COSHH Regulations 2002: What UK Employers Must Do

The Control of Substances Hazardous to Health Regulations 2002, usually called COSHH, require employers to assess and adequately control risks to health from hazardous substances used or produced at work. The practical duties include prevention or control of exposure, maintenance of controls, monitoring or health surveillance where required, worker information and emergency arrangements. This article provides general guidance rather than legal or medical advice.

What are the COSHH Regulations 2002?

The COSHH Regulations 2002 are the main Great Britain regulations for protecting people at work from substances that can harm health. They apply to employers and place related duties on self-employed people and employees.

The Health and Safety Executive's COSHH overview explains that employers must plan, manage and monitor substances hazardous to health. The regulations came into force in 2002 and have been amended, so employers should use current legislation and HSE guidance.

COSHH is built around a simple principle: understand how the work could expose people, prevent exposure where reasonably practicable, and otherwise control it adequately.

Which substances are covered by COSHH?

COSHH covers substances that can harm health because of their hazardous properties or the way they are used or produced at work. It is wider than packaged chemicals carrying a hazard pictogram.

Examples include:

• Chemical products such as cleaners, adhesives, paints and laboratory reagents
• Dusts created by cutting, sanding, grinding or handling powders
• Fumes from welding, soldering and hot processes
• Vapours, mists, gases and aerosols
• Biological agents and harmful micro-organisms
• Substances with a Workplace Exposure Limit
• Materials that create a health risk because of their chemical or toxicological properties and workplace use

Lead and asbestos are not dealt with under COSHH because they have their own specific regulations. Radioactive substances and some other hazards may also be subject to separate or additional regimes.

A product can create several types of duty. A flammable solvent may need a COSHH assessment for harmful exposure and a DSEAR assessment for fire or explosion risk.

What must UK employers do under COSHH?

Employers must assess the risks, prevent or adequately control exposure, and manage the measures needed to keep people protected. The assessment is the starting point, not the final duty.

The main responsibilities can be summarised as follows:

The COSHH Regulations on legislation.gov.uk provide the legal text. HSE guidance translates those duties into practical expectations.

What makes a COSHH assessment suitable and sufficient?

A suitable and sufficient COSHH assessment evaluates the real work rather than simply restating the SDS. It should be detailed enough to identify the measures needed to comply with COSHH.

The assessment should consider:

• The hazardous properties of each substance
• Information supplied by the manufacturer or supplier
• The task, process and work environment
• How much is used or generated
• How often the work occurs and how long it lasts
• Exposure by inhalation, skin or eye contact, ingestion or accidental injection
• Employees, contractors and other people who may be exposed
• People who may be particularly vulnerable
• Existing controls and evidence that they work
• Workplace Exposure Limits where they apply
• Cleaning, maintenance, spills, breakdowns and other non-routine work
• Combined exposure to more than one substance
• Waste, storage and disposal arrangements

The assessment should lead to clear decisions. It should state what workers must do, which controls are essential, how those controls are checked and what action is required if they fail.

How should exposure be prevented or controlled?

Employers should first consider preventing exposure and then apply a hierarchy of controls where prevention is not reasonably practicable. Starting with gloves or respirators skips more reliable options.

HSE's COSHH control guidance recommends asking whether the hazardous substance can be avoided, replaced with a safer product, or used in a safer form or process.

A practical order is:

1. Eliminate the hazardous substance or activity where reasonably practicable.
2. Substitute a safer substance, concentration, form or process.
3. Enclose the process or automate transfer.
4. Control exposure at source using suitable local exhaust ventilation or other engineering measures.
5. Reduce the number of people exposed and the duration or frequency of exposure.
6. Use safe systems of work, training, hygiene and supervision.
7. Provide suitable personal protective equipment for residual risk.

PPE must be selected for the substance, route, task and wearer. It should not be used as the only control where exposure can be controlled more effectively at source.

What does adequate control mean under COSHH?

Adequate control means that controls are effective, exposure is below any applicable Workplace Exposure Limit, and additional requirements for certain serious health hazards are met. A limit is not a target to work up to.

