Legionellosis is a broad term for diseases caused by the legionella bacteria including legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever. Legionnaires’ disease is a serious form of pneumonia and everyone is susceptible to infection. The risk increases with age, but some people are at higher risk, such as people over 45, smokers and heavy drinkers, people suffering from chronic respiratory or kidney disease, diabetes, lung and heart disease or anyone with an impaired immune system.
The bacterium Legionella pneumophila and related bacteria are common in natural water sources such as rivers, lakes and reservoirs, but usually in low numbers. They may also be found in purpose-built water systems, such as cooling towers, evaporative condensers, hot and cold water systems and spa pools. If conditions are favourable, the bacteria may multiply, increasing the risks of legionnaires’ disease, and it is therefore important to control the risks by introducing appropriate measures.
Legionella bacteria are widespread in natural water systems. However, the conditions are rarely conducive for people to catch the disease from these sources. Outbreaks of the illness occur from exposure to legionella growing in purpose-built systems where water is maintained at a temperature high enough to encourage growth.
Legionnaires’ disease is normally contracted by inhaling small droplets of water (aerosols), suspended in the air, containing the bacteria. Certain conditions increase the risk from legionella if:
It is important to control the risks by introducing measures which do not allow proliferation of the organisms in the water systems and reduce, so far as is reasonably practicable, exposure to water droplets and aerosol. This will reduce the possibility of creating conditions in which the risk from exposure to legionella bacteria is increased.
This ACOP applies to the control of legionella bacteria, in any undertaking or system involving a work activity managed by you or your business. It applies to premises controlled in connection with a trade, business or other undertaking where water is used or stored, and where there is a means of creating and transmitting aerosols which may be inhaled, causing a reasonably foreseeable risk of exposure to legionella bacteria.
An Approved Code of Practice describes and outlines the preferred or recommended methods that can be used, or standards to be met, to comply with the Regulations and the duties imposed by the Health and Safety at Work etc Act 1974. The guidance also provides advice on achieving business compliance, or it may give general information, including explaining the requirements of the law, more specific technical information or references to further sources of information. All ACoPs are approved by the Health and Safety Executive (HSE) Board.
