Legionella Risk Assessments

We can provide Legionella risk assessments and management strategies.

As an employer or a person in control of premises, you must appoint person or persons responsible for helping you manage your health and safety duties, e.g. take responsibility for managing risks. A competent person is someone with the necessary skills, knowledge and experience to manage health and safety, including the control measures.

We can provide Legionella risk assessments and management strategies.

What is Legionnaires’ disease?

Legionnaires’ disease is a form of pneumonia caused by the bacterium Legionella pnuemophila. The disease was first identified after a convention of the American Legion in Philadelphia in 1976, resulting in 12 deaths. Legionnaires’ disease is one of a group of diseases with those most at risk including smokers, alcoholics, and people suffering from cancer, diabetes, and chronic respiratory or kidney disease. Healthy people can also be infected. Legionella bacteria are widespread in natural sources of water including rivers, streams, ponds and may even be found in soil. They are also found in many recirculating and hot and cold water systems. Outbreaks of Legionella disease have occurred in or near large building complexes such as hotels, hospitals, offices and factories. Cooling towers such as those that form part of an air conditioning system can represent a particular hazard because they readily generate fine water droplets and there is an air current to carry them away.

Do I need a Legionella risk assessment?

The purpose of carrying out a risk assessment is to identify and assess any risks in your water system. The responsible person should understand your water systems and any associated equipment, in order to conclude whether the system is likely to create a risk from exposure to legionella, and should be able to identify whether:

water is stored or re-circulated as part of your system
the water temperature in some or all parts of the system is between 20–45 °C
there are sources of nutrients such as rust, sludge, scale and organic matters
conditions are present to encourage bacteria to multiply
it is possible for water droplets to be produced and, if so, whether they could be dispersed over a wide area, eg showers and aerosols from cooling towers
it is likely that any of your employees, residents, visitors etc are more susceptible to infection due to age, illness, a weakened immune system etc and whether they could be exposed to any contaminated water droplets

How often should you do a Legionella risk assessment?

You need to review the assessment regularly and specifically when there is reason to believe that the original risk assessment may no longer be valid. You should also review management and communication procedures as appropriate.

It should be updated regularly and at least every 2 years.

(Contains public sector information published by the Health and Safety Executive and licensed under the Open Government Licence).