Workplace Exposure Limits are concentrations of hazardous substances in air averaged over a specified period. HSE publishes the current Great Britain limits in EH40. Many substances do not have a WEL, so the absence of a limit does not mean exposure is safe.

For carcinogens, mutagens and asthmagens, HSE states that exposure must be reduced to as low as is reasonably practicable. Employers should also check substance-specific COSHH provisions and applicable approved guidance.

Evidence of adequate control may include:

• Direct observation of the task
• Commissioning and examination records for local exhaust ventilation
• Exposure-monitoring results where monitoring is needed
• Fit testing and maintenance records for respiratory protection
• Worker feedback, health-surveillance outcomes and incident reports
• Inspection and maintenance records

Is a Safety Data Sheet a COSHH assessment?

A Safety Data Sheet is an important source of hazard and control information, but it is not a COSHH assessment. HSE makes this distinction explicit in its Safety Data Sheet guidance.

The SDS cannot know the quantity used, whether the product is sprayed or brushed, the room ventilation, duration of exposure, other substances present or the competence of workers. Those workplace details determine risk.

A strong process uses the SDS to identify hazards, exposure controls, physical properties, reactivity and emergency information, then applies that evidence to the task. Safe Foundry's SDS-to-COSHH workflow is designed around that distinction, with the responsible person reviewing the assessment against real conditions.

When are monitoring and health surveillance required?

Exposure monitoring and health surveillance are required only where the COSHH conditions for them are met, so they should follow a competent assessment. They are not interchangeable.

Exposure monitoring measures the substance in the workplace or the air a worker breathes. It may be necessary where there could be serious health effects, where a WEL could be exceeded, or where measurement is needed to show that controls remain adequate.

Health surveillance is a system of ongoing health checks for workers exposed to particular health risks. It may be appropriate where there is an identifiable disease or adverse effect linked to the exposure, a reasonable likelihood that it may occur under the work conditions, and valid techniques for detecting indications of it.

Occupational health professionals should handle confidential medical information. The employer's health record is different from the clinician's medical record.

What information and training must workers receive?

Workers need information, instruction and training that enables them to understand the hazards and use the controls correctly. Handing someone an SDS without explaining the task is not enough.

Training should cover:

• The substances and activities that can cause harm
• Important findings from the COSHH assessment
• Relevant WELs and warning signs of control failure
• How engineering controls and PPE should be used
• Required checks, cleaning and storage
• Spill, exposure and emergency procedures
• Defect and incident reporting
• Where assessments and SDS can be found

Contractors also need relevant information about hazards and controls, while the employer needs to understand substances that contractors bring onto the premises.

The chemical-safety features page shows how documents and assessments can be organised, and the help centre provides product guidance for maintaining those records.

When must a COSHH assessment be recorded and reviewed?

Employers with five or more employees must record the significant findings of their COSHH assessment. Smaller employers must still assess and control the risks, and a written record is usually useful evidence of the decisions made.

Record:

• The hazards and people who may be affected
• The tasks and exposure routes assessed
• Existing and required controls
• Actions, owners and completion dates
• Monitoring or health-surveillance decisions where relevant
• Information and training requirements
• Emergency arrangements
• Review triggers and review date

Review the assessment regularly and whenever there is reason to believe it is no longer valid. Changes to staff, substances, equipment, quantities, processes or workplace layout can create new risks. Incidents, near misses, worker concerns, monitoring results or evidence of poor control should also trigger review.

What is a practical COSHH compliance cycle?

COSHH works best as a repeated management cycle rather than a folder of completed forms. The cycle is:

1. Maintain an accurate inventory of substances and current SDS.
2. Prioritise activities with potential for significant exposure.
3. Complete suitable, task-specific assessments.
4. Implement prevention and control measures.
5. Inform and train the people doing the work.
6. Inspect, maintain and test controls.
7. Monitor exposure or health where required.
8. Review evidence, changes, incidents and overdue actions.

The purpose of COSHH paperwork is to support effective control. A well-written assessment is valuable only when it matches the work, is understood by workers and is kept current.