ACOP L8


Legionella Control and Prevention: What is ACOP L8?

Legionella is a pathogenic bacteria whose trace amounts can be found in natural water resources such as lakes or rivers. However, when the environmental conditions are right, legionella can also survive in purpose-built water systems and put people's health at risk. Legionella spreads in water droplets that can be inhaled when suspended in the air and cause serious respiratory diseases such as Pontiac fever or a type of pneumonia called Legionnaires’ disease. 

Since legionella poses a threat to a person's health, all duty holders must be aware of methods to prevent and control risks associated with its exposure and act according to the Approved Code of Practice (ACOP) L8, which you will find more about in this article.

What Is ACOP L8?

Every duty holder (an employer, premises owner, a landlord, etc.) is legally required to comply with health and safety requirements when there is a risk of exposure to legionella. Approved Code of Practice (ACOP) L8 offers advice on meeting the requirements outlined in the Health and Safety at Work etc. Act 1974, the Control of Substances Hazardous to Health Regulations 2002 and the Management of Health and Safety at Work Regulations 1999.

Is ACOP L8 Compulsory?

ACOP L8 is not compulsory. However, it was approved by the Health and Safety Executive (HSE) and thus, following its guidelines ensures that you are complying with the law. Of course, you can rely on other codes of action, but ACOP L8 contains all the practical guidance you will need.

Why Is ACOP L8 Important? 

Complying with ACOP L8 is vital because it ensures that no one's health is put at risk and, because it holds a special legal status, compliance can also protect you from prosecution. If you are accused of having breached health and safety laws and fail to demonstrate that you had acted according to the ACOP L8 guidance, you will have to prove that you followed the law in an alternative way.

What Does ACOP L8 Cover?

ACOP L8 is designed for duty holders who have legal obligations to prevent legionella exposure in the workplace. As a duty holder, you are required to identify and assess sources of risk, prepare a plan to prevent or control the risks, implement, manage and monitor the precautions and keep these precautions on the record. 

ACOP L8 covers:

  • Completing risk assessments.
  • The role of the appointed person.
  • The control scheme for legionella risks.
  • Review of control measures.
  • The duties of individuals involved in the supply of water systems.

Keep in mind that the technical guidance on evaporative cooling systems, hot and cold water systems and other risk systems has been removed from the newest edition of ACOP L8 and can now be found in HSG274. If you require guidance on spa pools, it can be found in HSG282. 

For more in-depth information, visit our website to access an awareness course covering L8 and HSG274.  

Is an ACOP L8 Legionella Risk Assessment Necessary, and What Does It Include?

A legionella risk assessment is necessary regardless of the type of water system your workplace uses. An assessment should be carried out by a competent person responsible for ensuring the measures comply with the law. As a duty holder, you are responsible for appointing that individual. The appointed person could be yourself, an employee or an outside person as long as they possess the necessary skills and expertise.

For a more in-depth understanding of risk assessments, visit our Online Risk Assessment Training Course. 

An ACOP L8 legionella risk assessment must identify the risks in order to help you evaluate whether the exposure to legionella can be avoided, and identify the measures that can be implemented to reduce that risk if prevention is not possible. 

The risk assessment must also offer guidance on the controls that can be put in place to prevent legionella growth. This guidance might include:

  • Avoiding maintaining a water temperature of between 20-45°C in any part of your water system because it encourages legionella to grow.
  • Ensuring that water systems are thoroughly cleaned to prevent a biofilm from forming, which can allowing legionella to grow. For the same reason, it is important to avoid water stagnation. You should pay attention to the water flow, aerate it if necessary and control the release of water spray. It is also important to regularly flush out outlets and remove dead legs in the pipework.
  • Using materials in a water system that comply with UK legal requirements to prevent harbour of bacteria. The Water Fittings and Material Directory lists appropriate fittings, appliances, and materials. 
  • Being mindful of the condition of the water systems. For instance, rust, sludge, scale and organic matters can increase the risk of bacteria growth. 

If the risk of legionella growth cannot be prevented, appropriate safety measures must be implemented to help manage it. In order to do that, you have to identify: 

  • What type of system you have.
  • The person in charge of carrying out the assessment and managing its application.
  • The correct way to operate your system.
  • The precautions and control methods that will be used.
  • What checks will be introduced to ensure the risks are being controlled.
  • How often these checks should be carried out.

All individuals at risk should be made aware of this risk assessment, and the safety measures contained within it. In addition, if the number of employees exceeds 5, you are required to record your findings, including:

  • The written control scheme and details on its implementation.
  • The groups that are particularly at risk of contracting legionella.
  • The person responsible for conducting risk assessment and taking action.
  • The results of inspections or checks with dates.
  • The main findings of the risk assessment.

The risk assessment should be reviewed regularly to ensure that the implemented precautions are adequate and report any changes. These might refer to hiring new employees who require training, changes to the system or the personnel, and a case of any legionella-related disease.


If you are looking to complete a Legionella course, consider taking our online Legionella Awareness Training Course Online or Legionella Awareness for Duty Holders Training courses which, unlike classroom courses, can be completed in your own time and at your own pace.