FAQs

Legionella bacteria are commonly found in natural and artificial water systems. While not everyone exposed to the bacteria will develop illness, it is important to take preventive measures. The infectious dose is clearly linked to susceptibility, although it is considered to attack between 2-5% of those exposed.

Symptoms of Legionnaires’ disease can include high fever, cough, shortness of breath, muscle aches, and headaches. In severe cases, it can lead to pneumonia and other complications.

Preventing Legionella requires regular maintenance and cleaning of water systems, as well as implementing proper disinfection and monitoring protocols.

Legionella bacteria can spread through the inhalation of contaminated water droplets, such as those from showers, taps, or cooling towers.

Legionella is a type of bacteria that can cause a severe form of pneumonia called Legionnaires’ disease. It is commonly found in water systems and can be harmful if inhaled. It was named after an outbreak of severe pneumonia that affected a meeting of the American Legion in 1976.

A suitable risk assessment is required to cover all water systems in any commercial premise. This includes rented housing stock particularly where communal services are present.

Guidance details that the risk assessment should be up-dated regularly (at least every two years) or when there are significant changes that may render the assessment invalid (e.g. change in water systems / change in occupants / legionella bacteria found / legionella outbreak). In order to identify any changes it is recommended that a formal desk based review is under taken regularly with findings being recorded.

The control scheme which will be completed and detailed in the legionella risk assessment report will identify the tasks that are required to control the risks. The level of monitoring required will depend on the type of water systems and services and users within your site. A basic water system for example in a 5-storey office block may require monthly temperature checks, six monthly & annual inspections (other tasks may include quarterly shower head cleaning or weekly flushing of infrequently used outlets).

Specific guidance regarding the control of legionella bacteria is supplied in Legionnaires’ disease – The control of legionella bacteria in water systems. Approved Code of Practice and guidance L8.

Downloadable from the HSE website – www.hse.gov.uk/pubns/priced/l8.pdf

A leaflet briefly defining your legionella obligations is downloadable from the HSE website and we strongly recommend you take the time to read this leaflet as a starting point Legionnaires’ disease a guide for employers – Click Here

The Health and Safety at Work act 1974 and the Control of Substances Hazardous to Health Regulations place legal duties on employers and those responsible for the control of premises to control the risk from exposure to bacteria.

The Approved code of Practice and guidance more commonly known as L8 gives advice on these legal duties and sets out strategies for controlling the risk.

The five key areas that are required to comply with legal duties are;

• Identify and assess source of risk
• Prepare a scheme for preventing or controlling the risk
• Implement, manage, and monitor precautions
• Keep records
• Appoint a person to be managerially responsible

There are several measures that can be adopted to create water systems in the built environment that are hostile to the growth of legionella. Most traditionally, temperature is used to control legionella. Wherever possible, temperature should be the first line of defence used to control the bacterial growth.

System Required Temperature:

Hot water storage – 60 Deg. C
Hot Water Distribution Greater than – 50 Deg. C
Cold water Storage Less than – 20 Deg. C
Cold Water Distribution Less than – 20 Deg. C

It is also particularly important to ensure that all areas of the distribution system are in regular use to safe guard against stagnation.