Helping you understand your COSHH Risk Assessment

Inform workers about COSHH Risk Assessments: Protecting People from Harmful Substances at Work

Almost every workplace uses hazardous substances —whether it’s dust from wood cutting, cleaning chemicals, fumes from welding, or vapours from paints and solvents. These substances pose serious health risks if not properly controlled. That’s where the COSHH Risk Assessment comes in. It is a legal requirement in the UK and a key part of managing workplace health and safety.

COSHH stands for the Control of Substances Hazardous to Health Regulations 2002. These regulations require employers to identify hazardous substances, assess the risks they pose to health, and implement control measures to eliminate or reduce exposure. The COSHH risk assessment forms the foundation of this entire process.

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COSHH Compliance

What Is a COSHH Risk Assessment?

A COSHH risk assessment systematically identifies hazardous substances in the workplace, evaluates the health risks associated with them, and determines appropriate measures to control those risks.

It answers key questions:

  • What hazardous substances are present?
  • Who is exposed, and how?
  • What health risks does the work involve?
  • Are existing controls adequate?
  • What further steps do I need to reduce the risk?

Particle Counting Workplace Air Survey

Why COSHH Risk Assessments Matter

  • Legal Compliance

    Under the COSHH Regulations, employers must assess the risks to health from exposure to hazardous substances. Failure to comply can lead to enforcement action, fines, or prosecution by the Health and Safety Executive (HSE).

  • Protecting Health

    Many hazardous substances cause serious health problems, including respiratory diseases (like asthma and silicosis), skin conditions (like dermatitis), and long-term illnesses such as cancer. COSHH risk assessments help identify and mitigate these risks.

  • Promoting a Safe Working Environment

    Proper assessments lead to safer working practices, increased awareness among staff, and a culture of prevention. They also help reduce accidents, absenteeism, and long-term health claims.

  • Operational Efficiency

    Understanding how workers use and store substances, and where the risks lie, improves process control and reduces waste or contamination.

What Substances Fall Under COSHH?

COSHH covers a wide range of hazardous substances, including:

  • Chemicals and products containing chemicals (e.g., cleaning agents, adhesives)
  • Fumes (e.g., from welding or soldering)
  • Dusts (e.g., wood dust, flour dust, silica)
  • Vapours and gases (e.g., solvents, chlorine)
  • Biological agents (e.g., bacteria, viruses, fungi)
  • Nanomaterials and substances generated during work activities (e.g., diesel exhaust)

Asbestos, lead, and radioactive substances have separate regulations, but COSHH principles may still apply.

link to wood dust air monitoring page

Step-by-Step Guide to Conducting a COSHH Risk Assessment

  • Identify the Hazardous Substances

    Create an inventory of all substances used or generated in work processes. Review:

    • Safety Data Sheets (SDS)
    • Product labels
    • Process flow diagrams
    • Reports of previous incidents or illnesses

    Account for substances produced by work activities (e.g., dust, fumes) and those present in raw materials.

  • Assess the Risks

    Evaluate how substances cause harm:

    • What are the routes of exposure? (inhalation, skin contact, ingestion)
    • Who might be exposed? (operators, maintenance staff, cleaners, visitors)
    • How often and for how long does exposure occur?
    • Are there vulnerable groups? (pregnant workers, young people, asthmatics)

    Use workplace exposure limits (WELs) from the HSE as reference points and consider cumulative and combined effects of multiple substances.

  • Decide on Precautions

    Identify existing control measures, such as local exhaust ventilation (LEV), PPE, or closed systems, and assess their adequacy. If controls are insufficient, ask yourself:

    • Substitution: Can we use a less hazardous substance?
    • Process change: Can we modify a substance to reduce exposure?
    • Engineering controls: Can containment or ventilation improve?
    • Administrative controls: Can we limit access, improve training, or implement staff rotation?

    Use personal protective equipment (PPE) only as a last resort.

  • Record the Assessment

    Employers with five or more employees must document the assessment. Even in smaller businesses, recording findings is best practice.

    A comprehensive COSHH assessment should include:

    • Identified hazardous substances
    • The nature and level of risk
    • Existing control measures
    • Additional measures required
    • Responsible persons for implementation
    • The date of the next review

  • Implement Control Measures

    Ensure the improvements you identify are put into practice. This may include:

    • Installing or upgrading LEV systems
    • Changing work procedures
    • Providing training or PPE
    • Setting up health surveillance if necessary

    Inform Staff about risks and protective measures.

  • Monitor and Review

    COSHH assessments require regular reviews, especially when:

    • Processes or substances change
    • New hazards emerge
    • Control measures fail or prove inadequate
    • Incidents or health issues arise

    Frequent reviews ensure assessments remain current and effective.

Common Mistakes to Avoid

  • Generic Assessments: COSHH assessments must be specific to the workplace and processes, not copied from templates.
  • Over-reliance on PPE: PPE should be a last resort after you have considered all other controls.
  • Ignoring Generated Substances: Many risks stem from substances created during work processes, not just those in containers.
  • Inadequate Communication: Employees must understand the risks and controls, not just have them documented.
  • Lack of Follow-Up: Control measures must be implemented and monitored for effectiveness.

COSHH Risk Assessment vs General Risk Assessment

A general workplace risk assessment covers slips, trips, machinery, and manual handling, while a COSHH risk assessment focuses solely on hazardous substances. It requires expertise in chemical properties, health effects, and control strategies.

Depending on complexity, input from occupational hygienists, safety consultants, or health professionals may be necessary.

Useful Tools and Resources

  • HSE Website (www.hse.gov.uk) – Extensive COSHH guidance and templates.
  • COSHH Essentials – An HSE tool for lower-risk substances and tasks.
  • SDS Sheets – Provided by manufacturers, detailing handling, hazards, and first aid.
  • Occupational Exposure Limits – Check EH40/2005 for current WELs.

Final Thoughts

A well-conducted COSHH risk assessment protects health in environments where hazardous substances are used. It’s not just about compliance; it’s about preventing serious illnesses, improving workplace morale, and prioritizing employee well-being.

By adopting a structured approach, engaging staff, and regularly reviewing assessments, businesses create safer, smarter workplaces. The biggest risks often come not from obvious chemicals but from everyday dusts, fumes, and vapours that silently impact health if not controlled.

Doing COSHH right means doing safety right.