COSHH Risk Assessment: Complete Guide for UK Workplaces

COSHH risk assessments are a legal requirement for any UK workplace that uses, stores, or produces hazardous substances. The Control of Substances Hazardous to Health Regulations 2002 (COSHH) place specific duties on employers to protect workers and others from health risks.

This guide explains everything you need to know about conducting COSHH assessments that satisfy HSE requirements and genuinely protect your workforce.

What is COSHH?

COSHH stands for Control of Substances Hazardous to Health. The COSHH Regulations 2002 require employers to control substances that can harm workers' health. This includes chemicals, fumes, dusts, vapours, mists, nanotechnology, gases, biological agents, and germs that cause diseases.

COSHH covers virtually all substances except asbestos, lead, radioactive materials, and substances below ground in mines—these have their own specific regulations.

What is a COSHH Risk Assessment?

A COSHH risk assessment is a systematic evaluation of health hazards from substances used or created in your workplace. It identifies who might be harmed, evaluates the risks, and determines what control measures are needed to prevent or adequately control exposure.

Unlike general risk assessments, COSHH assessments focus specifically on substance-related health risks. They require you to consider exposure routes (inhalation, skin contact, ingestion), exposure duration and frequency, and the specific health effects of each substance.

Who Needs a COSHH Assessment?

Any employer whose workers may be exposed to hazardous substances must conduct COSHH assessments. This applies across virtually every industry:

• Construction (cement, silica dust, solvents, adhesives)
• Manufacturing (industrial chemicals, process emissions)
• Healthcare (cleaning agents, pharmaceuticals, biological hazards)
• Cleaning services (bleach, degreasers, disinfectants)
• Agriculture (pesticides, fertilisers, animal waste)
• Motor trades (oils, fuels, brake dust, paints)
• Hairdressing and beauty (hair dyes, nail products, aerosols)

Even office environments may need COSHH assessments for printer toner, cleaning products, or correction fluids.

Legal Requirements Under COSHH 2002

The COSHH Regulations place eight specific duties on employers:

1. Assess the risks to health from hazardous substances
2. Prevent or control exposure to hazardous substances
3. Ensure control measures are used and maintained
4. Monitor exposure at the workplace where necessary
5. Carry out health surveillance where appropriate
6. Prepare plans and procedures for accidents, incidents, and emergencies
7. Ensure employees are properly informed, trained, and supervised
8. Review and update assessments regularly

Failure to comply can result in enforcement action, improvement notices, prohibition notices, or prosecution with unlimited fines.

How to Conduct a COSHH Risk Assessment: 5 Steps

Step 1: Identify Hazardous Substances

Start by creating a comprehensive inventory of all hazardous substances in your workplace. Include:

• Substances you buy in (check Safety Data Sheets)
• Substances produced by work processes (fumes, dust, waste)
• Naturally occurring substances (grain dust, bacteria)
• Biological agents (viruses, bacteria, fungi)

Look for hazard pictograms and signal words on product labels. The GHS (Globally Harmonised System) symbols indicate specific hazard types.

Step 2: Decide Who Might Be Harmed and How

Consider all people who might be exposed:

• Workers who directly use hazardous substances
• Workers nearby who may be indirectly exposed
• Maintenance and cleaning staff
• Contractors and visitors
• Members of the public

Pay particular attention to vulnerable groups: young workers, pregnant women, those with pre-existing conditions, and workers with limited English who may not understand warning labels.

Document the exposure routes (inhalation, skin absorption, ingestion, injection) and likely health effects (acute, chronic, sensitisation, cancer).

Step 3: Evaluate the Risks and Existing Controls

For each substance, evaluate:

• How much substance is used or produced
• How often and for how long workers are exposed
• The severity of potential health effects
• Effectiveness of current control measures
• Workplace Exposure Limits (WELs) where applicable

Check Safety Data Sheets (SDS) for each product. Section 8 of the SDS contains exposure limits and recommended control measures.

Step 4: Decide on Control Measures

Apply the hierarchy of control in order of preference:

1. Elimination – Remove the hazardous substance entirely
2. Substitution – Replace with a less hazardous alternative
3. Engineering controls – Enclose the process, use LEV (local exhaust ventilation)
4. Administrative controls – Reduce exposure time, rotate workers, implement safe systems of work
5. PPE – Respiratory protection, gloves, eye protection (last resort)

PPE should never be the primary control measure. It's a last line of defence when other controls cannot adequately reduce exposure.

