Wednesday 20th May, 2026
Illustration by TEAM Safety Services Ltd.
As temperatures begin to rise across the UK, many organisations will focus on keeping buildings cool and comfortable. However, summer conditions can also create the perfect environment for Legionella bacteria to grow, particularly within water systems and air conditioning units.
Understanding this seasonal risk is essential for anyone responsible for managing buildings, facilities, or water systems.
Why Does Legionella Risk Increase in Summer?
Legionella bacteria thrives in warm, stagnant water, particularly between 20°C and 45°C.
During the summer months:
Cooling towers and water-based air conditioning systems are particularly important to monitor, as they can produce fine aerosols that may spread bacteria over wide areas if not properly maintained.
Fine aerosols are tiny water droplets that are small enough to remain suspended in the air and be inhaled into the lungs. As Legionella becomes a health risk when inhaled, this is where the danger lies.
FOR 30% OFF LEGIONELLA AWARENESS eLEARNING USE DISCOUNT CODE: BLOG30
Air Conditioning Systems: A Key Risk Area
While modern air conditioning systems are often air-cooled, some systems still rely on water, such as cooling towers and evaporative condensers.
If these systems are poorly maintained, they can:
Historically, many large Legionella outbreaks have been linked to cooling systems, highlighting the importance of regular inspection and maintenance.
Simple Steps to Reduce the Risk
Managing Legionella risk does not need to be complicated, but it does require consistency and awareness. Key control measures include:
1. Control Water Temperatures
Ensure that:
2. Prevent Stagnation
Effective flushing involves opening outlets fully to remove stagnant water, running hot water until it reaches at least 50°C within one minute of running, and cold water must drop below 20°C within approximately two minutes. The goal is to run the outlet until the temperature stabilises and matches the incoming supply temperature.
Infrequently used outlets should typically be flushed weekly, while higher-risk environments may require more frequent flushing. Care should also be taken to minimise splashing and aerosol generation.
3. Maintain and Clean Systems
4. Monitor and Record
5. Review Your Risk Assessment
Legal Responsibilities
Under UK legislation, including the Health and Safety at Work etc. Act 1974, The Management of Health and Safety at Work Regs 1999, Reporting Injuries, Diseases and Dangerous Occurences Regulations (RIDDOR) 2013, and The Control of Substances Hazardous to Health Regulations (COSHH) 2002, duty holders are legally required to identify, assess, and control Legionella risks.
Failure to do so can lead to serious consequences, including illness, prosecution, and significant fines.
Build Knowledge, Reduce Risk with our Legionella Awareness eLearning
To support organisations in managing these risks, TEAM Safety Services has launched a new Legionella Awareness eLearning course.
This course is designed to give learners a clear understanding of:
It is ideal for duty holders, facilities teams, housing providers, and anyone responsible for water safety.
FOR 30% OFF LEGIONELLA AWARENESS eLEARNING USE DISCOUNT CODE: BLOG30
Legionella is a preventable risk, but only when it is properly understood and managed. As summer temperatures rise and cooling systems come into increased use, now is the time to review your controls and ensure your systems remain safe.
If you need support with training or risk management, TEAM Safety Services is here to help.
Share this post:
Fire Door Safety Week, taking place this year from 21st–25th September, is an important reminder of the role fire doors play in protecting people, property and escape routes. But fire door safety isn’t something that should only receive attention during an awareness week, or when an inspection is due. In this month’s blog, we share what you should be doing throughout the year to manage your fire doors.
Most organisations provide health and safety training. Employees complete inductions, courses are attended, certificates are issued, records are stored; but there is a much more important question to ask: Is the training actually working? In this month’s blog, we share what you should be considering and checking to ensure your workforce is competent and confident.
As we reach the halfway point of 2026, it’s an opportunity to pause and reflect on what has already been an incredibly busy and rewarding year for TEAM Safety Services. In this month’s blog, we share some of our highlights from 2026 so far.
Sign up to recieve news, training and advice straight to your inbox
Got a question?
Call us on: 0800 0283668
Email us: info@teamsafetyservices.com
Give your business a Safety Net
For a simple all-in-one health and safety package take a look at our "Safety Net" packages from TEAM Safety Service today.
© 2023 Team Safety Services Ltd. All Rights Reserved. Company No: 07069072. VAT No: GB994972249