What the Law Says About Legionella Risk Assessments
Legionella risk assessments are not just good practice — they are a legal requirement under UK health and safety law. This page explains the key legislation, approved codes of practice, and your legal duties if you manage a property, workplace, or water system.
Related guides:
Why Do I Need a Legionella Risk Assessment?
Legionella bacteria can thrive in water systems if conditions are right — particularly in stagnant water between 20–45 °C. Inhaling contaminated droplets can cause Legionnaires’ disease, a potentially fatal form of pneumonia.
UK law (under the Health and Safety at Work Act, COSHH, and ACOP L8) requires that all water systems where Legionella could be present must be assessed for risk.
When Do I Need to Carry Out a Legionella Risk Assessment?
You must carry out a risk assessment if you:
- Are an employer or landlord
- Manage a building with hot and cold water systems
- Own a facility with showers, spa pools, cooling towers, or water storage
- Let or manage rental properties
Even simple domestic-style systems in rental or small business premises must be assessed if they include storage tanks, rarely used outlets, or potential for aerosol generation.
Understanding the Legal Framework
In the UK, the legal requirement to control Legionella bacteria is based on several overlapping laws and official guidance documents. These include:
- The Health and Safety at Work etc. Act 1974
- The Control of Substances Hazardous to Health Regulations 2002 (COSHH)
- The Management of Health and Safety at Work Regulations 1999
- The Approved Code of Practice L8 (ACOP L8)
- HSG274 Technical Guidance (Parts 1–3)
The Key Legal Duty: Keep People Safe from Harm
Under Section 2 and 3 of the Health and Safety at Work Act, employers and those in control of premises must ensure that employees and non-employees (e.g. tenants, visitors, contractors) are not exposed to health and safety risks, including exposure to Legionella bacteria.
This duty includes:
- Preventing the creation of hazardous aerosol droplets
- Managing water systems to prevent conditions that support Legionella growth
- Ensuring regular monitoring and maintenance is carried out
What Is ACOP L8 and Why Does It Matter?
If you are prosecuted for a health and safety breach, and it is shown that you did not follow ACOP L8, you will need to prove that you complied with the law in some other way.
ACOP L8 requires dutyholders to:
- Carry out a Legionella risk assessment
- Appoint a competent responsible person
- Create and implement a written scheme of control
- Keep appropriate monitoring and maintenance records
- Review the system regularly or if changes occur
What Does COSHH Say About Legionella?
COSHH regulations apply because Legionella is classified as a biological hazard. COSHH Regulation 6 requires you to assess and control the risk of exposure to harmful substances — including bacteria — in the workplace.
For Legionella, this means:
- Identifying risk factors in water systems
- Implementing control measures (e.g. temperature control, flushing, chemical dosing)
- Ensuring proper documentation and staff training
- Reviewing control measures regularly
Management of Health and Safety at Work Regulations 1999
These regulations place a general duty on employers and those in control of premises to:
- Conduct suitable and sufficient risk assessments
- Appoint competent help
- Provide training, information, and supervision
- Cooperate and coordinate if multiple parties share a building
Who Needs to Comply?
You must comply if you are:
- An employer
- A landlord or letting agent
- A facilities manager
- The owner or operator of a building with water systems
This includes workplaces, offices, warehouses, healthcare settings, residential homes, schools, leisure facilities, and domestic rental properties with features like stored water or communal showers.
What Happens If You Don’t Comply?
Failing to assess and manage the risk of Legionella can lead to:
- Enforcement notices from the HSE or local authority
- Criminal prosecution
- Civil claims for illness or death (including Legionnaires’ disease)
- Damage to your business reputation
Fines can be significant — and in serious cases, individuals can face imprisonment.
Linking Law to Action: What You Should Do
To stay compliant:
- Book a Legionella risk assessment with a qualified assessor
- Appoint a responsible person
- Document your written scheme of control
- Carry out regular monitoring and maintenance
- Keep full records and review annually or after system changes
Need Help with Compliance?
If you’re not sure whether you meet legal requirements, we can help. Our Legionella risk assessment service is trusted by landlords, schools, healthcare providers and SMEs across South Yorkshire.
- ✅ Fully insured
- ✅ City & Guilds qualified
- ✅ Reports from just £80
Book Your Legionella Risk Assessment Now
Serving Doncaster and Surrounding Areas
Based in Doncaster, we provide fast, reliable Legionella assessments for properties in South Yorkshire and the surrounding region. Whether you manage a small office or a multi-site property portfolio, we’ll help you stay compliant and protect the people in your care.
FAQs
Is a Legionella risk assessment a legal requirement?
Yes. Under UK law and ACOP L8, a Legionella risk assessment is required wherever water is stored, used, or recirculated in ways that could create aerosol droplets.
How often do I need to review the assessment?
At least every 2 years — or sooner if changes occur to the water system, building use, or if there’s reason to believe it is no longer valid.
Who enforces Legionella law?
Local authorities and the Health and Safety Executive (HSE) both have enforcement powers depending on the setting.
Need to book a professional assessment? See our commercial Legionella testing service in Doncaster.
Or explore how to create a compliant written scheme of control.
Return to our homepage for full service details and pricing.
Need to book a professional assessment? See our commercial Legionella testing service in Doncaster.
Or explore how to create a compliant written scheme of control.
Return to our homepage for full service details and pricing.