Are there Legionella risks in my workplace?

Any water system, with the right environmental conditions, could be a source for legionella bacteria growth. There is a reasonably foreseeable legionella risk if your water system:

• has a water temperature between 20–45 °C
• creates and/or spreads breathable droplets, e.g. aerosol created by a cooling tower, or water outlets
• stores and/or re-circulates water
• likely to contain a source of nutrients for the organism to grow, e.g. rust, sludge, scale, organic matter and biofilms

The most common sources of legionella are in man-made water systems including:

• cooling tower and evaporative condensers
• hot and cold water systems
• spa pools

There are also a number of other potential risk systems that may pose a risk to exposure to legionella, e.g. humidifiers, air washers, emergency showers, indoor ornamental fountains etc.

If you are an employer, or someone in control of premises (e.g. landlord), you have a duty to understand and manage legionella risks. Further information is available in 'What you must do'. All systems require a risk assessment but not all systems will require elaborate control measures. A simple risk assessment may show that the risks are low and being properly managed to comply with the law.  If such cases, your assessment may be complete and you may not need to take any further action, but it is important to review your assessment regularly in case anything changes in your system.