Legionella/ Legionnaires Disease

Legionellosis is a collective term for diseases caused by legionella bacteria including the most serious Legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever.

Legionnaires’ disease is a potentially fatal form of pneumonia and everyone is susceptible to infection.

National Services Scotland

This information will help employers and those with responsibility for the control of premises, including landlords, understand what their duties are and how to comply with health and safety law.  It applies to premises controlled in connection with a trade, business or other undertaking where water is stored or used, and where there is a means of creating and transmitting breathable water droplets (aerosols), thus causing a reasonably foreseeable risk of exposure to legionella bacteria.

If you require additional information you can contact the NSS Health & Safety Advisors through HR Connect Contact Us / Health and Safety.

NHS 24

NHS 24's Legionella Policy can be found here.

Public Health Scotland

Public Health Scotland content is being designed for this page, in the interim please refer to the National Services Scotland Tab for support.  
If you require additional information you can contact the NSS Health & Safety Advisors through HR Connect Contact Us / Health and Safety.

Scottish Ambulance Service

The Scottish Ambulance Service is committed to provide and maintain safe and healthy working conditions, equipment and systems of work for all staff and visitors, and to provide such resources, information, training and supervision as needed for this purpose.

The Scottish Ambulance Service will ensure that the water supply, storage and distribution services within its properties are installed and operated within the terms of the following legislation:

  • Health Technical and Memorandum 04-07 The Control of Legionella, Hygiene, "Safe" Hot Water, Cold Water and Drinking Water Systems
  • Health and Safety at Work Act 1974
  • The Management of Health and Safety at Work Regulations 1992
  • Water Supply (Water Quality) Regulations 1988
  • Public Health (Infectious Disease) Regulations 1988
  • British Standards 6700:1997 and BS1710: 1984
  • The Health and Safety Commission’s (2000) Approved Code of Practice L8
  • Water Supply (Water Fittings) Regulations 1999
  • Control of Substances Hazardous to Health (COSHH) Regulations 2002
  • ACOP L8
  • HSG 274 Parts 2 and 3
  • SHTM 04-01 Water Safety for Healthcare Premises
    • Legionella - Are there Legionella risks in my workplace?National Services Scotland, Public Health Scotland

      Any water system that has the right environmental conditions could potentially be a source for legionella bacteria growth. There is a reasonably foreseeable legionella risk in your water system if:

       - water is stored or re-circulated as part of your system;

       - the water temperature in all or some part of the system is between 20–45 °C;

       - there are sources of nutrients such as rust, sludge, scale and organic matters;

       - the conditions are likely to encourage bacteria to multiply;

       - it is possible for water droplets to be produced and, if so, if they can be dispersed over a wide area, eg showers and aerosols from cooling towers; and

       - 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.

      The most common places where legionella can be found include purpose-built water systems, cooling towers, evaporative condensers, hot and cold water systems and spa pools. There are also a number of other systems that may pose a risk to exposure to legionella, eg humidifiers, air washers, emergency showers, indoor ornamental fountains etc.

    • Do I need to keep a record of employees with Legionnaires?National Services Scotland, Public Health Scotland

      If you have five or more employees, you have to record any significant findings, including any groups of employees identified by it as being particularly at risk and the steps taken to prevent or control risks.

      If you have less than five employees, you do not need to write anything down, although it is useful to keep a written record of what you have done.

      Records should include details about:

       - the person or people responsible for conducting the risk assessment, managing, and implementing the written scheme;

       - any significant findings of the risk assessment;

       - the written control scheme and its implementation; and

       - the results of any inspection, test or check carried out, and the dates.

      This should include details about the state of operation of the system, ie in use/not in use.

      These records should be retained throughout the period for which they remain current and for at least two years after that period. Records kept in accordance with the last bullet point above should be retained for at least five years.

      If you require additional information, please review your Business Unit Risk profile and / or NSS Facilities Management

    • How do I prevent or control the risk of Legionella?National Services Scotland, Public Health Scotland

      You should consider whether you can prevent the risk of legionella in the first place by considering the type of water system you need, eg consider whether it is possible to replace a wet cooling tower with a dry air-cooled system. The key point is to design, maintain and operate your water services under conditions that prevent or adequately control the growth of legionella bacteria.

      You should, as appropriate:

       - ensure that the release of water spray is properly controlled;

       - avoid water temperatures and conditions that favour the growth of legionella and other micro-organisms;

       - ensure water cannot stagnate anywhere in the system by keeping pipe lengths as short as possible or by removing redundant pipework;

       - avoid materials that encourage the growth of legionella.

       - keep the system and the water in it clean; and

       - treat water to either kill legionella (and other microorganisms) or limit their ability to grow.

      If you identify a risk that you are unable to prevent, you must introduce appropriate controls. You should introduce a course of action that will help you to control any risks from legionella by identifying:

       - your system, eg developing a written schematic;

       - who is responsible for carrying out the assessment and managing its implementation;

       - the safe and correct operation of your system;

       - what control methods and other precautions you will be using; and

       - what checks will be carried out to ensure risks are being managed and how often.

