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Legionella Risks in the Workplace.


We are able to carry out a risk assessment to help decide whether you are at risk and if so put prevention techniques into place.


The following paragraphs list some of the possible sources of the disease, but if you are at all in doubt, let us carry out an assessment to ensure that your Health and Safety procedures are in place to prevent any occurrence.


A cooling tower or evaporative condenser


Monitoring water quality, inspection, cleaning and disinfection.


Dry/wet cooling systems (sometimes referred to as hybrid or adiabatic coolers)


In recent years there has been increasing use of dry/wet cooling systems, these are designed to operate both in dry air cooled mode and wet evaporative cooling mode. There are different types of dry/wet cooling systems, sometimes referred to as “hybrid” or “adiabatic” coolers, and these can have a wide range of risk profiles.


We can help dutyholders, which includes employers, those in control of premises and those with health and safety responsibilities for others, to comply with their legal duties and gives practical guidance on how to assess and control the risks due to legionella bacteria in dry/wet cooling systems.


Hot and cold water systems


There are various systems available to supply hot and cold water services that range in size, scale and complexity. All can present foreseeable risk of exposure to legionella. Temperature control is the traditional strategy for reducing the risk of legionella in hot and cold water systems. Cold water systems should be maintained, where possible, at a temperature below 20°C. Hot water should be stored at least at 60°C and distributed so that it reaches a temperature of 50°C (55°C in healthcare premises) within one minute at the outlets.




Spa-pool systems are increasingly popular and can be found in a variety of sizes and settings. They are known by various names including hot spas, hot tubs, whirlpool spas and portable spas. Such systems pose a reasonably foreseeable risk as they are a recognised source of diseases caused by infectious agents including the organism that causes legionnaires’ disease, primarily Legionella pneumophila. There have been a number of outbreaks linked to spa-pool systems in leisure centres, hotels, holiday homes, on cruise ships and on display.


Other potential risk systems


in addition to evaporative cooling systems, hot and cold water systems and spa pools, there are a number of other risk systems, e.g. humidifiers, air washers, emergency showers, eye wash sprays, indoor ornamental fountains, aqueous tunnel washers etc that could potentially be a source for legionella bacteria growth.


If you have any systems on site that have the potential for causing an outbreak of legionella, call us today for a risk assessment followed by any preventive procedures necessary.