A step-by-step COSHH risk assessment guide based on UK HSE guidance

Understand your duties and implement practical control measures in the workplace

Introduction

The Control of Substances Hazardous to Health (COSHH) Regulations 2002 are a key part of UK health and safety law. They require employers to assess and control the risks associated with hazardous substances used or produced in the workplace.

This guide provides a practical overview of how to carry out a COSHH risk assessment and implement effective control measures. It’s designed for employers, managers, and site supervisors responsible for workplace safety across industries such as construction, manufacturing, warehousing, and waste management.

What Is a COSHH Risk Assessment?

A COSHH assessment identifies substances that may be hazardous to health and outlines how exposure to them can be prevented or controlled. It is a legal requirement for any employer using chemicals or processes that generate dust, fumes, vapours, or other harmful by-products.

When Is a COSHH Assessment Required?

A COSHH assessment is required when:

Hazardous substances are used, produced, or stored
New work processes are introduced
There is potential for exposure through inhalation, skin contact, ingestion, or injection
Employees or contractors are at risk from substances such as cleaning chemicals, solvents, fuels, paints, adhesives, or fine dust

Key Steps in a COSHH Assessment

The Health and Safety Executive (HSE) outlines a straightforward process for managing COSHH risks:

1. Identify Hazardous Substances

Review product labels and Safety Data Sheets (SDS)
Identify harmful by-products generated by work processes (e.g. fumes, dust, mists)

2. Assess the Risks

Who is exposed, how often, and under what conditions?
Consider all tasks including cleaning, maintenance, and accidental contact

3. Decide on Control Measures

Apply the hierarchy of control:

Eliminate or substitute the substance where possible
Use engineering controls such as ventilation or enclosed systems
Apply administrative controls like restricted access and training
Provide personal protective equipment (PPE) as a last resort

4. Record Your Findings

Document your risk assessment clearly and make it accessible to relevant staff
Include the substance, risks identified, controls required, and responsibilities

5. Implement Controls

Provide appropriate PPE (e.g. gloves, goggles, respirators)
Use compliant COSHH and hazard signage to alert workers
Install spill response stations and containment equipment as needed
Train staff in safe handling, emergency response, and PPE use

6. Monitor and Maintain

Inspect PPE, ventilation, signage, and spill kits regularly
Ensure all controls are functioning and up to date

7. Prepare for Emergencies

Provide clear instructions for chemical spills and exposures
Keep SDS documents easily accessible
Ensure spill kits and emergency equipment are in place and visible

8. Review the Assessment

Reassess if substances, processes, or work locations change
Schedule regular reviews to ensure ongoing compliance

COSHH in Practice: Example Scenario

A warehouse operation uses concentrated cleaning chemicals for floor maintenance. Following a COSHH assessment, the site introduced:

Chemical-resistant gloves and eye protection for operatives
Clear signage marking chemical storage and mixing areas
A wall-mounted spill kit with absorbents and PPE
SDS folders kept near the point of use
Routine staff training on safe handling and first response

These measures reduced exposure risk and ensured compliance with COSHH regulations.

Common Pitfalls to Avoid

Relying solely on PPE without considering substitution or engineering controls
Inadequate signage or unlabelled containers
Spill kits that are inaccessible, unstocked, or unfamiliar to staff
Assessments not reviewed after process or product changes