      If you require additional information, please review your Business Unit Risk profile and / or NSS Facilities Management

    • How do I manage the risk of Legionella?National Services Scotland, Public Health Scotland

      As an employer or person in control of premises, you must appoint someone competent to help you comply with your health and safety duties, eg take responsibility for managing the risks. A competent person is someone with the necessary skills, knowledge and experience to manage health and safety, including the control measures. You could appoint one, or a combination of:

       - yourself;

       - one or more workers; and/or

       - someone from outside your business

       - If there are several people responsible for managing your risks, eg because of shift-work patterns, you need to make sure that everyone knows what they are responsible for and how they fit into the overall risk management programme.

      If you decide to employ contractors to carry out water treatment or other work, it is still the responsibility of the competent person to ensure that the treatment is carried out to the required standards. Remember, before you employ a contractor, you should be satisfied that they can do the work you want to the standard that you require.

      If you require additional information, please review your Business Unit Risk profile and / or NSS Facilities Management

    • How do I identify and assess sources or risk of Legionella?National Services Scotland, Public Health Scotland

      To identify the risks in your water system you, or a competent person who understands your water systems and any associated equipment, should establish any possible exposure to legionella risks, as listed above, as part of a risk assessment.

      Your risk assessment should include:

       - management responsibilities, including the name of the competent person and a description of your system;

       - any potential risk sources;

       - any controls currently in place to control risks;

       - monitoring, inspection and maintenance procedures;

       - records of the monitoring results, inspection and checks carried out; and a review date.

      If you decide that the risks are insignificant and are being properly managed to comply with the law, your assessment is complete. You will not need to take any further action, but it is important to review your assessment periodically in case anything changes in your system.

      If you require additional information, please review your Business Unit Risk profile and / or NSS Facilities Management

    • How is Legionnaires disease treated and what do I need to do?National Services Scotland, Public Health Scotland

      How is it treated?

      The illness is treated with an antibiotic called erythromycin or a similar antibiotic.

      What to do

      If you develop the above symptoms and you are worried that it might be Legionnaires' disease, see your general practitioner.

      It is not always easy to diagnose because it is similar to the flu. A urine or blood test will be helpful in deciding whether an illness is Legionnaires' disease or not. When doctors are aware that the illness is present in the local community, they have a much better chance of diagnosing it earlier.

      If you suspect that your illness is as a consequence of your work then you should report this to your manager, as well as your health and safety representative and occupational health department, if you have one. There is a legal requirement for employers to report cases of Legionnaires' disease that may be acquired at their premises to the Health and Safety Executive.

    • What are the symptoms of Legionnaires disease?National Services Scotland, Public Health Scotland

      The symptoms of Legionnaires' disease are similar to the symptoms of the flu:

       - high temperature, feverishness and chills;

       - cough;

       - muscle pains;

       - headache; and leading on to

       - pneumonia, very occasionally

       - diarrhoea and signs of mental confusion

      Legionnaires’ disease is not known to spread from person to person.

    • How do people get Legionnaires disease?National Services Scotland, Public Health Scotland

      People contract Legionnaires’ disease by inhaling small droplets of water (aerosols), suspended in the air, containing the bacteria. Certain conditions increase the risk from legionella if:

       - the water temperature in all or some parts of the system may be between 20-45 °C, which is suitable for growth

       - it is possible for breathable water droplets to be created and dispersed e.g. aerosol created by a cooling tower, or water outlets

       - water is stored and/or re-circulated

       - there are deposits that can support bacterial growth providing a source of nutrients for the organism e.g. rust, sludge, scale, organic matter and biofilms

    • Where does Legionella come from?National Services Scotland, Public Health Scotland

      Legionella bacteria are widespread in natural water systems, e.g. rivers and ponds. However, the conditions are rarely right 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, e.g. cooling towers, evaporative condensers, hot and cold water systems and spa pools used in all sorts of premises (work and domestic).

    • What is Legionnaires Disease?National Services Scotland, Public Health Scotland

      Legionellosis is a collective term for diseases caused by legionella bacteria including the most serious Legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever. Legionnaires’ disease is a potentially fatal form of pneumonia and everyone is susceptible to infection. The risk increases with age but some people are at higher risk including:

       - people over 45 years of age

       - smokers and heavy drinkers

       - people suffering from chronic respiratory or kidney disease

       - diabetes, lung and heart disease

       - 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 grow increasing the risks of Legionnaires’ disease and it is therefore important to control the risks by introducing appropriate measures

    • What are PHS duties in regards to Legionella?Public Health Scotland

      Under general health and safety law, as an employer or person in control of a premises (eg a landlord), you have health and safety duties and need to take suitable precautions to prevent or control the risk of exposure to legionella.  

      Carrying out a risk assessment is your responsibility and will help you to establish any potential risks and implement measures to either eliminate or control risks. You may be competent to carry out the assessment yourself but, if not, you should ask someone with the necessary skills to conduct a risk assessment. This can be done by someone from within your own organisation or from someone outside, eg an external consultant.  

       

      For further details, contact NSS Facilities Management.

    • What are NSS duties in regards to Legionella?National Services Scotland

      Under general health and safety law, as an employer or person in control of a premises (eg a landlord), you have health and safety duties and need to take suitable precautions to prevent or control the risk of exposure to legionella.

      Carrying out a risk assessment is your responsibility and will help you to establish any potential risks and implement measures to either eliminate or control risks. You may be competent to carry out the assessment yourself but, if not, you should ask someone with the necessary skills to conduct a risk assessment. This can be done by someone from within your own organisation or from someone outside, eg an external consultant.

      For further details, contact NSS Facilities Management.