Legionella

Legionnaires disease

Legionellosis is the term for infections caused by Legionella Pnuemophila with the best known illness being Legionnaires Disease. This is a type of pneumonia that principally affects people that are susceptible due to age, illness, immuno-supression, smoking and can be fatal.

The bacteria can also cause less serious illnesses which are not fatal or permanently debilitating, but which can affect all people.

Symptoms

Typical symptoms include:

  • fever
  • headache
  • muscle pains
  • difficulty in breathing
  • cough
  • diarrhoea
  • vomiting 
  • mental confusion

The risk

Legionella can enter water systems and have no effect on people working or living in a building. A number of conditions are required to create the risk of Legionnaires Disease, there are:

  • Conditions suitable for multiplication of the organisms to high numbers, such as temperatures of 20oC to 45oC
  • A source of nutrients from sludge, scale, rust, algae and other organic matter
  • A means of creating and spreading breathable droplets, such as the aerosol generated by a cooling tower or shower
  • Susceptible individuals

Premises at risk

These include

  • premises with water systems incorporating a cooling tower or evaporative condenser
  • buildings with large and complex hot and cold water systems
  • any building where the spa pools occupants are particularly susceptible such as hospitals or care homes
  • leisure centres

This site provides information on Legionella and how to control risks from exposure to Legionella from manmade water systems.

It will help employers and those with responsibility for the control of premises understand what their duties are and how to comply with health and safety law 

Spa pools

Spa pools also known as hot tubs, whirlpool spa, whirlpools, Jacuzzis can offer a pleasant relaxing environment.

However the water is not replaced after each use but disinfected and re-circulated. If they are not managed properly spa pools can be the cause of infections. The most severe is the potentially fatal Legionnaires' disease which has even been caused when the spa pools were simply on display for sales purposes.

As a recognised source of Legionnaires' disease they are subject to health and safety laws requiring managers, designers, manufacturers and installers to ensure spa pools remain safe.

Whirlpool baths are similar to spa pools but are normally only used by one or two people at a time, are often found in bathrooms and are drained after each use but they are still a potential source of infections if not looked after properly.

Legal requirements

The Control of Substances Hazardous to Health Regulations 2002 (COSHH) relates to the risks from hazardous micro-organisms, including Legionella and chemicals such as biocides and chlorine. Under these Regulations risk assessments and the adoption of appropriate precautions are required to be made.

The Approved of Code of Practice and Guidance - The control of Legionella Bacteria in Water Systems sets out further statutory requirements for dealing with this risk.

Further information

The Health and Safety Executive (HSE) website provides detailed information on Legionella and how to control risks from exposure to Legionella from manmade water systems. It will help employers and those with responsibility for the control of premises understand what their duties are and how to comply with health and safety law. 

Further guidance on how to manage and control the risk from legionella in spa pools can be found on the Public Health England website.