Step 5: Record, Implement, and Review

Document your assessment including:

• Substances identified and their hazards
• Who is at risk and how
• Risk evaluation findings
• Control measures required and implemented
• Monitoring and health surveillance needs
• Review date

Review your COSHH assessments regularly—at least annually or whenever there are significant changes to processes, substances, or when incidents occur.

Understanding Safety Data Sheets (SDS)

Safety Data Sheets are essential for COSHH assessments. Suppliers must provide an SDS for any hazardous substance. Each SDS contains 16 mandatory sections:

• Section 2: Hazard identification – Classification and labelling
• Section 4: First-aid measures – What to do after exposure
• Section 7: Handling and storage – Safe use precautions
• Section 8: Exposure controls/PPE – WELs and recommended controls
• Section 11: Toxicological information – Health effects data

Keep SDS files accessible and up to date. Suppliers should provide updated versions when formulations or hazard information changes.

Workplace Exposure Limits (WELs)

WELs are UK occupational exposure limits set by HSE. They represent the maximum concentration of an airborne substance averaged over a reference period to which employees may be exposed.

Two types of WEL exist:

• Long-term exposure limit (LTEL) – 8-hour time-weighted average
• Short-term exposure limit (STEL) – 15-minute reference period

Current WELs are published in HSE document EH40. Exposure above a WEL means controls are inadequate and must be improved.

Health Surveillance Requirements

COSHH requires health surveillance when:

• Workers are exposed to substances linked to specific diseases or adverse health effects
• There is a reasonable likelihood of disease or effect occurring
• Valid techniques exist to detect the disease or effect

Schedule 6 of COSHH lists substances requiring health surveillance, including certain lead compounds, crystalline silica, isocyanates, and substances causing occupational asthma.

Health surveillance might include lung function tests (spirometry), skin checks, biological monitoring, or questionnaires.

Common COSHH Assessment Mistakes

Avoid these frequent errors that lead to inadequate assessments:

• Missing substances – Only assessing purchased chemicals while ignoring process-generated substances like welding fumes or wood dust
• Relying solely on PPE – Skipping the hierarchy of control and jumping straight to respirators and gloves
• – Using template assessments without adapting to actual workplace conditions
• Outdated information – Working from old SDS or failing to review when processes change
• Ignoring non-routine work – Forgetting maintenance, cleaning, and emergency scenarios
• No worker involvement – Completing assessments without consulting those who actually work with the substances

COSHH Training Requirements

COSHH Regulation 12 requires employers to provide employees with suitable and sufficient information, instruction, and training. This must include:

• Names and hazards of substances they work with
• Findings of the COSHH risk assessment
• Control measures and why they're important
• How to use control measures and PPE correctly
• Emergency procedures and first aid
• Health surveillance procedures if applicable

Training must be provided before workers are exposed and refreshed regularly, especially when processes or substances change.

How swiftRMS Simplifies COSHH Assessments

Creating comprehensive COSHH assessments manually is time-consuming. swiftRMS uses AI to generate substance-specific assessments that include:

• Automatic hazard identification from substance names
• Appropriate control measures following the hierarchy
• UK-specific legal references and WEL data
• Health surveillance recommendations where needed
• Professional formatting ready for site use

Generate compliant COSHH assessments in minutes rather than hours, giving you more time to focus on implementing effective controls.

Frequently Asked Questions

How often should COSHH assessments be reviewed?

Review annually at minimum, or sooner if there are changes to substances, processes, work methods, or if monitoring or health surveillance shows controls aren't working.

Do I need a separate assessment for each substance?

Not necessarily. You can group substances with similar hazards and uses into a single assessment if the control measures are the same. However, particularly hazardous substances may warrant individual assessments.

What qualifications do I need to conduct COSHH assessments?

COSHH doesn't specify formal qualifications. The person must be competent—having sufficient training, experience, and knowledge of the work activities and substances involved. For complex situations, specialist advice may be needed.

Are household cleaning products covered by COSHH?

Yes, if used in a workplace. Domestic products used professionally (bleach, cleaning sprays) still require COSHH assessment. The concentration, frequency of use, and lack of domestic ventilation may increase workplace risks.

Ready to streamline your COSHH compliance? Try swiftRMS free and generate your first COSHH risk assessment in minutes.