Legionella Risk Assessment

What Is Legionnaires’ Disease?

It is a potentially fatal pneumonia caused by legionella bacteria. You can become infected by breathing in small droplets of water, which has become contaminated by the bacteria.

Who Does It Affect?

All are potentially susceptible to infection but higher risk categories include the over 45’s, smokers and heavy drinkers and those suffering from chronic respiratory or kidney disease and those persons who have an impaired immune system. It cannot be passed from person to person.

Where Are The Legionella  Bacteria Found?

Commonly found in natural water courses such as rivers and ponds. Legionella bacteria are widespread in our environment and can contaminate other water systems such as cooling towers and hot and cold water services.

The bacteria can survive low temperatures and thrive in temperatures between 20-45°C if conditions are suitable, e.g. if a supply of nutrients is present such as rust, sludge, scale, algae and other bacteria. High temperatures kill the bacteria.

What Are My Duties Under The Law?

The responsibility for risk assessment rests with the employer or person who controls the premises.

Simply Think UK have trained assessors nationwide who can establish the following:

• Are conditions present that will encourage bacteria to multiply? E.g. water temperature between 20-45°C
• Are water droplets being produced and if so are they being dispersed?  E.g. consider showers and aerosols from cooling towers.
• Will anyone who may be susceptible come into contact with contaminated water droplets?

Which Systems Present The Higher Risk?

Cooling towers, evaporative condensers, hot and cold water systems have all been associated with outbreaks. Alternative potential sources include humidifiers and spa baths.

What Records Do I Need To Keep?

If more than five people are employed any significant findings following a risk assessment must be recorded. This means recording significant findings of the assessment and details of any monitoring or checking out. Written records have to be kept for a minimum of 5 years together with who is responsible for managing the scheme.

Do I Have Any Other Duties?

If you have cooling towers or evaporate condensers on site you must, under the Notification of Cooling Towers and Evaporate Condensers Regulations, notify the local authority in writing with details of location. They must also be informed when/if such devises are no longer in use.

If you have a case of legionellosis in an employee who has worked on cooling towers or hot water systems that are likely to be contaminated with legionella, you have to report this under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations.