While the lung infection known as Legionnaire’s disease – as can be contracted by breathing in water droplets containing the legionella bacteria – is uncommon, its consequences for sufferers’ health can be extremely serious.
This is why it is vital for duty holders – such as employers – to take seriously the legal responsibility they have to help guard against legionella and its risks.

What is the law regarding legionella?
All businesses in the UK have a legal duty to ensure the safety of the buildings, facilities and equipment under their control from the threat of legionella growth.
A risk assessment is recognised as an essential first stage in managing the risks that legionella on work premises can pose to human health.
Is a legionella risk assessment mandatory?
The Health and Safety Executive (HSE)’s Approved Code of Practice (ACOP) L8 document sets out the recommended measures for controlling the risks posed by legionella bacteria in water systems.
The document makes clear that in accordance with relevant regulations on Health and Safety at Work (HSAW) and the Control of Substances Hazardous to Health (COSHH), a suitable and sufficient assessment must be carried out on the risks from any work that could expose employees to a substance hazardous to their health.
This includes identifying and assessing the risk that work activities and water systems on the premises may pose to workers coming into contact with the legionella bacteria.
The duty holder is responsible for making sure this assessment is carried out, with the duty holder being the employer, a self-employed person, or the person in control of the premises or systems related to work.
How often do I need a legionella risk assessment?
In order to satisfy the requirements laid out by ACOP L8, duty holders should ensure a legionella assessment is carried out every two years.
However, if there have been changes to the water systems at your premises or how they are used, it may be necessary to have a new risk assessment undertaken sooner than this.
A new legionella risk assessment may also be needed if you find that existing legionella control measures on your site have ceased to work, new information about how to control the risks arising from legionella has become protocol, or the way the wider building is used has changed.
The five steps of a legionella risk assessment
- Identify the hazards. You will first need to examine your premises and identify where the potential may exist for legionella to grow – and thereby pose a risk to the health of those using the facility. You should account for the individual nature of the site for which you are undertaking the assessment, and the possible risks posed by the system as a whole, instead of simply looking at specific parts of the building in isolation.
- Consider anyone who may be at risk and where the risk is. You should think about all of the people who may be present on your site from time to time, and the areas where risks could arise as a consequence of their activities there. Any changes to key personnel at your site will also necessitate looking again at your risk assessment. If you are an employer, you are required to consult employees or their representatives on the risks of legionella exposure that you identify at your site, and the measures and actions taken to control those risks. Employees should also be afforded the opportunity to comment on the assessment and control measures, and as an employer, you are expected to take account of their views.
- Implement strict measures for control. Assess the controls that you should already have in place at your building, and make sure there is a procedure for adequate controls to be introduced and routinely followed. The effectiveness of control measures will need to be monitored over time, so you’ll need to make decisions as to when and how monitoring should take place.
- Keep written records. Whatever risks you identify, and whatever measures you implement to limit those risks, a written record ought to be kept of them. The ACOP L8 states that the significant findings of an assessment must be recorded where there are five or more employees. However, even if this isn’t the case, recording details of the assessment will enable you to show what you have discovered, and what steps are being taken.
- Review the risk assessment. As touched on above, changes can occur over time, whether to your water systems or other aspects of your premises, including how they are used. It’s therefore important to periodically review the risk assessment to allow any new risks on your site to be identified, and effective control measures to be implemented. Any case of legionella’s disease linked to your premises should also prompt you to look again at your risk assessment.
Making use of software for better legionella risk management
The right software system can greatly help property owners and landlords to keep on top of their duty of care responsibilities, when it comes to the control of legionella risks.
Our Legionella Risk Management Software platform here at Assets & Compliance Managed Services UK is just one part of our broader acclaimed compliance management platform, Vision. It is easy to configure in line with your needs and circumstances, including whether you are undertaking risk assessments for a single property or multiple buildings in your portfolio.
During the recent covid times in which many commercial buildings have been left vacant for extended periods, water may have become stagnant, and the associated risk of legionella may have increased. This underlines the importance of duty holders ensuring a complete legionella risk assessment has been undertaken before the building is again made accessible to workers and members of the public.

The Assets & Compliance Managed Services UK Legionella Risk Management Software platform incorporates such features as hot water and cold water systems analysis tracking, an assessments management tab for logging all of the assets making up your property or property portfolio, and a reports function for generating electronic or hard-copy risk assessment reports.
The Vision legionella software, combined with the use of Vision-tags, also allows the user to scan a tag and upload information such as water temperatures, making it easy for service personnel to maintain and manage. To learn more about our Vision software and its role in helping you to better manage the risks of legionella at your residential or business property, please call Assets & Compliance Managed Services UK today.