What is ACOP L8

As a facilities manager, you have a legal and professional duty to keep building occupants safe. One of the most important areas of compliance is controlling the risk of Legionella in water systems. This is where ACOP L8 comes in. It is the Health and Safety Executive’s (HSE) Approved Code of Practice for managing Legionella risk, and it should form the backbone of your water safety strategy.

This guide explains what ACOP L8 is, why it matters, and what you need to do to stay compliant.

What is ACOP L8?

ACOP stands for Approved Code of Practice. L8 is the HSE’s document titled “Legionnaires’ disease: The control of legionella bacteria in water systems”. The current edition was published in 2013 and remains the definitive guidance for those responsible for managing water systems.

The code applies to:

• Employers, landlords, and those in control of premises

• Duty holders and “responsible persons”

• Anyone managing water systems in commercial, industrial, or residential environments

ACOP L8 sets out how to:

• Identify and assess Legionella risks

• Prepare and implement a written control scheme

• Monitor and record results

• Appoint competent individuals to manage compliance

Although ACOP L8 is not legislation, it has “special legal status”. If you are prosecuted under health and safety law and cannot demonstrate compliance with ACOP L8, you will need to prove you achieved at least the same level of safety by other means.

Why ACOP L8 Matters for Facilities Managers

For facilities managers, ACOP L8 is both a practical tool and a legal safeguard. Its purpose is to help you protect the health of staff, residents, and visitors while ensuring your organisation meets its duties under the law.

Key reasons why compliance is vital:

• Legal protection – Following ACOP L8 shows due diligence and helps defend against liability.

• Health and safety – Legionnaires’ disease can be severe and sometimes fatal. Preventing outbreaks is a critical responsibility.

• Reputation and business continuity – A failure to control Legionella can cause costly disruptions, fines, and reputational harm.

In short, ACOP L8 is your framework for maintaining safe, compliant water systems.

The Core Requirements of ACOP L8

Risk Assessment and Hazard Identification

The first step is a Legionella risk assessment carried out by a competent person. This should identify all potential sources of risk, such as:

• Hot and cold water systems

• Cooling towers and evaporative condensers

• Showers, taps, and other outlets that create aerosols

• Storage tanks and areas of stagnation

Conditions that encourage bacterial growth include water temperatures between 20°C and 45°C, the presence of scale or sediment, and infrequent use of outlets.

Appointing the Responsible Person

ACOP L8 requires you to appoint a responsible person. This individual should have sufficient knowledge and authority to manage compliance, oversee the control scheme, and ensure accurate record keeping. Ongoing training is essential to maintain competency.

Implementing a Control Scheme

A written control scheme is the practical roadmap for reducing risk. It should include:

• Maintaining hot water at 60°C or higher and cold water below 20°C

• Flushing little-used outlets

• Regular cleaning and disinfection of tanks and systems

• Removing dead legs and redundant pipework

• Inspecting, servicing, and maintaining system components

The scheme should be reviewed periodically and updated whenever systems change or new risks are identified.

Monitoring, Records, and Continuous Review

ACOP L8 places strong emphasis on monitoring and record keeping. You must:

• Keep detailed records of risk assessments, monitoring results, and maintenance activities

• Ensure test results and corrective actions are clearly logged

• Review the effectiveness of your control measures regularly

Accurate documentation is your evidence of compliance and will be critical if your organisation is ever audited or investigated.

Related Legislation and Guidance

ACOP L8 sits within a wider framework of UK health and safety law, including:

• HSG274 – technical guidance covering different system types (hot and cold water, cooling systems, etc.)

• Health and Safety at Work etc. Act 1974 – the overarching law on workplace safety

• Control of Substances Hazardous to Health Regulations 2002 (COSHH) – which classifies Legionella as a hazardous substance

• Management of Health and Safety at Work Regulations 1999 – requiring risk assessments and management processes

Understanding these connections will help you build a robust compliance programme.

What Happens If You Are Not Compliant

Failure to follow ACOP L8 can have serious consequences:

• Legal action, fines, and enforcement notices

• Business disruption and costly remedial works

• Reputational damage that can affect long-term operations

• Most importantly, the potential for illness or death among building users

Compliance is not just a regulatory burden—it is a moral responsibility to safeguard those who use your facilities.

Summary

ACOP L8 provides a clear, structured approach to managing Legionella risk in water systems. By:

• Conducting a thorough risk assessment

• Appointing a competent responsible person

• Implementing and reviewing a control scheme

• Keeping accurate monitoring and maintenance records

…you can ensure compliance, protect health, and reduce legal risk.

To deepen your understanding, you may find it helpful to explore our resources on Legionella Remedial Works, Cold Water Tanks, and Hot Water Systems. These will give you practical insights into how ACOP L8 requirements apply in real-world systems.