What is this document?
L8 is the Approved Code of Practice (ACOP) and guidance published by the Health and Safety Executive (HSE). Now in its fourth edition (2013), it is the authoritative document on controlling legionella bacteria in water systems.
Unlike advisory guidance, an ACOP has special legal status. If you are prosecuted for a health and safety breach related to legionella, and it is proven you did not follow the relevant provisions of L8, you will need to show you complied with the law in some other way — or a court will find you at fault.
Who needs to read this?
L8 applies to anyone with duties under health and safety law who controls premises with water systems. This includes:
- Employers responsible for employees and others who may be affected by their work
- Landlords with control over water systems in rental properties
- Property managers with day-to-day responsibility for building water services
- Care home operators with particularly vulnerable occupants
- Healthcare providers including hospitals, clinics, and dental practices
- Hotel and leisure operators with showers, cooling towers, or spa facilities
- Building owners and occupiers through lease or maintenance agreements
- Anyone designated as the 'responsible person' for water safety
If you have any responsibility for water systems, L8 is essential reading.
Key points covered
The fourth edition of L8 covers:
Legal duties and responsibilities
- Who qualifies as a dutyholder
- The requirement to identify and assess sources of risk
- Appointing a 'responsible person' to take day-to-day control
- What competence means for those carrying out risk assessments and control measures
Risk assessment
- How to conduct a suitable and sufficient legionella risk assessment
- What the assessment must cover
- When to review the assessment (at least every 2 years, or when circumstances change)
Written scheme of control
- Preparing a scheme that prevents or controls the risk
- What the scheme must include
- Implementing, managing, and monitoring the scheme
Competence and training
- What competence means for those involved in legionella control
- Training requirements for responsible persons and operatives
Record keeping
- What records to maintain
- How long to keep records (at least 5 years recommended)
Review and monitoring
- Ongoing monitoring of control measures
- When and how to review arrangements
What changed in the fourth edition?
The 2013 revision made significant changes:
- Technical guidance removed — Detailed technical guidance is now in HSG274 (Parts 1, 2, and 3), not L8 itself
- Four areas elevated to ACOP status — Risk assessment procedures, the 'responsible person' role, control schemes, and review processes now have full ACOP status
- Water supply duties clarified — Responsibilities across the water supply chain are now clearer
How this applies to you
If you are a dutyholder, L8 requires you to:
- Identify and assess risk — Know where legionella could grow and be dispersed in your premises
- Appoint a responsible person — Someone competent to take day-to-day responsibility
- Prepare a written scheme — Document how you will prevent or control legionella risk
- Implement the scheme — Actually carry out the control measures
- Monitor and record — Keep records of checks, maintenance, and any issues
- Review regularly — At least every 2 years or when circumstances change
For detailed technical guidance on specific systems, you should also consult:
- HSG274 Part 1 — Evaporative cooling systems (cooling towers)
- HSG274 Part 2 — Hot and cold water systems
- HSG274 Part 3 — Other risk systems (spa pools, water features, etc.)
The legal significance of L8
L8 is not just guidance — it is an Approved Code of Practice with special legal status:
- Following L8 is not strictly mandatory
- However, if you are prosecuted and have not followed L8, you must prove you achieved an equivalent level of safety another way
- In practice, following L8 gives you a strong legal defence
- Courts and regulators treat L8 as the benchmark for legionella compliance
Related Safety Clarity content
- Legionella Control and Water Safety — Our complete guide to legionella compliance
- INDG458: Brief Guide for Dutyholders — The introductory leaflet for those new to legionella
- Do I need a legionella assessment? — Check if legionella controls apply to you
- Legionella risk assessment guide — Understanding what is involved
- Landlord's guide to legionella — Specific guidance for residential landlords
Read the official document: L8 on HSE website
Disclaimer: This summary is for general information only and does not constitute legal advice. Always refer to the official HSE publication for authoritative guidance. For complex water systems or high-risk premises, seek professional advice from a competent legionella specialist.