All require COSHH assessment and adequate controls before work starts.
Construction businesses must also consider COSHH in the context of the Construction (Design and Management) Regulations 2015. The construction phase plan must address how hazardous substances will be managed, and contractors must provide COSHH assessments to the principal contractor. For more on CDM compliance, see our CDM Regulations 2015 guide.
COSHH and Small Businesses
Many small businesses assume COSHH does not apply to them because they only use common cleaning products or small quantities of chemicals. That assumption is wrong. COSHH applies to all employers regardless of size. Even a small office using multipurpose cleaner, glass cleaner and hand sanitiser is using hazardous substances and must assess the risks.
For low-risk, straightforward activities, the assessment does not need to be complex. The HSE provides a simple risk assessment template (COSHH essentials) that small employers can use. The key steps are: list the hazardous substances you use; check the safety data sheet (SDS) for each substance; identify who might be exposed and how; confirm that the control measures already in place (such as using products as directed, storing them securely, and providing PPE where needed) are adequate; and record your findings.
Common mistakes made by small businesses include: failing to obtain safety data sheets from suppliers; not reading or understanding the hazard information; using products incorrectly (for example, mixing bleach with acidic cleaners, which creates toxic chlorine gas); not providing adequate ventilation; and failing to train staff on safe use. These errors can result in chemical burns, respiratory harm, and poisoning — all preventable with a basic COSHH assessment.
COSHH Assessments and Safety Data Sheets
Every hazardous substance must be supplied with a safety data sheet (SDS), previously known as a material safety data sheet (MSDS). The SDS is a legal document that provides detailed information about the substance, including: hazard classification; first aid measures; fire-fighting measures; handling and storage requirements; exposure controls and PPE; physical and chemical properties; and toxicological information.
Under COSHH Regulation 12, the SDS is the primary source of information for your COSHH assessment. Employers must request an SDS from the supplier for every hazardous product used. If a supplier refuses to provide an SDS, the product should not be used. The SDS must be kept accessible to employees and reviewed as part of the COSHH assessment.
Section 8 of the SDS lists the workplace exposure limits (WELs) and recommended control measures. If the substance has a WEL, exposure must be controlled below that limit. If no WEL is assigned, exposure must be reduced to as low as reasonably practicable. The SDS should also specify the PPE required — but remember, PPE is the control of last resort under Regulation 7. If the SDS recommends PPE, the COSHH assessment must first consider whether higher controls such as substitution, enclosure or ventilation are feasible.
Health Surveillance Under COSHH
Regulation 11 of COSHH 2002 requires health surveillance where: the employee is exposed to a substance listed in Schedule 6 (such as vinyl chloride monomer or work in compressed air); or the COSHH assessment identifies a risk to health and there are valid techniques available to detect early signs of disease. Health surveillance aims to detect adverse health effects at an early stage so that action can be taken to prevent further harm.
Common examples of health surveillance in practice include: respiratory questionnaires and spirometry (lung function tests) for workers exposed to respiratory sensitisers such as isocyanates or flour dust; skin checks for workers handling chromates, epoxy resins or cutting oils; and biological monitoring for workers exposed to lead or solvents. The type and frequency of surveillance must be appropriate to the level and nature of exposure.
Health surveillance must be carried out by a qualified person — typically an occupational health nurse or doctor. Records must be kept for at least 40 years and must include: the employee's name; details of the health surveillance carried out; the date; and the conclusions. Employees must be informed of the results and any action needed. If health surveillance shows that control measures are inadequate, the employer must review the COSHH assessment immediately and implement additional controls.
COSHH Compliance Checklist
To comply with COSHH 2002, employers must:
- Identify all hazardous substances used, stored or created by the work
- Obtain and review safety data sheets for every hazardous substance
- Carry out a COSHH assessment for each substance or process, assessing the risks and determining adequate control measures
- Record the assessment in writing and make it accessible to employees
- Implement the hierarchy of control: eliminate or substitute first, then use engineering controls, safe systems and PPE only as a last resort
- Ensure control measures are used correctly — provide instruction, training and supervision
- Maintain, examine and test control measures regularly (LEV systems every 14 months, RPE fit testing, PPE inspection)
- Monitor exposure where necessary to protect health
- Provide health surveillance where required
- Provide information, instruction and training to all employees on the hazards, risks, controls and emergency procedures
- Make arrangements for accidents, incidents and emergencies
- Review COSHH assessments regularly (at least annually) and whenever there is significant change
For businesses needing a compliant written assessment, Anyrisks generates COSHH risk assessments covering the substances you use, the exposure routes, the control measures required, and the PPE needed — in under 2 minutes, delivered as PDF and editable Word doc.
